Help! Throttle position sensor error

PeteB

GT40s Supporter
Hmmm...same throttle body as my Pontiac G8. Think I'll cannibalize my G8 next weekend and put the G8 TB on the SL-C and drive around a bit. If if fixes the problem, I'll know it's the TB before I go and spend another $135 on a part I don't need.
 

PeteB

GT40s Supporter
Well, swapped in the throttle body from the G8. I got a whole 100 yards before the check engine light came on and no throttle.

Thing that is really weird is if I cycle the battery cutoff, then the check engine light stays on, but the throttle works.

Getting code 2127 now.
 
you need to make sure you're using the same TB that the ECU is programmed for - either silver (older LS) or gold (newer LS).

did you start having problems after a dyno tune? If so it's possible your tuner could have played with the DBW tables inadvertently ... those are usually flagged with big warning messages like 'may brick ecu' ... the problem is playing with them might work, or it might work for a few hundred miles then mess up the ecu permanently, or it could brick the ecu immediately .... nobody really knows what will or won't damage the ecu if you play w/ those tables
 

PeteB

GT40s Supporter
I started having problems over 1000 miles after the tune. The TB has been working for 1500+ miles so I'm sure I've got the right one.
 
do you have the original tune? if so you might want to compare the dbw tables (e.g., pedal position vs throttle opening) to see if they were changed.

if they were, the ecu may be damaged

i was initially going to play with mine because there is a dead spot in the thorttle for the first 10%. but every forum post said NO! to it so i didn't and just ended up pre-loading the gas pedal with a bolt (pre-loading a gas pedal .. safety first, right, lol)

failing that it might be a short in the wiring harness itself - with one of the GMPP wiring harness I got the gas pedal would randomly work for several prsses, then stop until i unhooked the battery. it was something within the harness because when i swapped harnesses (same ecu/tb/pedal) the problem immediately went away.
 

PeteB

GT40s Supporter
Well, I've now eliminated the throttle body as the problem. New TB and happened again. Next step is take it to a tuner I guess...:cry:

Anyone need a TB or gas pedal? I've now got a spare of each.
 
Ug.... sorry to hear it but keep us posted. Likely you won't be the only one who has this problem going forward.

edit: and to add to your earlier question about Chevrolet Performance technical support. I hope someone can find a way to contact them via phone.

I spent a good part of yesterday trying to track down someone there who could help with my questions on the LS3 crate engine controller with no success whatsoever, including a trip to the dealership (both parts department and service department).
 

PeteB

GT40s Supporter
pulled back the carpet and traced the throttle wires back to the computer to make sure the wires weren't damaged anywhere. I did find a place where the wires were pinched under one of the passenger seat brackets. The wires don't appear to be damaged but it's the only thing I can figure out.

Sooo...can I cut the section out and splice? Do I need to rewire all the way back to the the computer?
 

Ken Roberts

Supporter
No problem Pete as long as you practice good wire splicing techniques.

The only wiring you can not splice is on the oxygen sensor.....between the sensor and the wiring connector. You can buy harness extensions that go in between the male and female connectors as that is acceptable but the replacement sensor that you purchase has to be installed as is.
 
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