Scan Tool Autel MS906BT and Micsig Oscilloscope Audi Volkswagen A/C Diagnosis Fix Code 00457 00256

We diagnose the reason why the AC is not blowing cold in a 2013 Audi S5. Many Audi Volkswagen vehicles use the same system design. In this case the air conditioning was not blowing cold because the ac compressor was not be commanded on by the ECM. We go through the steps to diagnose exactly what is causing the issue using an Autel MS906BT scan tool and a Micsig Oscilloscope. Audi Volkswagen trouble codes 00256 and 00457 are common codes when experiencing no a/c complaints. The check engine will not illuminate. Thanks for stopping by the channel and feel free to leave comments and questions down below. -Glen (Ozz)
*A/C Pressure Switch* amzn.to/3h3e7DZ
*Autel MS906BT Scan Tool* amzn.to/2Ruq9LE
*Micsig Oscilliscope T01104* amzn.to/3h3FFsM
Check out some cool tools that Ozzstar likes to use: www.amazon.com/shop/ozzstar
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[@acidid]

What a great teacher / lecturer you would make, extremely clear and easy to understand. Thank you.

[@ozzstars_cars]

Thanks acidid!

[@vw_mods_4711]

Great video, love the bit where you used the scan tool to prove the pressure switch was bad 👊👊👊

[@ozzstars_cars]

Thanks, that's my favorite part too.👍

[@jimthecarguy]

Nothing is easy any more . Nice explanation of the diagnostic procedure.

[@ozzstars_cars]

If it was easy anyone could do it. 😁 Thanks Jim!

[@amazingvideo2869]

That was the most correct way to do it that I've seen, great Vid!

[@stuzman52]

Great diagnostics Glen. And as you said, it helps to have the right tools to make the correct diagnostics. Have a great week!

[@ozzstars_cars]

Thanks Terry and hope your doing well.

[@MrGentleNick]

This has been really informative. Just like all your other videos. You are a really cool dude. Thank you from England

[@ozzstars_cars]

Thanks Nick, I appreciate your comment.

[@kevinpalmer7452]

Excellent diagnosis and follow up repair

[@ozzstars_cars]

Thanks Kevin

[@dalebabbitt6185]

Awesome video and lesson!!!! When you were showing the Oscope data packs there were nice, segmented packs. But then you dwelled on one pack that was a bunch of signals all together. No spikes, as you pointed out, but why this data pack so different than nice segmented packs. I learn a lot from your videos!!! Thank you so much!!!

[@ozzstars_cars]

That's the pack zoomed way in. Looking at the details. Thanks Dale

[@spelunkerd]

The complexity of these AC systems is a little intimidating. You nailed this diagnosis, thanks for bringing us along!

[@ozzstars_cars]

Thanks Dave.

[@sambitar8448]

SIR, YOUR PRESENTATION IS AS CLEAR AS THE SON LIGHT. THANK YOU.

[@ozzstars_cars]

Thanks Sam

[@patrickkateule815]

@@ozzstars_cars do you teach programming

[@ozzstars_cars]

@@patrickkateule815 no I do not.

[@eyesalooking]

This goes to my saved Scanner/scope folder and I subscribed. I have a Uscope and Maxisys MS906BT so I am trying to learn as much as I can on how to use them. I purchased the Maxisys MS906BT based upon your recommendation.

[@ozzstars_cars]

With those tools you have some solid diagnostic equipment!

[@hayguey7952]

Thank u.im actually diagnosis an ac problem and ur video help so much.thanks just made 300 bucks with ur help.

[@ozzstars_cars]

I'm passing the tip jar. Link is in the description. 👍

[@RustyGlovebox]

Great instruction Glen, this will be a big help

[@umbrawakanda9718]

My man brought out the oscope! Ballin

[@ozzstars_cars]

Sometimes we need heavy artillery to win the fight.👍

[@gerhardpet1]

Thanks for the content. Very helpful

[@ozzstars_cars]

Glad it helped.

