How to test a computer controlled solenoid - power/ground side identification

[@billrimmer5596]

I go back and watch these videos and get enlightened all over again!! Thank u!!

[@danielgreenbaum8875]

So true am watching this 4 yrs later and it makes so more much sense as ive put scanner ideas into my diagnosis

[@KASAD0]

There is no better video than this video explaining how to identify power and ground side switched circuits and how to test them and what is good , what is bad , ❤❤👍👍👍 thank you

[@johnny0454]

Thank you. You are genuinely doing a great public service just by being yourself, fantastic work my friend!

[@baxrok2.]

I've watched this three times. However, it never really made total sense and became clear until I watched your short tutorial with ETCG on PS/GS side switched circuits. Thanks so much for all of your work.

[@ScannerDanner]

+Baxrok2 thank you!

[@justjoej]

This is hands down the BEST automotive repair video I've ever watched. Completely electrically inept, and I learned a lot. Thank you!

[@ScannerDanner]

+Joseph Julicher thanks Joseph! I really appreciate your kind words.

[@ozzstars_cars]

You made power and ground side switching explanation so clear and precise it's like magic Paul. I'm serious....great video once again! Last week I diagnosed a defective EVAP canister purge solenoid on my 4th gen Corvette. I bench tested it and found mini bits of charcoal inside the solenoid...it 'froze' stuck and would not open. Hoping I can edit the video soon and post it to help others. Turns out the charcoal canister internally failed and engine vacuum sucked the charcoal into the solenoid when it opened. Crazy I had never seen this before. The symptoms of a clogged vacuum tube/solenoid not working...extreme fuel vapor pressure when removing the gas cap! Never had a trouble code...1993 model OBD 1.

[@jarinwilson9539]

High side vs. Low Side drivers.....love it Paul

[@billrimmer5596]

So in this video, we learn about bidirectional control of a circuit. We also learn about using a DVM for a jumper/ammeter. Scan tool, both types of test lights, DVM and t-pins. Wow! Thank u Paul!!

[@ScannerDanner]

Thank you Bill!

[@mikembz1]

Paul i learned more in 22.32 minutes than entire semester in school.

[@MaicSalazarDiagnostics]

Great video Paul!! I have learn a lot of new diagnosis strategies with your videos, God bless you! By the way I have acquire the Verus Pro! Awesome tool!! follow all your Verus videos as well, I feel very confortable with the Verus, like a pro now!! Thanks a lot!!

[@ScannerDannerPremium]

That's great Maic! Thank you too!

[@SouthMainAuto]

Hey Paul, Great teaching and I hope the young men and women in your class know the value of your knowledge you share with them. You provide excellent and clear instruction. On the purge solenoid you were testing, if it did not have an accessible vacuum port would it have been worth having the students look at upstream 02's and STFT while you activated it to look for a rich change to verify operation? Sure would love to sit in on your classes. Keep up the great work! ---Eric O. S.M.A.

[@MikeMotto]

I bought the subscription to ScannerDanner premium channel I am not sorry that i did. you are in the classroom while he teaches. Highly recommended. of course South Main Auto Repair ain't too shabby either!

[@buzzfry1960]

Love the information I get from mr danner I've never been a scope type of guy and I have actually owned an old snap on vantage but it sat in my toolbox so I traded it for something Elise . Now I've got a Autel ms906ts scanner but I'm not sold on the scope you can buy for it so I have bought a nice used versus and I can't wait to tear into my 03 eclipse just to watch the sensors work . Looking to go on my own again part time for this kind of work . I see these electoral shops charge a fortune just to fix simple and of course not so simple stuff . I am definitely going to stick my fingers in that piece of pie and get me some a few months down the road .

[@halwesth0]

Thanks for every single info you share with us you are amazing paul thank you 💓

[@whitetiger8652]

Always good to revisit a subject such as this. Thanks

[@acrittendoncrittendon4143]

Grate seeing it and reading it makes learning better. Thanks

[@nickayivor8432]

PRODIGY Sir ScannerDanner My teacher God bless you and all your family around you Sir ScannerDanner for sharing what you know with us Thank you very much Take care and have a great day My teacher PRODIGY Sir ScannerDanner From Nick Ayivor from London England UK 🇬🇧

[@careyautorepairs]

Another fantastic video Paul.

