2003 S3 - BAM engine
16497 - Intake Air Temp G42 - signal too high
Ok, so this has been running a couple of weeks now. The ECU threw the code up and as a result, the car has lost power, intermittent boost problems and runs lumpy on idle.
I have sourced a brand new sensor from Audi, and replaced. Cleared the code, turned the ignition and the fault came straight back. I believe this fault has to show on 3 separate startups to show an Engine light on the dash (which it does).
Anyway, I scoured the net and found a couple of walkthroughs/guides as to the symptoms, causes and possible cures of the said fault. Both of them suggested that there should be 5 volts DC across the 2 connector plug terminals with the ignition on. I tested, and found nothing, zero volts. I gather that if the ECU sees the high or low voltage limit it will throw the fault. So, convinced I had a wiring fault somewhere, I set about finding it.
Stripped back the loom running under the battery tray and air box, traced the cable back as far as the loop near the pollen filter. I wanted to chase it back to the ECU, but the passenger wiper blade is jammed on the spline and Im having trouble removing it. I cut the cable at the loop, and tested voltage from te ECU - still nothing. (the cable back to the sensor is clear, and has good continuity).
I'm at the stage now where Im banging my head against the wall. Am I actually chasing a lost cause towards the ECU, or is some other sensor/signal somewhere causing the fault (ie MAF or MAP). I have removed the MAF and cleaned as per the guides on here, being very careful with it. No other faults showing on the diagnostic at all, only 16497.
To add to it all, I registered on ERWIN for an hour an pulled up the wiring diagrams, only to find the actual pictures weren't showing (using IE8). Does anyone know if the sensor cable routes directly to the ECU, or does it go via any connectors ? Maybe one has unseated or has a bad pin. I don't know.
I've chucked a lot of time and money at it so far, and I haven't got a pot left to pee in. Can't afford to be throwing new sensors at it without valid reason.
Any help from you guys is greatly appreciated. You will make a jaded (and very tired) Audi lover very happy.