Fail Safe Mode Throttle Body Gremlin

[Stig_v5.0]

Hello everyone,

I’m trying to get some insight into a problem I’m having recently. Here’s the history

2014 GT Manual
Purchased used with 8,500 miles
Installed VMP TVS Stage 2 kit myself at 47,000 miles.

The car ran and drove and pulled perfectly for about 7,500 miles.

Then one day I get a random fail safe mode for throttle voltage circuit correlation while I was idling. From what I understand, this means the car is seeing a different throttle angle than what it’s asking of the TB. This will clear itself after a shut down and restart.

Drove the car home and contacted VMP who asked for a log of the situation, unfortunately I can not recreate it. They tell me to check wiring. The car goes a few weeks without any issues then it randomly does it again this time at 60mph with the cruise control on. Again, shutdown and restart clears it.

This has repeated itself a handful of times at random intervals and random driving situations. Weeks at a time will pass where there are no issues and then BING fail-safe mode.

Last week I decided to replace the throttle body (stock GT500 twin 60mm) honestly just throwing parts at the thing at this point. Today it did it to me again.

I cannot for the life of me get this car to recreate the issue. I have manhandled the wiring harness Y-extension and stressed the connectors to hell by hand with the car running and not one hiccup can be forced upon the car.

In all my years of trying to diagnose an issue with any of my previous cars, I’ve never been as stumped as I am on this one. Any experience or insight with similar issues would be greatly appreciated.

Thanks

 

[Stig_v5.0]

Bump...?

 

[Riddick]

Probably something in the tune since you already swapped throttle bodies. I'd try logging the car under the conditions it happens in, maybe they will see something

Sent from my XT1097 using Tapatalk

 

[Zemedici]

The throttle body you replaced it with was a new unit?

 

[Ortiz99]

I tuned this CJ set up that was having the EXACT issues you are experiencing. Owner installed the CJ set up, loaded base tune to drive it over, no problems at all. It was driving just fine and there wasn't any issues until road testing started to take place. Man was it a pain to try and find the issue. I went over the wiring with nothing visible that seemed bad, checked the harness that split for the tb, seemed fine.

I raised the error thresholds high in the tune and still did it. I then just let it idle, I shook the damn harness that goes to the tb and bam, limp mode. Checked the inside of the connector and removed the little red piece on the inside since it had cracked and wedged itself in a way that wasn't making a solid connection.

After that, no issues and the owner was able to take it to TX2k racing it all night. Might not be your issue but it sure helped me find what was causing it. Granted, I have access to both tune and the vehicle on hand so it was easier for me to know that the tune wasn't the problem.