Dealership couldn't fix this AC problem

[@Diagnosedan]

For Topdon producs used in this video; US link: www.topdon.us/products/phoenix-max Discount Code for Phoenix Max: www.topdon.us/discount/DIAGNOSEDAN10 European contact: [e-mail]

[@Lambros_Stefaneas]

Topdon, does not have a European store/shop?

[@julesviolin]

Re your question Dan....... Maybe the Body control unit had been changed ?? So many places had worked on it. Did you check all the vin numbers in the VIN configuration menu? I only work on Rover 75's and my T4 Diagnostics would have alerted me of a VIN mismatch. Then it offers a Reconfigure function which realignes everything with the security modules (if they are original!!) It's a shame all the original parts used weren't in the boot to play with as most were probably perfectly ok ! So many places these days throw a "parts roulette" at faults they have no understanding of. You and I on the other hand like to prove things with data and resistance checks before expensive parts are bought 😎 Keep going Dan, your workshop and techniques are amazing 👏

[@bismarckcro]

Hy Dan, please help me with clio 3 3door 2007 1.2tce, my boot pop up all time, did change microswich and lock, no change. Electrician check it and all wires can't find a problem. He think maybe body computer but is not entirely sure. Lock pop up and stay in open position, El motor keep working, know that because it is hot as hell. What would you suggest to check or give a diagnose Dan :).

[@kennethquick4165]

I think you would be an excellent instructor.

[@andrewwatson5360]

Had a similar problem with a Range Rover years ago. The A/C control panel failed and wouldn't power on the electro magnetic compressor clutch. My diagnostic skills are basic and crude in comparison but I did establish that the ac clutch would engage if hot wired and as a new cabin control module wax hideously expensive I installed a relayed switch to electrify the compressor when needed. It may have been a Heath Robinson fix but it was a welcome solution on 40c + degree days here in the Australian summer. Years on we now have three more recent and complex European vehicles (a BMW, VW and Mercedes) which I am attempting to maintain (and by necessity) using a reasonably capable scan tool as my earlier repair methods are largely ineffective. I am only just skimm8ng the surface of electronic diagnosis and your very well presented and carefully explained videos are apart from being extremely interesting very helpful. Thank you Dan for providing such valuable information and giving us all the benifit of your wisdom, logic and experience. It is greatly appreciated.

[@Diagnosedan]

Wow thanks for your great comment

[@cliffharrington6500]

Hi Dan, I used to be an automotive air con specialist, and these European cars were a constant battle to diagnose, your video demonstrates the issues inherent with them. The fact that the BCM is telling you it is a 2.4 DT engine after alignment is scary and that the ac controller is a one-time coding is terrifying. Given we know what the issue ended up being, another alternative fix which would have saved the customer money would be to hotwire the variable displacement control valve from the ac compressor clutch feed to ensure when the ac calls for cooling both the clutch and valve are engaged. This may or may not however create controller PID controllability issues. Another alternative would have been to use the old controller and install a compressor from a 2.4 DT which doesn't have the variable displacement control valve. Variable displacement in theory is a cool idea, forgive the pun, but I believe is an unnecessary additional feature and system component to go wrong and keeping it simple with a standard controller and compressor would have been Alfas best format. The stories we as diagnostic technicians accumulate over the years is amazing. Good to see you are documenting yours for the edification and benefit of others.

[@Diagnosedan]

The valve is PWM controlled, supplying it with 12V over a longer period of time might overheat the coil

[@reglard]

I think on an older car I would have put a 12v feed to a switch and a resistor to bring the voltage down to the valve.

[@reginaldigweike4002]

Nice one Clifford, I was going to suggest the same thing to Dan regarding the compressor, I'm a DIY enthusiast currently working on my Jag xf ac. A compressor from a 2.4d and the old control panel for a 2.4d should work straight away.

[@bigfootemobileauto9734]

Sure seems like it would and for a heck of a lot cheaper!

[@TruthTortoise81]

Yeah I was thinking either bodge the wiring or swap the compressor for one without a valve. Why is it scary that the panel was coded wrong? Seems very likely someone previously tried swapping it in an attempt to fix the AC.

[@johnguttink]

I'm a nurse, don't know anything of this stuf. Yet, I love to watch your video's because of the way you explain things.

[@todorkrustev9442]

Hi Dan, i think i can answer your question. First of all the two climate control modules are from different model year as you already found. First one was from the first Alfa Romeo 159 and was produced till early 2008. Afterwards they put the new module with off button and different drawings. As you already found the module needs proxy alignment procedure so to know what type of hardware it will control. You tried this with aftermarket diagnostic tool which i think was the problem. FIAT group (in which Alfa are) are not great fans of ordinary staff and so they use body computer to comunicate with various modules through can bus, but not the standart can signal. So there is slight difference. There is a program which is specific to Alfa Romeo and is called Multi ECU Scan. With that tool everything should work fine without need of brand new module. I have seen many ot these to be retrofitted with different type of extras including changing climate control from 2 to 3 zone with just proxy alignment done with multi ecu scan.

[@mod_incllc3235]

Excellent!

