Manifold Pressure / Boost Sensor (G31)

Hi all,

I am writing this up on here for future reference in case this happens to anyone else.

Car is a 2008 Octavia Scout TDi PD 140 (BMM).

At the weekend I carried out a service on the car - oil, filter, fuel filter, air filter and cabin filter. On putting everything back together and starting the car up I got a flashing coil light on the dash and limp mode. In something of a panic I got out VCDS and scanned the car which came back as follows:

Address 01: Engine Labels: 03G-906-021-BMM.clb

Part No SW: 03G 906 021 SS HW: 03G 906 021 AB

Component: R4 2,0L EDC G000SG 1302

Revision: --H08--- Serial number: SKZ7Z0H4763111

Coding: 0000172

Shop #: WSC 73430 000 00000

VCID: 820F4DABDD7E6108B6F

1 Fault Found:

000568 - Manifold Pressure / Boost Sensor (G31)

P0238 - 000 - Signal too High - MIL ON

Freeze Frame:

Fault Status: 11100000

Fault Priority: 1

Fault Frequency: 1

Time Indication: 0

Freeze Frame:

RPM: 0 /min

Speed: 0.0 km/h

Load: 0.0 %

Voltage: 12.01 V

Bin. Bits: 00101100

Absolute Pres.: 183.6 mbar

Absolute Pres.: 2182.8 mbar

Readiness: 0 0 0 0 0

After searching on Briskoda for a possible answer I learned that it was likely to have something to do with the MAP sensor, so I went back to the car and started looking for the MAP sensor (Under the air box I believe) and what I might have dislodged around where I was working.

Whilst looking for the MAP sensor I discovered a thin black wire emanating from under the air box and traveling across the front of the engine to the off side front of the engine bay where there is a sensor on a large diameter tube from one of the radiators (I assume this is to do with the intercooler). At this point a lilac wire breaks out of the loom to this sensor and the black wire is scotch locked to it and labelled something to the effect of "Pin 5 MAP sensor"?

What I found was that water had at some point got into the scotch lock connector and the lilac wire had more or less rotted through. I had finished the job of breaking this wire whilst stuffing rags around the fuel filter housing to catch spillages whilst changing the filter.

So, soldering iron out, wire repaired and wrapped up against liquid incursion and success, no more dash lights and full power restored. Car seems to be running smoother and quieter now as well, but this might just be my imagination or as a result of the service, anyway I was very relieved.

Judging by the green colour of the exposed wire and scotch lock connector this had been on its way for some time and was just finished off by me disturbing it.

So there it is, on the record in case anyone else suffers a similar fate at any point.