P1654

Diagnostic Chart (cont'd):

Wiring Diagram:

Circuit Description
A dash light is illuminated by the PCM if the diagnostic has detected certain errors related to the Accelerator Pedal Position (APP) sensor. When the PCM is commanding the Service Throttle Soon Lamp ON, the voltage potential of the circuit will be low (near 0 volts). When the PCM is commanding the Service Throttle Soon Lamp OFF, the voltage potential of the circuit will be high (near the battery volts). The primary function of the PCM in this circuit is to supply the ground for the Service Throttle Soon Lamp. This is a type D DTC.

Conditions for Setting the DTC

^ The Service Throttle Soon lamp is requested ON.
^ The voltage on the Service Throttle Soon control circuit is high (near the battery volts).

OR

^ The Service Throttle Soon lamp is requested OFF.
^ The voltage on the Service Throttle Soon control circuit is low (near 0 volts).

Action Taken When the DTC Sets
Will not turn the Malfunction Indicator Lamp (MIL) ON.

Conditions for Clearing the MIL/DTC

^ The PCM will turn the MIL off after three consecutive trips without a fault condition.
^ A History DTC will clear after forty consecutive warm-up cycles during which the diagnostic does not fail (the coolant temperature has risen 5°C (40°F) from the start up coolant temperature and the engine coolant temperature exceeds 71°C (160°F) during that same ignition cycle).
^ Use of a Scan Tool will clear the DTC codes.

Diagnostic Aids
A malfunctioning bulb or the control circuit is shorted to ground will cause a P1654 to set.

Test Description
The number(s) below refer to the Step number(s) on the Diagnostic Table.

2. Be sure that both the ON and the OFF states are commanded. Repeat the commands as many times as necessary.
9. If no trouble is found in the control circuit or the connections at the PCM, the PCM maybe malfunctioning, however, this is an extremely unlikely failure.