My car: 996 TT, 2001, Tiptronic, stock except for EVOMS diverter valves (installed 15 months ago).

Recently, on 2 occasions, I got the PSM and ABS warning lights and the message 'drive to shop'. BOTH occasions, I was stuck in a traffic jam and a lot of 'stop & go'. Both occasions, it felt like the engine started hunting up and down at idle. Both occasions the problem went away when I shut down and restarted and drove normally (or faster).

I have trawled through a large number of threads on this subject and I have a few questions:

1. Based on WHEN it happens, it looks like it could be the brake light sensor under the pedal. If so, can anyone provide me with a part number and some instructions on how to change it out (bear in mind I am NOT mechanically minded)?

2. Based on the idle fluctiating, might that indicate a different source of the problem? Should I clean my MAF? If so, are there any instructions on how to do that? (Bear in mind I have no idea where the MAF is or what it looks like).

3. I think these are the 2 first things I should try (lowest cost and doable by myself). If those 2 don;t fix the issue, what does the forum think should be the next steps and why:
- Throttle body
- MAF replacement
- Alternator
- ABS wiring harness inspection

I appreciate any and all feedback and apologize for being a mechanical newbie. At least I read up on the issue before asking the questions, LOL

Thanks,
Patrick

 

My first suggestion is to get the codes read. We could play 1000 guesses, but with code information we would be able to rule some things out. Your first to "guesses" sound about right, although if the MAF is blown, there is no cleaning that will revive it. It could also be a steering sensor, but not likely given when it happens. You are doing a soft reset on the CEL, by turning the car off. You could try disconnecting the battery for like 109 minutes and see if anything comes back. This is a harder reset. GL