[@rrmech11]

Its always nice seeing your diagnosis

[@adilmchichou5710]

I watch this video 3years ago and I still remember everything

[@Geekdiymechanic]

Excellent video, as usual. Great content and demonstrations.

[@arkadiuszantczak7918]

good job the attention to detail i have been on many training courses but you exactly do you explain the thinking for diagnosis . I am a mechanic and automotive electronics for 18 years but draw your films as Tarantino movies hehe .

[@joshyjosh111]

You inspire me to go back to college

[@johnwrench4speed]

Great video. On the A/C circuit, I believe, w/out having a wiring diagram, the pcm controls a relay in the PDC (power distribution center) sending power to the A/C clutch. So even though the A/C is power side controlled at the clutch, the pcm controls the relay on the ground side.

[@ScannerDannerPremium]

That is correct but the concept is the same as far as circuit ID and testing on a power side switched circuit. It even shows that this concept can be used on a non computer controlled switching circuit.

[@deuceelec]

How to determine which Computer connected components can be tested with the incandescent light and which require the "computer safe" LED light? Superb video, thank you.

[@ScannerDanner]

The "computer safe" LED test lights will get you in trouble more than help you. (misdiagnosis of circuits) Just make sure you know what your test light current draw is. The one I use you can find on my website on the tools page. www.jbtoolsales.com/otc-3633-mini-circuit-tester#oid=1014_1 It draws about 180 - 200 ma of current and is good for testing most output circuits. When would I suggest an LED test light? For stepper motor circuits and base circuit control or triggering of a transistor. Thanks for watching and great question!

[@nemanjadzombic6101]

Thank you for another perfect video!!!

[@Caradonia]

Great video! Well illustrated.. Thanks! ;-)

[@junioralvarez1103]

tnk broth to show us easy way to check for pawer or ground computer control i like it

[@lloydlawson2186]

Yeah you pretty good Mr. Danner!

[@northernpatriot9078]

hi paul how would you know that five volts is a bias voltage I first saw that and thought problem or high resistance in wire lol am i stupid

[@michaelcortes4331]

I noticed you checked the computer driver with the Solenoid unplugged with the test light.can you also test the pcm driver with the solenoid plugged in ?

[@ScannerDanner]

Yes, but if the solenoid is shorted you can get misleading results.

[@wtbm123]

Good video.

[@carlosfavela9616]

good lord your videos danner I like the scanner you use where it could get one of those'm from mexico and I do not lose any of your videos I have a workshop and I work'll fix elctronicos problems until today pond in me to become well my travajo an served me well your videos

[@spelunkerd]

I sure like the way you use your the ammeter side of your multimeter as a jumper set, after verifying circuit design. Not only do you get instant amperage readings, you also have a fuse inside the ammeter to hopefully protect the circuit if you make a mistake. I can't say how many times I've fried the ammeter side of various meters, every time slapping myself in the forehead like Mo in the three stooges. It hasn't happened in the last decade, but surely it will happen again one day. So far, touch wood, I haven't yet fried a PCM....

[@abderrahmanegouasmi7556]

Hi Danner, I was testing the vacuum regulating valve (for turbo actuator). It is supposed to show pulse curve , a kind of square voltage at both ends. With my scope, I see just a line of 12 v max witout up and down. Is the ecm itself who supply the pulse curve or it is the electrovalve. What do you think please. The car is Toyota avensis.thank you.

[@glenohara6563]

You say that a test light has to be used with a faulty or open coil, would you be able to put the scope positive lead to battery and earth lead to control wire? For earth switching.

[@spartan1071]

I had a jeep just like that in my shop not that long ago and the air box was cracked on top of the throttle body which looks like that one is as well. It caused some running issues and a dtc.