[@alinzmeul]

Hello. Your explanation appears to be reasonable and likely accurate. I am not an expert in this field, so I cannot confirm or deny your theory. However, I am curious about one aspect. If your explanation is correct, why was the dealership in Italy unable to resolve the issue? Presumably, they have the necessary tools and software to do so.

[@todorkrustev9442]

The reason for this is probably quite simple. They dont want to do it, as the module was second hand, it was from different model year and they could sell you something very expensive rather than investing some time to fix the problem. It will also require additional knowledge from the mechanic performing the task. Nothing is impossible but the question is at what cost.

[@alessandromelis2074]

and this is why you can break in to fiat cars by the can bus from the radar for the cruise controll

[@raphaelndubane6431]

@@alinzmeul excellent question

[@supers54]

There must have been a cold sweat moment when that new 1000 EU+ module showed the same incorrect engine code as the other ones! Great fix!

[@Diagnosedan]

Yes my hearth skipped a beat🤣

[@igotaction]

There is NO better start to your week than when DD drops a new video!!!

[@ilcooldj]

INDEED! i quit everything i'm doing to watch his videos the moment they're released! Once, i woke up to a notification altert & ended up enjoying DD going through an X6 at 2 in the morning 🤣

[@Diagnosedan]

That's great to hear!

[@frankmartin8471]

Watching Dan find and correct an elusive problem like this is almost as satisfying as having done it myself.

[@AlessandroGenTLe]

Alfa owner (156 before, Giulia now) and DIYer here: I don't agree about the "only one" proxy writing procedure: I did it MANY times on my Giulia 2017 with a simple but very powerful software called "MultiEcuScan" on my PC, connected with an USB-to-ODB2 adapter "odblink sx" and it worked flawlessly all the time: I added front parking sensors (using and reprogramming an 8 channel parking sensor module coming from another car), I reprogrammed an ETM (newer version with DAB and Android Auto) coming from a Stelvio, I activated the auto high beams, I activated the compass in my infotainment, I activated the adaptive cruise control, I installed and activated (modifying the proxy setup of my body computer) the backup camera and so on... The proxy is just a string of byte stored in the body (BCM) and the "alignment" simply copies it into all the car modules. You change one bit out of that 255 byte string and you can change the behavior of something. Of course you need to know what to do, but an alignment is ultra simple to do and can be done as many times as you want. Also, normally these modules doesn't show the engine type in their data, so that reading about 2.4l engine can be whatever your scanner sees from the proxy.

[@garyj2624]

I agree. Proxi alignment should write the BCM data to a used module. Done it myself with Autel scanners and data written to used modules correctly and fault codes cleared. Happy to be proven wrong as usual....every day is a school day.

[@Kerleem]

You're a mechanical genius and it shows. So many others (including dealerships) gave up because it wasn't worth their time to actually figure out what was wrong. Super awesome how you diagnosed this!!

[@fredflintstone8048]

Even if they thought it was worth their time, if they took all the time in the world, they could not have fixed it. They don't have the mental tools in their toolboxes. You have to be smarter than the technology you're working on if you want to be able to have a ghost of a chance of fixing it... With each passing year cars get more complicated.

[@kathrineculver696]

I mean let’s be fair, it’s Italian so it’s already over engineered and not in a good way plus Alfa’s are notorious for horrible life expectancy. These are essentially cars that look visually stunning but are normally only kept 2-3 years because of how badly they’re done.

[@Diagnosedan]

Thank you!

[@jacquesvandyk4645]

​@@fredflintstone8048

[@Zion-jw3gm]

@@kathrineculver696 I've had my Alfa 156 for 23 years and it's my daily driver. I have one electrical earth issue only, everything else has been maintenance you should do on any car. And that's the problem with most cars, lack of proper maintenance.

[@aclmotorsport4420]

Having worked on Fiat/Alfa for many years I have seen this kind of typo in ECU settings many times on their cars. It looks to me like it just says 2.4 instead fo 2.0 as the 2.4 diesel is a 5 cylinder and therefore a 20 valve engine, so basically it's just a typo and they are not uncommon. Almost all control units are not interchangable on Fiat/Alfa cars. Nice to see an Alfa on the channel. Great Video, keep them coming.

[@ruimvp]

Build a 5€ electronic circuit with 555 timer that puts a 65% duty cycle signal at that frequency in the compressor when ac on. LoL.

[@Diagnosedan]

😁

[@Spark-Hole]

What is the maximum voltage 5v or 12 v

[@ruimvp]

@@Spark-Hole 14V but works as 14x0,65

[@coldfinger459sub0]

I was thinking the same thing and you can hook the Arduino up to a evaporator fin or pipe temperature sensor on the suction line 2 very duty cycle depending on temperature so you have full control . Easy middle school high school level Arduino coding simple cheap software $.50 thermistor . If it was my own personal car. I’ve never seen this problem and I hope I never do that took some research in frustration glad you found the problem and fixed it.

[@barryphillips7327]

Diagnose Dan DID i again, we need MORE like Dan with modern complicated cars!!!!!

