Vf430

I just bought a 2003 Z06 with Nick Williams 102 mm throttle Body H/C work done to it.

I get these only every 300 miles or so, car goes into limp mode. Restart clear up codes everything is fine/.

Any idea what could cause this?

P1515 is a TPS code
C1278 is traction disable code

Based on my research here , it looks like P1515 triggers limp mode and C1278.

Appreciate if someone can guide a new vette owner.

Thanks

Vf430

Anyone?

BigGun

That code is often found to be a bad connection or short in the wire to the tps. It can be a pita to locate the problem. I am not familiar with the Nick Williams throttle body but I would look closely at the connector and pins. There is a lot of information on the forum if you search the code.

Jeff in Den

DTC 1515 sets if the PCM detects an out of range condition between the commanded and the actual throttle position.
Possible mechanical or binding that may be temperature related, water intrusion, or connectivity/wiring.
When 1515 is set, the MIL light should light, the TAC system is commanded to operate in the Reduced Engine Power mode or under certain conditions commands the engine to OFF, and the message center displays Reduced Engine Power.
Condidtions for clearing:
3 consecutive ignition cycles that the diag runs and does not fail, a current DTC (last test failed) clears when the diag runs and passes. A history DTC clears after 40 counsecutive warm up cycles if no failures are reported.
DTC 1278 TCS Temporarily inhibited by PCM, is set when the PCM diagnoses a condition preventing the engine control portion of traction control.
Your 1515 DTC problem is more then likely setting DTC1278 as it cannot properly control the trottle and thus effect traction control. Your throttle body work is highly suspect.

Vf430

Thanks for the feedback. I will double check the Tps connections today. The strange thing is if its bad connection would it not occur more frequently? It happened once at the track and once on the street both times followed by loss of traction or traction control active situation. Usually accelerating from low speed.

After resetting the car i have driven the car hard , low speed , forcing traction control light on etc. Several different situations over 500 miles it doesnt come back.

BigGun

Are you really stomping the pedal when this happens? Maybe take a look in the floorboard while your checking things.

LiteraCola

Check the connection at your Throttle Control, the little motor that actually operates your throttle body. Its on the driver side and has two wires running to it with a little connector. Wiggle those wires and the connector while the car is running and see if that makes a different. I struggle with similar issues for 2 years intermittently and after a numerous headaches I found that connector to be faulty. I believe Gene Culley stocks the connectors...
Good luck buddy.

skull

i have been trying to figure this out for months i have a ported fast 90mm with a ls2 tb. i get this code all the time but it almost always throws the code when i leave from a light! its done it ever since the install of my intake setup, my friend said the computer had to relearn and it would go away. well that was 4 months and 3k miles ago

Vf430

Not sure which little motor you are referring to , i checked the following today. All looks good.

1. The functioning of the throttle body plates , the motor is working opening and closing. But i hear a whine from the throttle body motor not sure its normal. All tests perfomed by turning the ignition on and pressing the accelerator pedal.

2. Checked for obstructions inside vararam intake all looks good.

3 the yellow wire harness to the throttle body looks good

4 under the battery for acid leak everything looks clean.


I am having this issue on the track only , usually when i open throttle coming out of turns. Not sure if it makes any difference.

Vf430

Yes it happens only on track. At very high temp days. Like now in chicago 95 f. Not sure what else would trigger p1515 code. My last thing to check is the actual harness and plug to TAC module.

Any other ideas ? I love this car so much at track. Just want to run consistently.

BigGun

So did you check the connections down at the accelerator? That might throw a different code but worth taking a look.

LiteraCola

The little motor that actually operates the throttle body. It's a two-wire harness that plugs into the driver side of the throttle body. I believe the wires are yellow and brown? or yellow and green...

Jeff in Den

The wires on the throttle actuator control motor (left side) to pcm Throttle actuator control module are:
A-Yellow
B-Brown

The wires on the Throttle Position Sensor (right side) to pcm throttle control module) are:
A-Dark Green
B-Purple
C-Dark Blue
D-Yellow/Black
E-White
F-Pink

The wires on the Accelerator pedal position sensor (top of pedal) to the Throttle actuator control module (attached to pcm below battery):
A-Grey
B-Purple
C-Light Blue
D-Tan
E-Yellow/Black
F-Dark Blue
G-Light Blue
J-Brown
K-Dark Green

Vf430

Thanks . I checked the working of wires to the actual TB motor and TPS. Now i have to check the accel pedal and TAC module connections. Hopefully its something there.

In order to get to the TAC module do i have to remove the wheel and wheel well cover?

LiteraCola

Yes you do.

I'm sorry you're having so much trouble with your car. God knows I've been there. I fought my car for far too long and eventually stopped enjoying it... :-/ hope it all works out.