Diagnostic Aids

Scan tester displays APP No. 2 position in volts and should display 4.5 volts with throttle closed and ignition on or engine at idle. Voltage should decrease at a steady rate as throttle is moved toward WOT.

Monitor APP No. 2 sensor while applying accelerator pedal with engine off and ignition on. Display should vary from about 4.5 volts with throttle closed, to about 1.5 volts with throttle at WOT. DTC 99 will set if a short to ground is present in 5-volt reference circuit.

Fig 1: DTC 99 Schematic ("G" Series) Accelerator Pedal Position (APP) NO. 2 (5-volt Reference Fault)

Fig 2: DTC 99 Schematic ("P" Series) Accelerator Pedal Position (APP) NO. 2 (5-volt Reference Fault)

Fig 3: DTC 99 Flow Chart (All Models) Accelerator Pedal Position (APP) NO. 2 (5-volt Reference Fault)