[@vencentbauer]

so Paul if I went on my pulse with on my modus ultra and used my other scanner for bi directional control it should work just fine for power side and ground side switches

[@ScannerDanner]

I would use a voltage scale, not the graphed pulse width. You want to see amplitude of these signals and the signature of the waveform.

[@vencentbauer]

thanks Paul keep up the great videos

[@Hector-444]

Is it normal if my purge valve only ticks sometimes, even if the engine is hot? Does it have to tick consistently?

[@vencentbauer]

your best video danner u look like me scanner hooked in modus ultra vantage pro and meter and wires everywhere I get nervous when people ask if tgey should start car lmao check for wires lol

[@eduardofelix2906]

you are the BEST ....

[@bbmd2200]

Thank you, Mr Paul, for your great teachings. Just to confirm, In a power side switched solenoid, the output state monitor wants to see 0v with driver off and 12v with driver on and in a ground side switched, the output state monitor wants to see 12v with the driver off and 0v with the driver on ? Plese a simple yes or no answer is good enough for me.

[@ScannerDanner]

Yes sir

[@bbmd2200]

Thank you so much, Sir. Happy new year!

[@edgarcastaneda9086]

Hola Mr. Danner, great video as always love them all, my question is while doing these test does the key has to be on all the time (KOEO) for the ground side switch? i heard that for the ac clutch it is needed to be running (KOER) if i don't have a scanner saludos from Mexico

[@ScannerDanner]

+Edgar Castañeda it depends on the circuit you are working on, you may need the engine running on some

[@keanuserion8140]

Can an autel control solenoids and stuff like this do you know? Thank you so much for all the info

[@ScannerDanner]

yes, absolutely and this is where the Autel shines is within it's bi-directional control capability

[@AlwaysDiagnoseVehicleFirst]

After connecting the test light to battery positive and touching the t-pin on the control wire on the ground side switched how do i manually check the driver without a scanner where the light flickers on and off the same way as the bidirectional scanner? Cause I don't have a Snap on scanner. Please let me know I will greatly appreciate a response back! 🙏

[@ScannerDanner]

There are two ways: 1) use a bidirectional scan tool to command it on 2) meet the conditions for that driver to turn on (this is no easy task on some drivers) There is no other way. This shows why you NEED a good scan tool

[@AlwaysDiagnoseVehicleFirst]

@@ScannerDanner I'm trying to do option 2 on a 2003 dodge caravan SE how would i meet the conditions for that driver to turn on like what steps do I need to do so i can apply it?

[@ScannerDanner]

@@AlwaysDiagnoseVehicleFirst what driver?

[@AlwaysDiagnoseVehicleFirst]

@@ScannerDanner The driver in the purge solenoid.

[@ScannerDanner]

@@AlwaysDiagnoseVehicleFirst so you need to research when that purge solenoid is active. Read the description and operation of that system and that is your answer. Again, every car is different and every output is different! Typically a purge solenoid is active just after start up.

[@Elchin206]

Hello. Ground side switched solenoid with 3.45V bias. But with the plugged connector, on the one side 12V on the other side 2.80V. If it is shorted to ground then there must be 0. But it is 2.8V. Solenoid is new. Is it the bad ECU?

[@ScannerDanner]

Should be 12 and 12, not 12 and then bias. You have an open right at that connector or the new solenoid

[@Elchin206]

@@ScannerDanner I am measuring 2.8 at the solenoid connector( backprobing as you teaching) and also on the PCM connector. It is the same with known good solenoid. Can the short to ground be "partially"? Or is it the PCM issue?

[@ScannerDanner]

​@Elchin206 doubtful you have a partial short to ground. Tale a test light to battery positive and touch on control wire at solenoid connector (unplugged) and see if it lights. Also measure voltage at the pcm terminal. Tell me what you read with the test light there.

[@Elchin206]

@@ScannerDanner with disconnected PCM? (Section 3 page 17?)

[@Elchin206]

​@@ScannerDannerHi Paul. Connector disconnected, test light on battery positive-test light on. Then I disconnect the PCM - test light off. I measure voltage on PCM pin same 2.80V Bad PCM?