[@sacharaffi3834]

Hi Dan! I was recently struggling with the same issue on my 159 2.0jtdm, same a/c control unit, same compressor. Swapped the clima control with another used one and done the proxy alignement but nothing still happened. Thanks to this video today I repaired the broken fan on the clima control unit sensor and put it back on the car and now everything works fine. I love my car but I hate Alfa's engineers with all myself😂

[@davidhall3747]

As a Mechanical Engineering Consultant, I appreciate Dan for increasing my Knowledge.

[@Diagnosedan]

Thanks David

[@davidhall3747]

@@Diagnosedan Dan: Please diagnose cars with Speed/ Cruise Control problems. I noticed most scan tools don't have the Bidirectional Control for the Steering Wheel Switches.

[@martynbates6697]

Dan you are the King of diagnostics, every morning during my morning coffee break I religiously watch one of your videos and your tutorials are just awesome. Watching a few each morning just relaxes me and sets me up for the day.

[@Teddykhil]

What an incredible gift, and educated with mechanics "brain". I only pray you are teaching others your gift that they too will be a "switched on" mechanic to solve and fix problems with cars.

[@pavelppp888]

As always - incredible reverse engineering skills demonstrated. As an automotive engineer, I highly appreciate that and I also know how hard and time-consuming is to acquire those skills with the time. All best regards from Bulgaria! 🇧🇬

[@Diagnosedan]

Hi Pawel it can be quite time consuming at times, especially because there are so many different brands / models / systems

[@Random-nf7qb]

ooo, zdr

[@pavelppp888]

@@Diagnosedan yeah, the wide variety of brands and platforms generations is what make it so challenging.

[@demafklappers]

Hi Dan, thank you for the interresting video's. Now you can open up the new 1080,00 EURO control-unit and look for a EEPROM to readout or a uPC to readout the FLASH-memory and save the virgin dump in case you need it in the future. Then you'll always be able to virginize every simulair control-panel en recode it. Greetings from a electronic repairer :)

[@damienh4357]

You truly are the Sherlock Holmes of automotive diagnostics. Alfas can be tricky at the best of times (I've owned 8). Build quality can vary wildly even within the same model. Probably something to do with the temperamental nature of Italians throwing any old part in at finishing time on Friday. Great job.

[@abdul-kabiralegbe5660]

😂 Your last sentence.

[@Diagnosedan]

You have got to love the Italians😁🇮🇹

[@Infiniti25]

That was the same as the Peugeot staff then...

[@sahuvikramindia]

I am a DIY guy with mercerdes cars. Our family has got 6 of them and i think its always best to stick to one brand and know all about it so when they break its easier to fix. My 3 year old son is named daniel, i call him dan. And one day i would love to visit your shop, i recently saw one of your videos where your son was helping you out. Coming to this car, i think hot wiring the control valve with 9 v would have done the unlucky customer a great saving but i know that a master technician of your caliber would not guarantee such work and so you did not opt for it. Your videos bring a great deal of knowledge to this world and also the simple and efficient way that you explain stuff is just too good.

[@thebaldmechanichardatheari1124]

What a head scratcher. Good fix. Remember years ago there was a v-8 engine which could not get engine to warm up. With a lot of trail and error we found some one put the wrong head gaskets on. They were ported in wrong place and bypass the thermostat.

[@kevace1985]

Wow this probably was a very aggravating diag!!! I can only imagine that pissed off meter was relevant to what ever engine it was you were working on!!!

[@Diagnosedan]

That must have been a hard one to find

[@vukojeskocajic4804]

I can imagine the happiness of the owner and to how much people he will recommend Dan. From now on Dan is his God :D Dan is my God too :D

[@ΝίκοςΒουγογιαννόπουλος]

Maybe some has messed with the engine ecu or body computer? I would suggest to use multiecuscan to read the modules and do the alignment on the next one! I had problems with the AC on my 147 1.6L 2002 and no one would try to fix it and the costs they gave me where too high for replacing random parts with out beeing sure if they are defective... i ended up replacing my self the evaporator valve and solve the problem after 4 years with no AC. For once again you did a perfect job and the customer agreed to fix this amazing car becouse he trusted your diagnose after all these he went throuh!!!

[@gartheligon140]

Factory service manuals and theory of operations is a must.

[@Nievesowns]

This video was a random recommendation, but maaan, from a fellow IT tech, a proper way to diagnose step-by-step, you earn my respect in literally 3 seconds I saw this video. Wishing you all the success!

[@Diagnosedan]

That's great to hear, thank you!

[@Nievesowns]

@@Diagnosedan Passion and professionalism shows instantly 👌

[@yamahattr6006]

How do workshops get away with charging for parts that are not fixing the problem surely they should have to fit the Old parts back on the car they are incompetent you are the top man Dan

[@octaviannistor7293]

Hi Dan, Regarding your problem with the engine type it might be that someone has changed the vehicule configuration inside the BCM from 2.0D to 2.4D , you can verify and change that inside the BCM. Always a pleasure to look at your videos. Wish you all the best

[@raystorey3670]

Had this problem with an old ford. Car had been flood damaged so a used bcm was installed and re-progamed but one data had been wrong this put the throttle pedal all out of sink, thinking the used bcm was also faulty, relplaced with yet another £200.00 used part re progamed and worked fine. Had the used part tested and they found nothing wrong apart from it was re-progamed wrong !!