[@mikemaifeld6280]

I have a 2008 Yamaha Roadstar Silverado it's a great bike. I also have a 1980 Suzuki GS 1000 to play with. Also got the old corvette 1991 back in shape with your guidance thank you

[@ozzstars_cars]

That's awesome Mike. I have a couple of other bikes as well. My '86 Yamaha FJ1200 is pretty cool. A super bike in its day. Glad the vids have helped you out.👍

[@AntonioClaudioMichael]

Nice work on the diagnostics glen

[@ozzstars_cars]

Thanks 👍

[@imadjawad4408]

Great content! thanks for your time

[@ozzstars_cars]

You're welcome! -Glen

[@SmittySmithsonite]

Loved the bonus footage, LOL! Never know what you'll find under the hood these days! That was a riot!! Nice work as usual. Guess it's that time of the year already. If I could do A/C stuff all day, every day, I'd be pretty content. I don't mind that kind of work at all. Nice you had a cameraman! I need to get me one of those, hahaha! Have a great week, Glen!

[@ozzstars_cars]

It was crazy how Kermit blew himself up like a balloon! Always nice having a good helper.

[@SmittySmithsonite]

@@ozzstars_cars - Yeah that was funny! Must be some defense mechanism, like how a puffer fish puffs itself up huge.

[@robertomijango6207]

great video thank for you time and explaint clearly

[@ozzstars_cars]

You're welcome Roberto

[@shahzadgigi]

very helfull. thanks mate

[@georgy4723]

Thank , great video👍☺

[@MrTimdtoolman1]

Great tutorial, good work. You would be my mechanic if I lived close enough to you, and I would not be considering buying an Autel scan tool. LOL!!!

[@ozzstars_cars]

Thanks

[@AntonioClaudioMichael]

Nice scope I like that

[@markrussell9719]

Great video just subscribed 👍

[@ozzstars_cars]

Awesome Mark, thanks!

[@SamirAboushamley]

Thank you so much ❤

[@ozzstars_cars]

You're very welcome Samir!

[@engcolon]

Thanks 🙏 master❤

[@AntonioClaudioMichael]

The frog is so cute at the end

[@BackCountryWrenching]

That’s a awesome scanner

[@ozzstars_cars]

Sure is. Enjoyed the live stream last night Jerry. I may have to try it sometime.

[@JOSERGMMXX]

great video 👌

[@ozzstars_cars]

Thanks!

[@AntonioClaudioMichael]

Yep diagnostics getting more and more involved on vehicles these days can be a pain. Just to fix ac

[@ryanmacewen511]

Dude! Great video. I've been pulling my hair out trying to diagnose my AC on 2008 A6. VCDS was showing an error for refrigerant too high. I had a reading of 32-33 bar, which is a crazy 450psi. Manifold gauges were 63 on the low, and high. I couldn't get more refrigerant in, without getting compressor to cycle. Applying compressed air to middle port, just over 100psi would allow compressor to run. Also running a duty cycle test of compressor solenoid, did actually cycle on compressor at a low rate. Pulling my hair out. I found your video searching for 'G395'. Spent all day futzing around on this. I think I'll just score a new sensor. Found a few on Amzn with mixed reviews. Did the Amazon one actually work!? Thinking $45 at FCP Euro. Tools I have, VCDS, Gauges, VOM, Power Probe IV. Filling system at idle I could not get LO over 63 psi, and Hi was stuck at same. Still wondering if R134a cans are at 63 PSI, and how to fill higher without aid of AC compressor pulling LO side down.

[@ozzstars_cars]

Almost impossible to diagnose that over the internet. You could try a reputable Amazon cheapo sensor and play parts swap-a-roo and see if it corrects the issue but it's a gamble at best. Let us know how you fixed the problem.

[@ryanmacewen511]

@@ozzstars_cars TRUE! I know. After some reflection I decided to order two of the sensors last night. I found some for $30 from FCP that were made in Germany. Its a starting point at least. I'm determined to learn this system, since I have three 2005-2008 A6 cars. So, it seams compressor works, it's getting it told to cycle, is the wall I'm hitting. 4 seasons makes a little tool to cycle it on, but it's like $280, and I think needs to plug directly to compressor.

