DH - Testing Notes

NOTE:
You should enter this Pinpoint Test only when you have been directed here from Diagnostic Routines.

REMEMBER:
To prevent the replacement of good components, be aware that the following non-Electronic Engine Controls (EEC) areas may be at fault:

- Idle speeds/throttle stop adjustment

- Binding throttle shaft/linkage or speed control linkage

- Choke/high cam system, if equipped

- Throttle Position (TP) sensor may not be seated properly (tightened down)

This Pinpoint Test is intended to diagnose only the following:

- TP sensor (9B989)

- Sensor harness circuits: VREF, TP, and SIG RTN

- Powertrain Control Module (PCM) (12A650)

Throttle Position Sensor Schematic:

DESCRIPTION
The TP Sensor is a potentiometer that sends a signal to the PCM that is directly proportional to throttle plate position.