C30 accelerator pedal position sensor - yellow wire?

[VolvoRob38]

Hi,

Does anyone know what the yellow wire is for on the accelerator pedal position sensor, cable connector side?

I have been having problems with Reduced engine performance message, car idling at 1500rpm. After using Vida to troubleshoot I have come to the conclusion that the problem lyes somewhere between the pedal sensor cable connector and the CEM, as when checking the CEM yesterday the problem seems to have righted itself. Checking for loose connectors, nothing obvious was found.

I have tested the pedal sensor cable connector as suggested in Vida, with key in position ll and all pins read around the required 12v, accept one. The square end of the plug with a yellow wire attached, reading 5v approx. I am just wondering what this yellow wire is for because this could be where my sensor issue might be. Vida says a reading of 5v is too low.

Also checking my battery (distilled water levels) I see that they are very low, borderline dry. Could this have anything to do with low voltage as the battery is on its last legs by the looks of it.

Thanks