2012 Passat B7 1.6 TDI Electrical issues

[Twolitrepinto]

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[Twolitrepinto]

If you find a used ECU with the exact matching part number (what is the VIN and the numbers off the other ECU’s) I can usually rematch a used ECU with ODIS. If not I know a man who can but he is in Derby and may not travel as far as Lincoln. He is coming to do an ECU mod on an A4 for me next week so I will ask him. At the moment I don’t have ODIS as the Wi-Fi board on my Dell laptop did something to its driver and Dell drivers are apparently unique so I am waiting for its return.

Hi again.

So I managed to adapt a used ECU to the car successfully. it started and ran with 1 or 2 small faults but nothing too bad.
Then 5 minutes later, I shorted it to positive while refitting it and popped it!

Since then, I adapted another ECU, but it had all sorts of communication errors, so I returned it.

The car now doesn't run at all, and I'm completely fed up with getting nowhere myself with it.
I don't want to keep buying ECU's, and paying for use of ODIS with no way of knowing if it will work.

If you know anyone that can come here and help me with this, I would appreciate it very much.

Thanks

[mickeybo]

The 3 ecu earths (grounds) on this vehicle are ecu pin nos a1-a2-a4 if any 1 0f these are faulty then your ecu cannot function properly

[Twolitrepinto]

The 3 ecu earths (grounds) on this vehicle are ecu pin nos a1-a2-a4 if any 1 0f these are faulty then your ecu cannot function properly

Thanks.
I will test those out on the one I shorted out as I can't see anything physically wrong with it, but I'm no electronics expert.

[Twolitrepinto]

So I tested these pins and they all have continuity to ground.
I also tested the main ignition live pins to the ECU and they are all powering up suggesting that the relay is OK.

The original water damaged ECU has part number 03L907425C / 03L907425C HW43.
I have been purchasing replacements with these same part numbers.
One came from a Touran, One from a Caddy, but all same numbers with differing results.

I read somewhere that this part number could just be a generic part number, so it may have been replaced before and flashed?

Today, I put the original water damaged ECU back on the car, and loaded into ODIS to do ECU identification.

ODIS shows the ECU as 03L906023FS / 03L907425C H43.

When I look into buying ECU's with this part number, they all seem to be from a Passat.

What are the 2 different part numbers as most seem to have the 03L907425C on them as a secondary part number?


Thanks in advance.

[Crasher]

The replacement part number for your ECU is 03L 906 023 FS 360, 03L 907 425 C doesn't come up in ETKA so is an internal use number in which case the original ECU needs a code read to get its proper part number. 03L 906 023 PA changed to 03L 906 023 TB and is for a Caddy CAYE engine.

[Twolitrepinto]

Thanks for the reply.
03L906023FS is what it comes up as in ODIS.
I'm guessing the 03L907425C is a generic number for a replacement which needs to be flashed with whatever software, which would explain why i've had mixed results using ECU's with this part number.
Not sure where you got the 03L906023PA from?

Anyway, the only one close I could find was 03L906023MM which i'm going to try to adapt once it arrives.
It's for a Golf with the CAYC engine. Fingers crossed it will adapt. Then hopefully I'll be able to flash it with the 03L906023FS firmware.
Failing that, i might get someone to bench remap it with egr and dpf off and flash using the other file as a base for the remap

Thanks again.
Completely agree with your comment about climate change and religion btw

[Crasher]

I am no tree hugging enviromentalist [sic] but I fiercely oppose removing legally mandated exhaust emissions equipment such as EGR and DPF, we all deserve to breathe clean air. If we get a car in and we find it has had anything like this done, we refuse to do ANY work on it until we have reinstated the missing systems.

[Twolitrepinto]

Fair enough. Just to clarify, I have not removed any part of the emission system. I just thought that If i had to get someone to flash it, that I would save myself some future headaches, but point taken.
Anyway, the replacement ECU did indeed adapt successfully and it now runs, although I can't flash it as i don't have a cable that works with Odis-E.
I still have the P0123 code so I decided to replace the throttle body / valve with a known good used one but this code still remains.
The part number of the replacement was 03L128063AD
I did as the odis-s guided diagnostic said and tested for shorts to ground and b+ on the connector and all was OK there but the voltage does seem to fluctuate from 4.5 to 8v on that wire (5pin plug at throttle body).
It isn't the ECU as it's had about 4 different ones on it now and this fault carried across to all of them.
Any common problem areas to check or is it likely just another faulty TB?
I can't run the function to adapt injector minimum quantity deviation as there is a permanent fault code present. I feel it needs it sounds rough (diesel knock) which it didn't before.
I did put all the injector codes in already.

Thanks again for your help.

[Crasher]

Remind me tomorrow with the VIN