Flashing Coil symbol on Dash - Not EGR...

[Tigggrrr]

2009 VW Passat B6 190k miles
Recently engine fault appeared above. Appears to reset at end of journey and doesn't always come on in journeys up to an 45 minutes long.
Can go into limp mode shortly after coil symbol going on. Tried cleaning EGR valve which has been done once before many years ago as it was badly carboned up.

EGR valve doesn't seem to open when testing with VCDS but if you put on 12v across EGR it opens fully. Tested with a new replacement EGR same problem with Valve barely moving. Guessing maybe problem with wiring to EGR or ECU??? ECU seems to be a nightmare to get to. Eventually got wiper blades off but rain shroud seems fixed below windscreen. Have removed clips at front I can bend shroud upwards to see ECU. But can't really access it as I can only see front bolts.
Anthing else I should be testing? Or tips on how to remove shroud, test wiring to EGR. Thanks for any help.

[Tigggrrr]

Managed to pry open the shroud and undo 2 bolts holding a square plastic cover over the ECU. There is a metal frame clamping the ECU. Plugs at the front which I can't seem to remove. It looks like it bolts into captive nuts either side but the tops don't seem to have anything to drive them???

[DMitch16]

Managed to pry open the shroud and undo 2 bolts holding a square plastic cover over the ECU. There is a metal frame clamping the ECU. Plugs at the front which I can't seem to remove. It looks like it bolts into captive nuts either side but the tops don't seem to have anything to drive them???

Should be similar to the Golf. The ECUs are held in a rigid frame usually with a spring locking clip. It can be a wrestling match to get it free of the frame, just be careful with the wiring which may be a bit stiff after 12 years. I don't believe they are bolted in and once the spring clip is released the ECU slides out to enable the loom connectors to be removed (they have plastic locking mechanisms and once released the looms unplug).

Removal process based on a CC here:
http://www.goapr.co.uk/support/ecu_removal/cc_3c8.html

[Tigggrrr]

ECU sent to ECU Testing, sadly they have just come back and said they are unable to test it and recommend trying another company. Any suggestions of reputable companies?

[DMitch16]

ECU sent to ECU Testing, sadly they have just come back and said they are unable to test it and recommend trying another company. Any suggestions of reputable companies?

Did you have the car scanned for fault codes before you pulled the ECU? That would have been my first step.
Then to do a visual inspect tracing the wiring back to see if any pinch or rub points along the way and checking any grounds associated with that circuit.
Next would have been to find a circuit diagram for the EGR circuit back to the fuse box etc.
Then check the wiring for power, ground etc. at the end connector to the EGR.
Thereafter tracing back and isolating sections of the circuit to test them individually until you find the problem. Seen it done many, many times but not had to do it yet myself as my last short was a visibly burnt loom and pretty damn obvious.
Usually ECU faults on these cars are fairly rare, but not unknown although I am not in the trade so stand to be corrected if not the case.

[Crasher]

ECU sent to ECU Testing, sadly they have just come back and said they are unable to test it and recommend trying another company. Any suggestions of reputable companies?

Not them that’s for sure. You could try BBA Reman, ACTronics or even Bosch themselves in Germany but ALL the above have let me down time and time again to the point if one told me the sky was blue I would go and check.

Bosch in Germany sent me the picture below of a TTRS board that no one else could test



This was the second time I sent it to them at hundreds of pounds a time plus dead car for two weeks each time. The second time they said “yah, is egfickt” I said can you fix it? “Nine, ve can send you nu von for €2000”, which was more than genuine from TPS!