[@Diagnosedan]

With my aftermarket tool i couldn't see the engine type in the BCM

[@jeroenorriens2590]

To shed some light on the whole configuration mystery: this happens more often, fiat/alfa have always had a funny diagnostic system. I discoverd this when a punto 1.4 told my delphi it was a 1.2😅 had to take it to the dealer for programming afterwards (multiair failure) and they told me its the way the coding is translated in the scantool, since it doesn't correlate with can protocol some tools do read correctly and some don't so fault codes will match up but the description won't always match the code itself I.e. lost in translation.. literally

[@anvilsvs]

This stuff will make you absolutely crazy. I did the longest army electronics school in 1965-66. Been working on tractors and trucks since age 10 in 1956. Was an IBM large systems customer engineer. Speak 5 programming languages. Have my own shop and also have a good scope, which almost no car mechanics have. Started with A/C work in 1970. This is about as bizarre as a number of other almost unimaginable things I've seen over the years. Just makes your head hurt.

[@ronnierobinson1502]

I don't know how you do it dan....some of the hardest faults to find and you always fix it, keep the videos coming mate, great job😀

[@Diagnosedan]

Thanks Ronnie

[@S2NAZ]

Italian car manufacturers and the odd crap technicians have to deal with. Nothing is straight forward. You did a great job diagnosing it given the other technicians that were unable to repair it and installing the wrong dash panel.

[@MrLuvallcars]

Hi Dan, you mentioned that the new climate control module inherits the data from the BCM while doing the proxy alignment. Could it be that the BCM has 2.4 diesel data stored instead of petrol data that's not causing any DTCs as far as the BCM is concerned? Thanks for always bringing great content 🙏

[@aboyd1988]

This was my thought, too. Could the BCM have been replaced/programmed incorrectly?

[@lo1234-w9r]

He discovered the control module wasn't working and reported the wrong engine size? Big red flag, I would have reprogrammed the BMC right there.

[@hightttech]

​@@lo1234-w9r: If you reprogram BCM, isn't AC module still a problem due to limit of one synchronization session?

[@JasonSpiffy]

Sometimes I think you struggle with pronunciation more than fixing the impossible problems. Always love your videos!

[@fred1960]

Dan, you're brilliant! I learned a lot again. It's shocking, nearly criminal, how they make these parts only one-time programmable, so you cannot use it on another car. A market opportunity for hackers I would say.

[@Diagnosedan]

There are many technicians out there that can virginise these modules, but this one is quite rare and i could find no one that had done one before

[@mickl8212]

I had an issue in 2011 with my 2006 Honda Civic 2.2 iCTDi, the AC wouldn't work. Short story, it was at Honda dealer for two weeks. They ended up getting a donor unlocked test ECU from Honda UK for them to try on the car to make sure the ECU wasn't faulty. It worked! So they refitted the original ECU to the car while they were in the process of ordering a new ECU from Honda. The AC started working properly! So the original just needed a reset by powering it down for a while. It's still working fine now 🤣 RE the Alfa, someone somewhere made absolutely sure that people are getting robbed by not allowing any second hand electrical part to be paired to the existing ECU, that's an absolute con! Well done on the methodical and logical fix.

[@1planenut62]

Amazing! I was an aircraft mechanic for around 40 years. The industry needs people like you. Aircraft now are going all computer controlled.

[@shinishini6047]

Industry needs them but people who could be capable of doing it are not valued enough or at all

[@TheFrenchPug]

You're amazing Dan. No wonder nobody could figure that out. You had to be a rocket scientist!

[@annaplojharova1400]

It could be the 2.4l engines were actually fitted with two types of AC systems (or the 2.0l as well). When coding, it also could be the controller not only reads the config from the rest of the car, but as well is checking the presence of various components to determine the AC "hardware" type. I would guess the engine type is actually necessary only to adjust to the rpm range (diesels have smaller idle vs redline range) and whether the engine controller needs the "elevated idle" request signal when the AC is running (as the petrol, mainly the smaller ones, do; diesels have way faster acting and more capable idle governor so do not necessarily need such explicite signal from such high load devices as the AC is)

[@perchancethishandleiswens]

Found your channel through this video, glad I found it.

[@paulhutchins6019]

I love the way you take nothing for granted, even the checking that your equipment is working during the diagnosis. Well done. Could you have wired that valve independently through a micro switch or something to save all that money? I realise that it's not a factory approved method. 😉

[@MattyEngland]

You could, but it wouldn't be a simple on/off type signal, you would need to use a microcontroller to provide the correct PWM (Pulse Width Modulation) signal. If you look at the oscilloscope at around the 21 minute mark, that square waveform shows that the signal turns on and off many hundreds of times a second.

[@TheGamerFiFtIn]

And how would you know the good pwm signal ,

[@alexbik]

Dan showed the compressor worked by applying voltage to the valve. But I guess temperature control wouldn’t work properly without the valve being controlled with the right signal.

[@TheGamerFiFtIn]

Exactly

[@MaltiPoo23]

"Test the tester" (electricians' saying)

[@stevenmckechnie4380]

Well dan , you've fixed it again. To answer your question the silly bill programmer simply called it 2.4 and the computer does not care of it's name just it's coding.

