Car going into Limp mode when accelerating

[wilsonian]

Hello,

 

So we've finished replacing the turbo and reconnected everything back up, The engine seems to run OK while standing and for a few days operated fine. However now the car has an intermittent fault. Some times when the engine is at around 3-3.5krpm we get a flashing glow plug symbol, the EML comes on and the car shudders power is lost (like we've hit a limiter). The first time it did this we couldn't get over 2.5krpm however when it happened again the car will go over 2.5 but starts shuddering at around 3.5krpm.

 

I've put VAG com on it and it's reporting the following faults:

 

Address 01: Engine        Labels: 038-906-019-ASZ.lbl
   Part No: 038 906 019 NJ
   Component: 1,9l R4 EDC G000SG  7331  
   Coding: 00102
   Shop #: WSC 13765  
   VCID: 6CDCC9CA1C884B2103-4B18
   TMBWU46YX74167410     SKZ7Z0G4040882

1 Fault Found:
16705 - Engine Speed Sensor (G28)
            P0321 - 35-10 - Implausible Signal - Intermittent
Readiness: 1 1 0 0 0

 

-------------------------------------------------------------------------------
Address 03: ABS Brakes        Labels: 6R0-907-37x-ASR80.lbl
   Part No SW: 6Q0 907 379 AG    HW: 6Q0 907 379 AG
   Component: MABS 8.0 front  H05 0002  
   Revision: 00000000    Serial number: 00000000000000
   Coding: 0002229
   Shop #: WSC 13765 790 00000
   VCID: 020087725E0CAD51D9-515A

1 Fault Found:
01314 - Engine Control Module
            013 - Check DTC Memory - Intermittent
             Freeze Frame:
                    Fault Status: 00101101
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 9
                    Mileage: 172748 km
                    Time Indication: 0

 

 

Any ideas?

 

 

[coskev]

Engine speed sensor is the crank sensor, have you checked wiring to it?

[wilsonian]

forgive my ignorance but is this the sensor thats above the gear box thats held with a single screw?

[coskev]

It's on the front of the block,gearbox end of block between the gearbox and the oil filter housing quite low down if you are looking from above

[wilsonian]

would it also explain the second fault thats being reported?

[wilsonian]

Ok, so just had the connector off and measured the resistance to the sensor which came up at 465 ohms - the manual states between 450-550 ohms is acceptable. The workshop manual does seem to have much else listed for diagnostics of this fault.

Does anyone have an idea what it could be?

[sepulchrave]

Ok, so just had the connector off and measured the resistance to the sensor which came up at 465 ohms - the manual states between 450-550 ohms is acceptable. The workshop manual does seem to have much else listed for diagnostics of this fault.

Does anyone have an idea what it could be?

 

As stated above it's far more likely to be a wiring loom fault than the sensor itself.

[wilsonian]

When the ignition is on we only seem to be getting around 2.5v on all 3 pins. Does anyone know of a common break area?

[sepulchrave]

When the ignition is on we only seem to be getting around 2.5v on all 3 pins. Does anyone know of a common break area?

 

Yes, the wiring between the ECU and the sensor!

[wilsonian]

Well I know that much, just wondering if it has a common exposed area.

[wilsonian]

Just an update. Thought I'd done this back in January.

 

Replacing the sensor repaired the fault - even though it was testing ok on the resistance checks. Be prepared for a nasty job. We ended up removing the oil cooler and giver us better access and you'll need a 12 sided socket - I think 9mm.