[@MechanicTechnicianRepair]

exselentes dianostic maeter mui bueno

[@coycarlson4979]

Excellent demonstration of troubleshooting the vehicle a/c with the diagnostic scanner . If one knows how to use the scanner when making repairs - sure saves time. That being said , I believe the scanner you were using is bi- directional - so wanted to know , can you actively test or power the compressor on directly with the scanner ( component test ) to prove the a/c clutch works ? and also prove your a/c system has pressure - taking the guesswork if you're system leaked refrigerant because you do not have a refrigerant gauge manifold to connect and check pressures.Again, thanks for the excellent demonstration ✌️

[@ozzstars_cars]

Yes Coy I have had good success with this scan tool bidirectionally controlling the a/c compressor clutch on many different makes. I have a video review on the Autel MS906BT which has been an awesome diagnostic tool for me. Thanks for the comment!

[@iceboxco3308]

i love the video and the effort you put on explaining each detail, well done and appreciate this. will def like and subscribe. i have a quick question, i am having the same issue with my b8 a4 and same error code 00256. what would happen if i only change the sensor without all these diagnostic procedure you done, would it still work for me ?

[@ozzstars_cars]

Fire the ol' parts cannon. Sometimes ya hit the target and sometimes ya miss. I prefer to test and not guess.👍

[@oladapoaloba]

Kermit the frog 😂😂😂😂 come on geeza!!! 😂😂😂 Nice vid thanks for sharing 😂👍

[@ozzstars_cars]

Thanks for the comment! 🐸

[@enriquemartinez7990]

Thank you very much awesome video I have a 2017 Chrysler 200 with Permanent code p0128 It doesn’t wanna clear no matter what I do drain the coolant replace thermostat housing with calling temperature sensor but the problem is when I go to fill it up with Colin Ronit the fan kicks on every time every time I start the car fan kicks on on low speed I don’t know what the problem is can you help me out please everything is off the AC S off defroster Essaw but the fan store runs on lowest speed all the time but I notice the AC compressor is running to all the time what should I do ?👀🌿. I don’t know what to do the temperature stays on 224

[@maysautomotiveshop1463]

Sir, I have a question, you mentioned the 8 volts ref was coming in from the ECM to the switch vs the 8 volts are being pushed out from the sensor to the ECM. Is this what I’m hearing? If not, my apologies.

[@ozzstars_cars]

Nope. You need an oscilloscope. 8 volts is what a voltmeter sees not accurate for a proper diagnosis.

[@98audiquattro]

Great video, just wandering your thoughts on ross tech vs a scan tool like the autel used in your video. What would you recommend best?

[@ozzstars_cars]

I am not familiar with Ross Tech. Sorry couldn't tell you. I am very satisfied with all of my Autel scan tools.

[@98audiquattro]

@@ozzstars_cars Thank you.

[@flyin4food931]

I have a 2016 VW Touareg. The a/c will stop blowing any air after about an hour of driving above 70mph. I works perfect all around town, in traffic, or under 70mph on the highway. It seems like the mix door goes closes and zero airflow comes out of the vents.The blower fan is running and loud when placed on high but still no airflow. If we stop and turn off the car and wait 15 mins it works great again until over 70mph and then shuts down again. I've had it to VW 3 times with no luck. Any ideas? Maybe a pressure switch of some kind. It shows no error codes. Thanks Max

[@ozzstars_cars]

Is the evaporator icing up and freezing?

[@mikemaifeld6280]

Is the Schrader valve the same size on the high-pressure side as it is the low side side

[@ozzstars_cars]

Sorry I don't know. Never paid attention to it.

[@avtoelektrik_volgograd]

👍

[@stevenlaubach7222]

What happens if I do not purchase the updates on this unit, will it not work or just not have the current updates? I am looking at it for just home use with four cars and I cant see paying for updates yearly or whatever?