[@frankp.2831]

Absolutely incredible diagnostic and fix. Without taking anything away from all the other diagnostic wizards out there, this one has got to be my absolute favourite diag.

[@Diagnosedan]

Wow Frank that's great to hear

[@petermc1743]

Congratulations Dan. I wonder how many others would have had the intelligence and tenacity to work through this one? Not many I suspect.

[@gplusgplus2286]

Probably an error in mapping tables in your aftermarket scan tool, only comparing with an Alfa/Fiat factory scantool will tell. At least coding worked well or you could have bricked the new ac control panel.

[@Texasknowhow]

I was thinking the same thing when he said he was going to move ahead and code the new one… what if he locks that one up too!!! Oh man.

[@calholli]

I was thinking the same: Try a different scan tool and confirm the same issue, or is it just a glitch.

[@maciekglebocki9640]

I had the similar issue with that car at my shop. Customer brought 3 or 4 used panels with good part number. None of them worked. I personally think that it's a problematic module that fails regularly because proxy only aligns the modules to bcm not the other way round. Think of it as a MAC adress that gets noted to BCM. You could leave it an dit will work but the odometer blinks.

[@Diagnosedan]

You could be right!

[@mercedes_and_more]

Talk about quality over quantity. You are the only one of two channels they i subscribe to that i don’t skip a second of the video 👍👍👍

[@DavidSuttoninSpain]

Another excellent video Dan, you amaze me with your determination to get these faults sorted out, thank you once again for an interesting video.

[@Diagnosedan]

Thank you David

[@markhammer9975]

Thank you for renewing my hope in humanity by being that which makes people's lives better. You really make something complicated into something simple for us to understand. Diagnose Dan, fixed it again!

[@SuperMarioDiagnostics]

The 2.4L/1.8L coding may only be one of the many coding parameters that are addressed during the proxy alignment. I can almost guarantee that there's a dedicated coding parameter for variable displacement compressors vs clutch only

[@georgemichael45]

Try a proxy alignment with the MultiEcu tool

[@ousmanesarr7287]

Yes and it also save the number of ecus on the network loop/ can and do a handshake with the other. I remember playing with a fiat 500 that has a defective bcm. Tried putting a used one but until i did the proxy alignment all other modules was setting no comm faults with bcm. After proxy alignment no more communication fault. But still no start. After that realised the immo data was a one time thing .had to get it brand bcm from dodge and programmed it thru witech then redid proxyalignment and virginize and program keys with im508 to get car running

[@Diagnosedan]

You are right Mario, there are many variables for this module / system. Great to see you here!

[@fulanito494]

No words man, amazing job. It would be great if your diagnosis tool show you the values returned by the BECM. Maybe the scanning tool shows 2.4 JTD with different digital values or maybe there is some other parameter that was indeed provoking the issue, like VIN number or something like that. In any case happy and cool customers so a happy ending.

[@HolgerWild]

Hi Dan, i love the way of your videos are made - intelligent and with a portion of humor! Try to put the wrong programmed module into a very cold fridge (about -40°C) for a few hours and let it warm up slowly and try to reprogram it. The EPROMs in the device may lose it´s programming and may be reprogrammable for another time.

[@MrForcat]

That’s the tip of the day!! Worth trying

[@jimmymatchubar8700]

Diagnose dan fix it again...and shed some light again..

[@jort88]

Maybe the BCM was replaced as some point, and it's a 2.4D? 🤔 VAG is similar with their BCMs. A3,S3,Rs3 use the same BCMs, but are coded (VAG verbage Adapted) differently I believe.

[@Diagnosedan]

Bcm and PCM need to stay together for immo reasons its highly unlikely the Bcm was changed.

[@TheNuckle1]

I relate to your comment about thinking it will just be another broken wire, not interesting. One of my favorite parts of being a technician is when you get a reading you did NOT expect to see. Time to get your thinking cap on. Great video Dan!

[@Diagnosedan]

Thanx Sam

[@milosmilovanovic6493]

Using multi ecu scan you can recode all those modules under proxy aligment. You can change the vehicle configuration as you please and by doing the proxy procedure it calls out all can modules to sign in, then recodes and reorganises all of them. Very usefull tool for the fiat group.

[@Diagnosedan]

Maybe i should get that tool although i dont work on Fiat or Alfa alot

[@CitarNosis317]

That info is useful, but how comes the Alfa specialist who worked on it, didn't know this or didn't have the tool? (Or is it that expensive?) I looked at Alfa/Fiat before, but to me, it's an Italian BMW. Nice looking cars with nice performance, but the maintenance/upkeep can be very, very expensive. Shame though, they do look really nice.

[@piletu]

Hi, Dan! About that false reading 2.4 16v. The 2.4 engine is five cylinder, so it supposed to be 2.4 20v. I think You should try connecting different diagnostics tool. Best regards!

[@WillieJu]

Great diagnosis Dan, as always - but if t was my car, I would have just hotwired an extra switch to control that valve, and save me a lot of euros.

[@phonotd]

That would have meant the compressor running at maximum all the time the switch was on resulting in no temperature control and the problems that brings with it such as icing up and so on.

