2002 LS1 From C5. Random throttle lockout
2002 LS1 From C5. Random throttle lockout My swap uses an LS1 from a 2002 Corvette and I'm using the Drive By Wire setup. Everything is working good except on occasion, while driving, the computer will lock the Throttle Position at 14.9% and the accelerator pedal completely stops working. When this happens HP Tuners shows the code "P1514 - Airflow to TP Sensor Correlation High (SES, Pending, Current, History)."
If I turn the car off and wait a few seconds then everything goes back to normal. Also, if I "Clear DTC's" without turning the car off it immediately goes back to normal.
I was able to duplicate the behavior of the Pedal staying at 0% and Throttle Position goes to 14.9% by disconnecting the wire harness from the TPS sensor. This, along with the code, leads me to believe that it's TPS related. But i also don't know about the different limp modes that the PCM might go into.
This behavior did start occurring after getting the car tuned.
So I'm curious if anyone had insight on what might be causing this, or if I should attempt to replace the TPS sensor, or...
Thanks!
If I turn the car off and wait a few seconds then everything goes back to normal. Also, if I "Clear DTC's" without turning the car off it immediately goes back to normal.
I was able to duplicate the behavior of the Pedal staying at 0% and Throttle Position goes to 14.9% by disconnecting the wire harness from the TPS sensor. This, along with the code, leads me to believe that it's TPS related. But i also don't know about the different limp modes that the PCM might go into.
This behavior did start occurring after getting the car tuned.
So I'm curious if anyone had insight on what might be causing this, or if I should attempt to replace the TPS sensor, or...
Thanks!
TECH Fanatic
Joined: Jan 2018
Posts: 1,059
Likes: 198
It would be interesting to data log these parameters and see if any of them get strange before the problem strikes:
- RPM
- load (g/cyl)
- TPS
- accelerator pedal angle
There are tables that defines the expected and highest-allowed airflow value for a particular RPM, or RPM + throttle blade angle. If airflow exceeds that value, the PCM assumes that something in the DBW system is defective. You could try increasing the values in that table by 10% or so to see if that helps. That table is there to prevent disaster if something goes bad, so I wouldn't want to go crazy with it. But you probably want to at least multiply them by however much your peak torque has increased over stock (e.g. 50% more torque -> multiply all cells by 1.5).
Replacing the TPS sounds cheap and easy so I'd try that if its output looks suspicious in the data log, or if you end up having to make inexplicably huge increases to the expected-airflow tables.
- RPM
- load (g/cyl)
- TPS
- accelerator pedal angle
There are tables that defines the expected and highest-allowed airflow value for a particular RPM, or RPM + throttle blade angle. If airflow exceeds that value, the PCM assumes that something in the DBW system is defective. You could try increasing the values in that table by 10% or so to see if that helps. That table is there to prevent disaster if something goes bad, so I wouldn't want to go crazy with it. But you probably want to at least multiply them by however much your peak torque has increased over stock (e.g. 50% more torque -> multiply all cells by 1.5).
Replacing the TPS sounds cheap and easy so I'd try that if its output looks suspicious in the data log, or if you end up having to make inexplicably huge increases to the expected-airflow tables.
