A6 water ingress now sensor fault and ESP coming on

[Chriscopes]

Good afternoon, yesterday I hit about 20cm deep of standing water at 60mph on the M25 which almost brought my 2010 A6 2.7TDI to a stop, the instruments went off momentarily as if the ignition was switched off. The ESP malfunction came on TPMS came on and the glowplug heating symbol came on and stayed on. The car went into limp home mode which was great in all that rain. I got home switched off and restarted. Lights went out so seemed ok. I scanned with ross-tech and have fault codes in the glow plug circuit, ABS brake fault 01314, airbag, 12583424 Powertrain databus, tire pressure 02214 fault code, abs control module 01316, information electronic 03276 fault, 03175 invalid data set. I cleared the codes and went for a drive. After a while they come back on and limp mode again.
Are these modules connected or near each other in the car or could it be a sensor at one of the wheels causing the problems? I hit the water pretty hard and it would be like jetwashing. maybe the water came into the car or a wiring harness unedr car was damaged? Many thanks 37324

[dan2485]

Your scan shows that the Canbus for the power train has issues this why the limp mode is on and the ABS/TPMS and air bag faults are present.

You most likely have a connector issue that is shorting the Can Bus signal out.

EOBD II Error Code: P0641

Fault Location:
Sensor Reference Voltage 'A' - Open Circuit - Intermittent

Possible Cause:
Malfunction Indicator Lamp (MIL) active.

Fuse(s).
Wiring/Connector(s).
Engine Control Module (ECM) harness is open or shorted.
Engine Control Module (ECM) circuit poor electrical connection,
Shorted sensor on 5 volt circuit.
Engine Control Module (ECM).

Your scan does not show the MIL as being active but this most likely will be due to loss of the Can Bus signal.

Check all the connections/plugs in the wheel wells and in the engine bay that are at the level of the water ingress.

The 5F faults can be fixed by doing this process Removing the permanent fault VCDS 03175 "Invalid Data Set" after update MMI 3G High (https://cartechnology.co.uk/showthread.php?tid=14942)

[Chriscopes]

That’s wonderful. Thanks for the time taken. I will check connections when it stops raining. Also thank you for the MMI update error resolution.

[dan2485]

If you cannot find any issues then you need to look at the connection stations (bank of mulitplug connectors for inner to outer wiring looms) in the lower A pillars as they may have sustained water damage due to high pressure water as you said you hit the water at speed.