TP sensor 1 voltages and limp mode?
Thread Starter
Teching In
Joined: Jun 2021
Posts: 35
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TP sensor 1 voltages and limp mode? Hi all, I have a 2002 c5 with a swapped crate ls3, that I appear to have wrong voltage readings at the TP Sensor 1.
Some car specs: LS3 crate motor, GM LS2 throttle body, 2002 OEM PCM, needs to be dyno tuned but runs ok for now, LS3 MAP sensor, LS6 MAF sensor. I have used Racetronix sensor adapters for the MAP/MAF sensors. All emissions removed and only 2 forward O2 sensors.
I just read the TP sens 1 voltage readings should be TP sensor 1 signal voltage increases at the
same time that the throttle opens. The voltage increases, from approximately 1 volt at 0 throttle tols3base1.4.hpt
above 3.5 volts at 100 percent throttle. But I am seeing 1.25 volts at 0% throttle and 4.47 volts at 100% throttle using my Tech2.
I have tried swapping another (same part#) GM LS2 throttle body with exact same readings, which leads me to believe the TB is not the problem.
I am asking the forum community because the car went into Limp mode twice after about 5 laps around the track. The car did not throw any codes at that time. but It did throw these codes previously: P1120-TP sensor 1 circuit, P1220 TP sensor 2 circuit, P1221 Fuel pump secondary circuit, and P1516 TAC module throttle actuator position performance.
I have 3 questions basically. 1) would a proper dyno tune cure this? I don't think so but I'm no expert by any imagination and 2) what has caused the hi Voltage readings for TP sens 1 and what can I do to fix this? And would the hi voltages throw car in Limp Mode? Ok 4 questions.....
I attached base tune below. Thanks ALL! Brian..
Some car specs: LS3 crate motor, GM LS2 throttle body, 2002 OEM PCM, needs to be dyno tuned but runs ok for now, LS3 MAP sensor, LS6 MAF sensor. I have used Racetronix sensor adapters for the MAP/MAF sensors. All emissions removed and only 2 forward O2 sensors.
I just read the TP sens 1 voltage readings should be TP sensor 1 signal voltage increases at the
same time that the throttle opens. The voltage increases, from approximately 1 volt at 0 throttle tols3base1.4.hpt
above 3.5 volts at 100 percent throttle. But I am seeing 1.25 volts at 0% throttle and 4.47 volts at 100% throttle using my Tech2.
I have tried swapping another (same part#) GM LS2 throttle body with exact same readings, which leads me to believe the TB is not the problem.
I am asking the forum community because the car went into Limp mode twice after about 5 laps around the track. The car did not throw any codes at that time. but It did throw these codes previously: P1120-TP sensor 1 circuit, P1220 TP sensor 2 circuit, P1221 Fuel pump secondary circuit, and P1516 TAC module throttle actuator position performance.
I have 3 questions basically. 1) would a proper dyno tune cure this? I don't think so but I'm no expert by any imagination and 2) what has caused the hi Voltage readings for TP sens 1 and what can I do to fix this? And would the hi voltages throw car in Limp Mode? Ok 4 questions.....
I attached base tune below. Thanks ALL! Brian..