[@ozzstars_cars]

The scan tool will work on vehicles up to the last time it was updated. It no longer will have the latest car info and no warranty.

[@mikemaifeld6280]

have you ever changed a R12 system to a 134a I want to do that. Having a hard time finding a coupler adapter for the High pressure line . I bought 4 that were supposed to fit but don't .

[@ozzstars_cars]

It's expensive and a lot of work. Pretty much all of the major a/c components are supposed to be switched to R134. I still have some R-12. 😉

[@mikemaifeld6280]

R12 to 134a Is there a Half Assed way I can do it and save some money haha.

[@inoahmann7542]

@@mikemaifeld6280 You'll have to drain the compressor oil and replace it with PAG, pull a vacuum, and charge it with r134a. Why use an adapter on the high side? Just use r12 guages. Also r152a will work better and you don't have the change the compressor oil.

[@mikemaifeld6280]

@@inoahmann7542 your right I got it thank you

[@CenobiteBeldar]

Does Autel make scanners that tell you the problem accurately for people with no background training in automotive? I'd like to buy one, but I hear their customer service isn't really good. I won't know how to read fuel trim levels and what they mean. Are there instructions provided or does Autel just pinpoint the closest area to the problem?

[@ozzstars_cars]

The tool only provides data which has to be interrupted by the user.

[@carlosperaltacontrerasthe1955]

Comentary to mechanical ( correctly to maxis to scaner)or autel scanner.) To detecting to precion sensor or expansion. Trouble shutting

[@brainwashed7244]

will it do misfire counters or cylinder contributions? on all makes?

[@ozzstars_cars]

No scan tool will do that on all makes.

[@quinnhall24]

Good vid , how familiar are you with the “MK906BT “ ?

[@ozzstars_cars]

I don't use it. I am in North America

[@quinnhall24]

@@ozzstars_cars I am as well . We use factory scan tools as well as an IM608 and maxisys 908 . So that’s the difference I take it . One is for us and the other is for where ever else in the world I take it

[@ozzstars_cars]

@@quinnhall24 Autel definitely makes a great product that is very universal.

[@peteantognazzi5747]

could you tell me who you bought your 906 from

[@ozzstars_cars]

Link is in the description. 👍

[@bigdredre3725]

I see that you use a micsig scope how do you like it any complaints

[@ozzstars_cars]

Works great for me. Takes a bit of a learning curve to set up but overall easy to use with good detail. I like how it's one unit and touchscreen.

[@CC-xi4yo]

me subscribo

[@ozzstars_cars]

Gracias

[@themechanic6117]

how do you like the micsig ? worth buying ?

[@ozzstars_cars]

I like it a lot. All in one unit and does what it needs to.

[@captainron7904]

14.7 psi at sea level

[@mikemaifeld6280]

Is that your bike what is that a Honda ?

[@ozzstars_cars]

Yes. Honda Shadow Sabre VT1100C2. Great bike, 14k miles on it now.

[@SmittySmithsonite]

@@ozzstars_cars - Nice pipes on her! 🤘

[@ozzstars_cars]

@@SmittySmithsonite they look good but the pipe cracked at the flange under 500 miles and the pricks at Bubs Pipes refused to warranty them. I had a guy tig weld them and he did an awesome job. 13k miles later they never cracked again. No Bubs Pipes for me ever.

[@SmittySmithsonite]

@@ozzstars_cars - Ahh CRAP! Sorry to hear that, but I appreciate the warning. I'll spread the word. They sound like a bunch of crooks.

[@MicsigOscilloscope]

Hi, I would like to send you the code to upgrade automotive function for your oscilloscope. Can you reply my email? I think preset automotive function will be more useful to you.

[@ozzstars_cars]

The issue I have with my Micsig scope is that the wifi function never worked since brand new. My contact information can be found in my profile. [e-mail]

[@MicsigOscilloscope]

@@ozzstars_cars we sent you an email, please check, sir.

[@dextergsdblack6560]

you engine is rattling