Diagnostic Aids

Scan tool reads APP 3 sensor position in volts. With throttle closed and ignition on or at idle, voltage should be 4 volts. Voltage should decrease at a steady rate as throttle is moved toward Wide Open Throttle (WOT). Ninety percent pedal travel is acceptable for correct APP sensor operation. Scan APP 3 sensor while depressing accelerator pedal with ignition on, engine off. Display should vary from about 4 volts with throttle closed to about 2 volts with throttle held at WOT.

Check for intermittent problems (i.e., poor connections, rubbed through wire insulation or broken wire inside its insulation). See appropriate TROUBLE SHOOTING - NO CODES article.