[@markstevens2868]

My 86 ranger 2.3 egr relays rubber attaching holder broke and the two egr relays sounded like lifter noise. Took them all out and couldnt find problem. Got really bad, drove it 1 year not being able to understand. Not a mechanic. Maybe shade tree. Wraped them in foam and brought them off the metal fender. Still dont why they pulse and whats wrong

[@jecrisjohnsaso8323]

Sir if you dont mind, can I ask what brand of digital multimeter are you using? I mean brand and model of that yellow dmm...because I want to buy same like you are using, fluke is very expensive

[@ScannerDanner]

"Ideal" was the name of that meter. I think

[@jecrisjohnsaso8323]

Thank you sir....😊😊

[@rodger6940]

Can someone please help me key on engine off I'm getting 1.79 volts in both sideshow Unplug 1.79 and control side 0.0 im really confuse 07 dodge caliber purge valve p0444 I don't know where to start I'm not getting any voltage from either side is probably the tipm?

[@zebshahab]

why these thumbs down ,i m requesting those who thumbs down can raise a question instead of a thumbs down so we all can learn

[@ScannerDanner]

+shahab alam zeb just haters man

[@mattharris7256]

So will a ground side switched circuit have 12v+ on both sides of the solenoid until the control module toggles the signal wire to ground?

[@ScannerDanner]

Yes, but don't call it a signal, that is a term applied to input circuits. I know I'm picking on a word and it's no big deal, but it is important when learning these concepts to use the correct terminology to prevent confusion when troubleshooting. Make sense? We would simply call this a control wire for an output (which is what a solenoid is, an ouput)

[@boybravo689]

Sir may I know what sensor you are testing for, how many wires that sensor have subscribers from the Philippines tnx Sir

[@8953147]

Does it matter where, in the circuit, you put the AMP meter in order to get the correct reading? I know you put the meter on the NEG side of the circuit. What if you put it on the POS side?

[@armandonika]

Doesnt change anything.

[@franciscovera5980]

baxrock2 I liked to watch that etcg video, what is etcg or put link please its also a little confusing to me. thanks

[@hectorpena2705]

Could this apply also to diesel tractors a 4-cylinder backhoe John Deere

[@ScannerDanner]

Yes, absolutely!

[@sara78130]

hi paul if got test light 6v to 12v can i use it ok ok.or i ned buy 6 /12/24 v thnx

[@ScannerDanner]

+KURDISTAN uk just a 12v test light is fine. 24 if your working on 24 volt systems

[@sara78130]

ok thanks

[@sara78130]

i understand now 100% thnx

[@ScannerDanner]

+KURDISTAN uk no problem! thank you

[@rodger6940]

I use my verus to do the bidirectional but nothing I erase the code and it comes back on in matter of 5 seconds

[@miltonscornertobylove5068]

Awesome!

[@perez7667]

Hey, Paul. Could you energize a ac clutch coil that way?

[@ScannerDanner]

Yes, by jumping thr load side of the relay, which is what the uActivate tool does that I think I was using

[@perez7667]

@@ScannerDanner In this video, you did not use the Uactivate; you used the voltmeter as a jumper wire to energize the solenoid.

[@ScannerDanner]

@@perez7667 then I would have switched the DMM leads to amperage, not voltage. I've done this many times. An ammeter is simply a jumper wire with a gauge on it lol

[@jamesbarratt593]

This power ground side identification business and your book. I have been reading it and find myself confused. My Golf 2.0fsi has high emissions and fails the government tests. OK so I test egr solenoid pins 1 and 5 with connector UNPLUGGED. Both show 12v and I asked you once about this. You’d mentioned one must be bias voltage. So I connected a test light to battery ground and touched both one at a time. Yep the test light lit when I touched both. The flow charts say pin 1 is battery ground and 5 positive though. So I run leads from battery to egr and the thing clicks. I look with inspection camera and the valve does not open though. So I use scan tool and action it with obviously connector reconned and the valve opens. So how come it does not open when my wires were same thickness as the wires in loom? How come the two wires show 12v and will light a test light when connector unplugged?

