How To Diagnose A Faulty ECU With No Communication

No start of the vehicle and no direct communications to the engine management system – ECU fault right? Or could it be something else?
Let’s ask Tim…

[edthompson]

Man what an informative yet clear dissemination of ECM testing. I am much more cognizant of what is going on with the ecm in my vehicle .

[brianchigwenembe]

Never have had a well tutorial explanation as this one . Great thanks

[chrismac]

Great video and explanation. I tested my EUC that came with a swap kit for "crank but no start" with your information. After verifying all good grounds, constant 12v, and switched 12v, my EUC failed to pull the constant 12v to ground, allowing the relay to receive a negative signal and switch the relay on and provide power to the other side for boot up.

[danielesquivel]

Using this video I found a problem with the ECU cable system that five previous mechanics could not find. Turned out to be a problem with the wire between the main relay and the fuse (the yellow lines at 4:05). Thanks a million :D

[kakongebryans]

Thanks very much for this well articulated video, am having the same issue with my Audi Q5 2010 ECU is burnt, am wondering the +be line was not fussed?

[train]

A superb video sir, very helpfull.thankyou.steve from the uk.

[khurrammalik]

Thank you for a good through and simple explanation. Nice Work

[robertkoza]

Incredibly thorough. Great video. Thank you.

[coulioouagninnin]

Merci très bien expliqué.
Du Courage.👍

[nickayivor]

Thank you very much helpful video 👍
From Nick Ayivor from London England UK 🇬🇧

[aritrasinghachowdhury]

Hi, Very nicely explained. Can u pls. advise how various ics of ecu with pinout designation ( eg, Power ic etc) be identified ? Any book or website will be a great help.

[pegasusfly]

Have a suzuki xl7 that runs great when it's cold but once it been running. That's when I have issues. The speedometer sometimes works, the thermostat started running hot. The engine isn't hot at all. No leaks in the radiator. The engine light has come on, now it doesn't come on. The traction control light came on. Now it doesn't. It shifts hard, slipping, Complete stop then shift hards when going to complete stop. Sometimes it doesn't want to go into gear. Drives great when its cold. Any suggestions?

[francisdsa]

Well explained with diagrams and meters to test appreciate and thanks for the efforts.👌👍

[laxonetrc]

Very Good explanation, Thank You, Subbed

[DanielSmith-jlin]

This is very helpful as i am experiencing code po600 no communication can high on my 2005 volvo xc90. I will start with the main relay. Thanks

[SRSpoony]

Hi Tim, i have a ford S max that wont let me clear codes and is limiting power while driiving like 2200rpm and then nothing turbo working drives fine unless you put your foot down and its like its in limp home mode but i can get on the motorway and do 80mph just takes forever.

any ideas ?

2008 2.0 tdci titanium. its like its bricked when you lock your mobile with the wrong code in it, turns up but its not doing much. how do i find which version of ECU i have to get 1 from you or send mine back to check it.

[oladelesanni]

Please can you advise as AA diagnosed my bmw e90 as no communication between ecu and engine but when ignition is on the fuel tank pump continues to run for a long time and also the starter

[rustys]

Excellent: really high quality info, thank you 👍

[daviddo]

I was wondering if a weak battery could also set code only because in the morning it seems like it has a weak cell in the battery that’s when it went off check engine light and then it starts right up afterwards easily when it’s been running

[tof]

Great video I learned a considerable amount from watching this one video (now subscribed)
I have a Maxicue OBD reader and it has thrown up this fault
Audi A3 (8P)
Convenience system (TP)
01320 intermittent Climate control no communication
00352 intermittent terminal 30a open circuit
0095 intermittent Key 1; adaption limit exceeded Faulty or no basic setting/adaption
01565 Permanent Luggage space lighting Short circuit to ground

>
The 01565 may now shed some light (sorry about the pun) about the parasitic drain that I could not find.
But anyway the car is still driveable.
I look forward to your response
Tony