Meez

My dilemma:

I am getting consistent TC failure codes every time I drive the car hard. The car will go into limp mode and not allow me to drive past 10mph.
Initially occurred at the 30° embankment at Auto Club Speedway where I had to tow it home as resetting the battery wouldn't clear the codes / get it to go off limp mode.

The dealer replaced the accelerator pedal, throttle sensor, and the entire ECU module as they believed it to be an electrical issue. Apparently that was not the problem, as I was out at Buttonwillow Raceway and the error occurred again and it was my first warm up lap of the day! (wasn't driving fast). This time, I was able to reset the code and get it off limp mode so I could drive to the dealer.

The codes did not save and I was given the car back to recreate the code so they may do their diagnostics. This is when I thought I would have to do some crazy driving on the streets to get the error to throw. But It happened simply leaving the driveway of a gas station under acceleration. TC failure, limp mode. Towed it to the dealer where she sits at this very moment.

The dealer wants me to throw a completely stock exhaust on the vehicle before they troubleshoot any longer.). I currently have a complete Fabtech system on the car (I bought the car with this system equipped from a Porsche dealer and did not receive the stock system). I have found them to be ridiculously expensive and hard to source.

So I need to borrow your stock GT3 system (headers to tips)! Hopefully I can find someone willing to do this? Or simply shine some light on my situation?



Thank you fellow RLers.

F1CrazyDriver

Check battery terminals torque correctly - test battery and test alternator.

Once, with my Turbo, after driving hard and parking the car. Came back 15 minutes later , enter key - no lights - no nothing. I thought the car died on me after driving hard - turned out the battery terminals were lose hence my issue.
997 is much more sensitive then a 996, I'd start w/ the above 3.

Meez

thank you for your reply. I'll look into that.

jaundice

Where are you located? I have stock 997.2 GT3 headers and center muffler. You would just need to find side mufflers.

DD GT3 RD

Help this man out. He's a stand up guy.

Meez

I am in Los Angeles!

I am truly thankful for the offer, seriously. It makes me feel all warm and fuzzy inside knowing there are complete strangers willing to help me out.

I have struck luck and have found someone up the coast from me with the headers. It won't be hard for me to find the rest.

If this doesn't work out I may contact you. Thank you again!

Meez

Spyerx

TC Failure and going to limp mode is weird. What dealer are you working with (PM if you want). That's an odd request to remove exhaust.

I had a TC failure notice on my car (a .1) that was due to a PASM shock failing.

The TC system isn't super complicated. There are a few inputs:
speed
lateral/long acceleration
individual wheel speeds
etc

And it controls
e gas
individual wheel braking


Post what codes they find and the diagnosis. I'm going to place my bet on a wheel speed sensor or one of the accelerometers.

Mike J

Changing the exhaust back sounds like a total red herring, and I have seen this before at the Stealership as an excuse. If those are the inputs/outputs, what does the exhaust have to do with it?

How long have you had the car, and how many track events? I am asking if there is a history of clean running with that exhaust with no codes - if so the exhaust is likely not an issue.

Cheers,

Mike

CRex

Exactly what he said. I'm betting it's a wheel speed sensor. Not difficult to diagnose--plug in PIWIS (or PIWIS II) at the dealers, take car out for a spin while logging the four wheel speeds. Will insta see if you have aberrant readings from a particular wheel.

mooty

long shot.
do you hve oem steering wheel? has it every been takenoff?
there is a connector/notch in the column. i took my oem str wheel off to put momo on.
when first done, i have the same issues you mentioned. we took wheel off and made sure all is lined up then the issue went away

entityx

When did you last replace your battery? Had a buddy on here that kept having electrical gremlins related to TC and a new battery fixed them

awew911

Other than O2 sensors, the exhaust is passive, and how would exhaust play any roll in TC? I'm with Spyrex.. Accelerometer (located mid car under dash) or a wheel sensor.

Meez

I will ask for the codes tomorrow when I pick up the vehicle. They replaced the wheel sensors and I should find out if that worked this weekend. Thank you.



I bought the car in November 2015 (with the exhaust) and have taken it to at least 8 track events with absolutely no issues. It was only until after a track day at Auto Club Speedway while hitting the oval embankment that the car lit up like a Christmas tree. So the exhaust is a non-issue and they aren't necessarily trying to blame the exhaust for the problem. They just feel more comfortable getting that issue out of the way.

The exhaust has always thrown an emissions code. After a reset it takes about 10 miles for it to appear again. It was bought from a Porsche dealer.

Thank you for the information, it is truly appreciated.

I have not modified the OEM steering wheel but I do not know if a previous owner has. It is possible and if the wheel sensor replacements don't work I will keep this in mind. Thank you.

I have not replaced the battery under my ownership. I informed them to check the terminals. Thank you.

fayraree

@Meez not sure if you’re still around but curious if you could share what the problem was. I had a similar issue very recently, going full throttle on a sweeping ramp with a slight embankment and the TC fail light came on with limp mode.

Read the codes and it was “potentiometer” or wheel speed sensor. I had the car battery disconnected for several weeks recently so maybe I need to drive. Had the codes reset last weekend and the light and limp mode came back today with a couple of drives in between. Having a dealer read them while car is in for service (a friend did it last time).