[@ScannerDanner]

what kind of test light? bet it was an LED type, you need an incandescent light

[@jamesbarratt593]

Nope not an LED for sure. Incandescent from laser tools. Since that I have also found the ECM has a pin broken and others around with green mould or something on them. The broken pin is for12v input from main relay. Guess this is the reason engine computer not operating properly. Did also discover that with the cylinder 2 and 3 misfire I could make it go away for 4 days by removing and recomnecting the ground wire to the electric power steering rack. VW had issued recalls on 66,500 cars because ABS/ESP unit looses ground connection. Fix supposed to be either software update or new ABS module.

[@geojor]

thank you...

[@alyte11]

Ever experience an issue due to unplugging/reconnecting a connector with the KOEO or KOER?

[@ScannerDanner]

As far as damage to a computer? No, never. A solenoid will have higher voltage spikes when the field collapses (when its turned off) than any connector unplugging would create

[@alyte11]

Ok, I didn't think you would do it if there was a chance of something being damaged, computer or otherwise. I only ask because one of my other books says it could "destroy some components depending on various circuit designs". Your response is appreciated!

[@ScannerDanner]

@@alyte11 There are certain circuits where you'd want to be more cautious. Take an airbag module for example. I'm definitely not unplugging one of those with the key on.

[@jb6574]

Would you end up frying the computer if you grounded the power wire instead of the control wire?

[@ScannerDanner]

No but you would blow the fuse. When you get into trouble is when you ground a control wire that is power side switched by the computer or power a control wire that is ground side switched by the computer

[@jb6574]

@@ScannerDanner got it thanks

[@alexmessina3383]

Hi Paul, sorry if I keep saying this, but great vid, again! Question: how were you so certain up front that your incandescent test light would not harm the driver. Was is just general knowledge that that kind of solenoid would need about 300mA to energise? When and what kind of circuit/driver would you NOT use an incandescent test light? Remember the vid where you recommended using a 5K ohm resistor to put power side into a sensor (TPS) ground? How do you judge when it's ok; when not? thanks:-)

[@ScannerDanner]

+Alex Messina All really great questions and too much to answer in print. This is all stuff I cover in class. Would you like a coupon for a free month of my premium channel? This would be Section 3 material

[@mrdboyd44]

what scanner are you using

[@ScannerDanner]

Snap-on Verus

[@GRowe1978]

Does anybody know of an inexpensive scan tool with solenoid functional check capability? I know how to test the solenoids themselves, but I have no way to test the drivers to be sure they're switching on and off.

[@TechBen19]

Hi, sir danner :) can i ask a favor do you have a electrical troubleshooting in c.r.d.i engines? i just want to know sir how you will attack crdi engines sir , Thank's :)

[@luisv528]

Is there any way to test driver without scanner tool?? Great video by the way.

[@ScannerDanner]

+Luis Valenz yes kzbin.info/www/bejne/bnfRip-im5p3b6c

[@luisv528]

+ScannerDanner Thanks for the response.....great videos.

[@northernpatriot9078]

ok i see it is just the way that circuit works by it have the proper voltage plugged in told you that is a bias voltage I just didn't understand the same voltage on both wires but one is a control wire and has bias on it for computer

[@Mcduggies]

I have one of those expensive test light from snap on was like $68 and I absolutely hate it I'm gonna get one with an actual light bulb in it

[@felixcat4346]

That is one puny 12v car battery being dragged down by a small 3 or 5 watt incandescent light bulb.

[@rodger6940]

Can someone please guide me

[@MrUnbekannter111]

So you can say the solenoid works with 7 Volts because the 5 Volts bias on the groundsite....😉

[@steniofernandez824]

I have the premium subscription also then book..it worht it every cent of it...i have payed trainning its nothing compare to this.. highly recommend. .haha just laughed cuz my trainner sayed the only good thing about the test light it u can stab peolpe with it!!

[@franciscovera5980]

just realized, it means eric the car guy