[@Diagnosedan]

Its a PWM signal Will, you can't run that valve all the time on 12V its not designed for that. The coil will overheat

[@dustcommander100]

Amazing diagnosis. So difficult to work thru those computer issues, especially with the possibility of wasting so much money! I remember a non-automotive computer issue with a German drive system in the plant where I worked - a series of drive motors up to 600 HP stretched polyester fibers. If a leading zero was used in one of the drive ratios (0.245 vs .245), the machine would run away and break the fibers. If the leading zero was omitted, it worked fine! ANYTHING is possible with computers and coding. And there are many things that CANNOTY be made right - we can only make them work. Takes away from the satisfaction of identifying a root cause, but we have to live with it.

[@Diagnosedan]

Thanks for the comment 👍

[@mckoylach1622]

DiagnosDan,perhaps the sole mechanic that able to solve problems that some other mechanics couldn’t fix. You’re the man

[@raymondjacobs8335]

Dan, Thank you again for your Comprehensive investigation, into why and how.

[@dcasteaux9181]

Gotta love the built-in obsolescence team at FIAT.

[@ajfurnari2448]

Fix it again Tony!

[@khalidacosta7133]

Most likely FIAT used a programming chip that can only be written to once before the flash memory chip starts degrading, hence why coding not allowed.

[@calholli]

Insane.. Imagine all this complexity just to turn on and off an AC compressor. lol.. wtf were they thinking. Watching this channel just keeps reminding me to NEVER buy a Euro car.

[@user-te1le7ck6b]

Your customer is mad 1000 euro for ac cheaper to get a new blank chip soldiered on to existing unit , any tech with some hex editing knowledge should be able to achieve it.

[@Diagnosedan]

FIAT= Fixed It Again Tony

[@havetahunt1711]

Dan i came across your video because tge dealer is u able to diagnose and fix my wife's AC. You really know your stuff. I hope some of your videos can help me troubleshoot her problems in her 2011 Ford Fusion. Great job keep up the content.

[@peterhodgkins6985]

Wow ! That's crazy! Seems to me it'd be a lucrative business to 'virginize' those things! They're expensive automobiles to be doing hipshot diagnosis with! ;) Great work Dan!

[@engeneer_ru5827]

In my area, used parts are often used. Control units are constantly reprogrammed like new... This is a business for many.

[@Diagnosedan]

A lot of junkyards have the capability to virginize modules because they are worthless i they dont

[@c14back2nitrogen9]

the problem is we have too many useless professionals .dealers making more money selling parts then selling cars. God bless you sr. You make it look easy.if I had the means I would pay you to be your helper so I can learn and become useful technician as you are.

[@The_Redkween]

I was surprised to see the clutch engaging and disengaging with a variable displacement compressor. I thought the clutch was engaged all the time when the AC was turned on. Great job, Dan! You are the greatest!

[@calopii]

I don't think it is actually a variable displacement compressor. It just modulates the opening/closing of the output valve with that PWM signal he was showing on the scope. When more cooling required, the PWM goes in the direction of 100%, when lesser cooling required it goes down to 0%.

[@Diagnosedan]

Thanks for the great comment Scott

[@gunnarlandin3258]

This kind of compressor has both the clutch and the pwm valve so that it can stop it from turning when not in use. Other pwm only compressors turn all the time even when the compressor is at idle.

[@aboyd1988]

@@gunnarlandin3258 that sounds like a recipe for premature compressor bearing failure.

[@theweekthatis]

It's for better fuel economy, when the A/C isn't needed at all, the compressor can be disconnected entirely.

[@mostafamohamed3022]

Good job Danny I am automotive engineer from Egypt and I benefit greatly from your work, keep going

[@Diagnosedan]

Thanks for watching

[@ritchieschofield1185]

Once again the master at work. Patience and perseverance. Another great find Dan. Very bizarre. Theres nothing better than that buzz of finding a fault, especially when all else have failed. Great video. Bring on the next one!

[@Diagnosedan]

Working on the next one😁

[@daipower1]

Dan, I love the way you explain everything step by step.

[@danielkoontz6732]

So there's a PID for engine type.... Is there a PID somewhere for calibration/software ID? Unfortunately, I don't have an answer for you besides theories, but, I will leave you with this story: I'm a GM tech at a dealer. Early this year, I had a 2021 Chevy Camaro 6.2L. Had a code for fuel pump pressure low. Vehicle started normally. But, when going wide open thettle, it did not stutter, it just took longer to react. Accelerator pedal pos 1 and 2 ok. Same with throttle 1 and 2. Watching scantool data: High pressure fuel read 50ish PSI about all the time, regardless of throttle engagement. Low pressure read 0PSI. I thought about the high pressure pump reading that and considered that it could be strong enough to pump something on its own. Anyways, next step, replaced the low pressure fuel pump. No more code, no more slow reaction. Great! Right? Well no, actually. Checking scantool data line for low pressure fuel would intermittently drop to 0psi. Meanwhile, high pressure fuel would always read properly. I thought, oh no, I messed up a connector. Investigated: no wiring problems. Called technical assistance for GM. Was told let's try a few things. Replaced the low pressure fuel pressure sensor, the jumper harness from the body to the fuel tank, and strung new wires from the body side connection at the jumper, all the way back to the ECM. Still, I would have an intermittent 0 psi on the low pressure fuel reading, but I would have no drive ability concerns and no codes. So, after multiple back and forth with technical assistance, I eventually get a call from software development engineer for the Techline Connect software we use at the dealer. He said, sorry, it's a software anomaly. Ship the vehicle. We'll patch this in the next update. My response, "... thanks..." lol So, all that said, my experience tells me that the scantool interpreted the data incorrectly. But, for your scenario, it could be the vehicle saying incorrect things. Who knows until you know.

