2013 Audi A1 1.6 TDI - Only starts after codes have been reset

[jimincolerne]

Any idea's,

my daughter was driving her Audi A1 1.6TDI, when the Glow Plug, ESP and EML lights came on. She pulled over and switched off, tried to restart, it would turn but not fire.

AA came out and recorded the following faults and reset codes. Car started and ran ok, Turned it off and it will not restart until the codes are reset again. Car driven home seemed ok.

Happen a second time so AA recovered car to dealer, a non Audi garage under warranty,

We have recovered your vehicle. Patrol found the following fault code/s:
System :

Engine control 1 - 7C3 / Diesel EDC Simos PCR 2

P064200 - Sensor reference voltage A. Error Message : Signal too low.

P023600 - Boost pressure sensor. Error Message : Signal improbable.

P040700 - Exhaust recirc. position sensor. Error Message : Signal too low.

P033500 - Crankshaft position sensor. Error Message : Faulty operation.

P034100 - Camshaft position sensor 1. Error Message : Signal improbable.

P15A200 - Neutral position sensor. Error Message : Short to ground.


so wanted a little knowledge, so that I know when I'm being fobbed off by them.

any idea's regards James

[Crasher]

Why do you assume they will fob you off, have they messed you around before?

Those fault codes obviously indicate an electrical fault, I can’t check at home but I imagine all those sensors share the same 5v voltage supply line from the ECU. The fault could be with the ECU itslef (highly unusual but it does happen), a wiring fault (still unusual at that age) or one of the sensors having gone short circuit inside and causing the feedback from the other sensors on the same circuit to be “implausible” and I have seen this many times with the Manifold Pressure Sensor (MAP), a look at the wiring diagram would be very informative but I can’t do that until Wednesday. Also, the CAXA engine EGR unit is extremely prone to problems, even non genuine replacement units can fail instantly and cause wiring shorts. The standard way to deal with this is to unplug the affected units one at a time and see how the stored codes behave, I would go for the MAP first and then the EGR valve but that has to be accessed with the car right up in the air from below.

Recently I had an Audi TTRS that needed a new ECU as the supplementary water pump seized and burnt out a number of tracks in the ECU, it is a silly idea powering a water pump that way and your daughters car has two.....