TPS - What is normal?

[sharem]

Using an Actron AutoScanner to view PID data on a 1997 Explorer w/V-8 engine, I notice the absolute throttle position (ABSLT TPS) reads 21.6% at idle. Is this normal, or should it be closer to zero? Also, is there somewhere I can find normal operating ranges for various PIDs (like short term fuel trim or oxygen sensor)?

 

[2000StreetRod]

closed throttle absolute TPS

21.6% absolute TPS at closed throttle is normal. As I recall mine is about 18%. I believe the PCM reads the TPS output at ignition turn on as the closed throttle value. There's a "latch" routine that periodically checks for a lower value and uses it if found.

I don't know of a source for the normal range of various PIDs. The OBD System Operation Summary provides some fault values for various sensor outputs: OBDII Theory & Operation

O2S degrade with age, new: 0.95 to 0.07 volts, aged: 0.83 to 0.09 volts

The PCM adjusts the LTFT to keep the STFT within a certain range. When the LTFT exceeds a preset value a DTC is supposed to get set.