[@devenair681]

Great to see a real technician diagnosing the fault to component level rather than just changing bits to see if it fixes the issue. 👍🙂

[@corbettknowles9942]

It's a glitch with your top don scanner if u were to hook up the Witech micropod it will show 2.0 liter diesel

[@jim9355]

I had this exact problem. I just did the clever thing and wired it to the AC clutch. Worked Great.

[@GraditelMacedonia]

Maybe BCM like that AC control panel is borrowed from 2.4 JTD...

[@kevinbarnesworship5517]

Great video, I would never thought that would be the fault why the AC not working... I am now following your video to advance my diagnostic skills, I am currently at basic... Thank you for the information shared. I have never watched another channel that walk you through step by step like you do.... 👍

[@tabezulu5686]

You are very good at what u do bravo

[@Diagnosedan]

Thank you very much

[@ukexbreakdownman]

fantastic job admire your persistancy you can see why previous garages gave up why cant the manufactures make one control panel that is programmable for all models dont tell me that would be too easy great video

[@johnmehaffey9953]

Awesome diagnosis Dan, only thing I can say is that nearly every motoring journalist says that yes they are a dream to drive but be expected to spend a lot of money on repairs as they are not very well made, brilliant post

[@Diagnosedan]

Thanks John👍

[@CJ.A-C]

hi danny clive from london. good to be back on your programe lots more A/C stuff please

[@paulorosa1364]

Thanks for sharing your time and knowledge Dan. Much appreciated. I'm starting to find more and more cars that come to my shop where fault codes have been written out of the ECU by some of these tuning shops, and engine operation is affected in someway and its almost impossible to diagnose. Lately what I do if I suspect that the ECU has been tampered with I re flash so that I know I have a good foundation to start from. Keep well and all the best.

[@Diagnosedan]

If we suspect the vehicle software has been tuned, we won't accept the diagnostic job.

[@GustavoFreeng]

Dan, you are the best! Your videos are better than crime movies.

[@AMGTOM]

Hello Dan, Nice video, I think that the used part that the customer brouht was also faulty with same problem, means no power control of the AC valve.

[@Diagnosedan]

You could be right!

[@ilcooldj]

Am happy this channel is back into real diagnosis....DNA of DD is retored. Great video Dan.

[@Diagnosedan]

Thanks!

[@connector8748]

Dan!! You are the beast of diagnostics.👍

[@Diagnosedan]

Thanks!

[@ivaneu1]

I really appreciate when your video pop-up on my mobile phone. Thank you again together.

[@Diagnosedan]

😁😁😁

[@agblastful]

It is your aftermarket scan tool. For the cars from Fiat group (Fiat, Alfa Romeo, Jeep, Suzuki...), as a diagnoze, it is advised to use Fiat multiecuscan or Cantiecar (the best). Btw, the 2.4 diesel engine is 20 valves, the 1.9 diesel is 16 valves, so your scantool couldn't figure it out correctly. Considering the car is from 2012, the original climate control module must have been replaced from the start with the wrong one (the one with MONO is the pre-facelift one, installed between 2005-2008. After 2008, it is the the one with OFF button and with the 2 little red and blu humans :-)

[@Diagnosedan]

It sounds like you know quite a bit about Alfas!

[@agblastful]

@@Diagnosedan I own one, so I need to, since Alfas don't break, they stop to be admired (quite often!) 😂

[@mikechiodetti4482]

Thankyou Diagnose Dan for this video. If I ever encounter a Euro vehicle I'm calling you for help.

[@gplusgplus2286]

Someone probably thought by changing the coding to 2.4lit they would get the bigger engine output, lol.

[@calholli]

checks out

[@Diagnosedan]

🤣🤣💪

[@neutrodyne]

Someone suggested to just add a switch under the dash to turn on the valve. first, adding a switch to turn on the compressor valve sounds good however these computer-controlled systems don't always work the way we think they would. Most likely that valve is controlling the temperature inside the car. If you simply added a switch the compressor would probably run full force and freeze everyone out. I'll have to hand it to DiagnoseDan he is one very smart guy for figuring this one out!

[@valentinnedelchev1096]

Hi Dan, Very interesting video! Keep up like that! :) Normally when there is a node on the CAN bus which is not being recognised by the BCM, the symptom, apart from not working functionality, is also a flashing odometer on the instrument cluster. This is certainly true for the lower variants of the clusters in Alfa/FIAT/Lancia which cannot show graphic images. Your vehicle is with the higher cluster variant, so I'm not too sure if the same will be true there. To your question, have you tried to read the identfication of other ECUs too? For example the Instrument cluster, the ABS module, the Blue&Me module.... My point is that maybe if the BCM is configured for 2.4l JTD engine, it will also set this configuration to the other ECUs aligned with it.

[@Diagnosedan]

When i disconnected the climate control module the odometer started flashing on this car, the as build data in the BCM was 2.0. I made sure of that before ordering a new module 🤣

[@dirtrider3526]

As a tech in the states, I absolutely LOVE diag. Exp on a crank no start. Even more when it's been to multiple shops or the owner gave up. I would love to work with you bcuz u are through. I don't like condemning a part unless I have several tests proving its wrong! Exp now ppl are struggling. Every shop I have been at doesn't charge a diag fee so if there's a code, change the part. I HATE that! So I keep to myself and test n test. Then I test some more. I no they think I'm slow but I make sure when we call the customer I am 110% confident when they pick it up they are happy and they come back!

[@glg2029]

Proud of you Dan, excellent comprehensive troubleshooting. You earned a subscriber who is looking forward to more videos from you.

[@Diagnosedan]

Thanks for Subscribing!

[@mansonnanson8294]

2.4 is what the bmc has stored inside. When the new module was installed and synced, it took all the details, but it did not affect the valve setting.

[@richardwilliams7020]

Another great video Dan, thank you. I've been an a/c specialist for 18 years. I had a similar issue with a Honda where the control head had been exchanged with an incorrect one around 15 years ago and it took me hours to figure it out. I always ask now if anything has changed since it last worked, any work on the engine or even battery changes - all have caused malfunctions in the a/c. There's a tool available that produces a pwm signal that you can use to drive the control valve safely.

[@Diagnosedan]

You are right i've got a PWM driver, i actually used it in the previous video. Supplying the valve with 12V for a short period is alright, but you are right i should have used a PWM driver

[@simonfowler7561]

In my opinion and experience Italian cars are fine as long as they are SMALL cars. The Panda and the 500 for instance are excellent workhorses and last many years. The problems grow as the cars grow and for me the larger cars MUST be German for quality and reliability. Thanks Dan another GREAT video!!!! Simon

[@armyvet92]

Excellent Dan !!! Glad you decided to use this for your video. If you interrogated the other modules does any of the other say the same eng. code? That would be my 1st question if actual build data / coding is 2.0 or 2.4. - If other modules show 2.4 but verified build is 2.0 then next step would be to verify with another scanner.

[@dazaspc]

Indeed I would say a shortcoming with the scanner and the OEM not keeping to their standard.

[@Diagnosedan]

As build is 2.0 i made sure of that before ordering a new "expensive" module 🤣

[@armyvet92]

@@Diagnosedan Absolutely sir. It is just some of the stuff that I run into here in the US, where kids or even “Sub-Par” repair facilities try to MODIFY or TUNE. Especially with Audi / VW & BMW. I have gotten to the point that if I see the vehicle has been modified…. Suspension, Audio, or Aftermarket Tuning or they say that they installed a USED MODULE. I will not even bother with them. They try to “RECODE” stuff and do not know what they are doing.

[@gunnarlandin3258]

@@armyvet92 at least VW can be recoded over and over you don't need to buy a new module every time.

[@alioufaye5919]

My best guest. You already answer it somehow., they may have reprogrammed the BCM by puting 2.4 diesel that still being dump in the new control module during prosy alignment.

[@TheKeenMechanic]

What a Great video again Dan. One of my favourite so far and I have to say I have watched every single one more than once. I also read all comments so far and was asking myself the same question: was there an option to wire a separate switch for the manual operation of the valve to save over €1000? Great video and I would love if you could do a 2nd part update with the learnigs of what exactly was the problem with the 2.4 2.0 and 1.8petrol

[@mph5896]

No. Its a pulse width modulated signal based on the needs of the climate control computer. MAYBE if a 2.4l with a non variable compressor would fit, that might be a fix.

[@TheKeenMechanic]

@@mph5896 How was he able to manipulate it with the power probe if it is pulse width mudulated?

[@itstheterranaut]

I'm not Dan (obviously), but I don't think a simple on/off switch would have worked. For these externally-controlled compressors, it would have to have been something which can adjust across a range using PWM.

[@antonisantonis655]

@@TheKeenMechanic when he powers it with the probe, the compressor work at 100%, but sometimes you want it to work at 80%, 50%, 20% etc, and this is happening using different wides pulses which are produced by the climate control panel. A simple on/off switch will make the compressor work all the time at 100%

[@mph5896]

@@antonisantonis655 Yes sir!

[@promischristodoulou3681]

Excellent, your videos remind me of 2 things. Information is king (wiring diagrams and pin data in this case) and process. Really enjoyed this one.

[@Diagnosedan]

Information is very important

[@maikelnait1051]

You constantly blow my mind👍👍 Absolutely love Your videos! Thank You for doing this 🙏

[@Diagnosedan]

Thanks Maikel

[@abhijeetsurve8199]

I am from India......very useful diagnostic......ideal diagnostisdan

[@cccspokesmanandcofounder]

Yes!!!!!! Dan’s back!!