Fuel Pump Monitor (FPM)

The fuel pump driver module (FPDM) communicates diagnostic information to the PCM through the FPM circuit. This information is sent by the FPDM as a duty cycle signal. The 3 duty cycle signals that may be sent are listed in the following table.

FUEL PUMP DRIVER MODULE (FPDM) DUTY CYCLE SIGNALS

Duty Cycle ⁽¹⁾

On Time (ms)

Comments

FP_M PID ⁽²⁾

50%

500

All OK output from FPDM. With this input, the PCM can verify that the FPDM is powered and able to communicate on the FPM circuit.

80-125%

25%

250

FPDM did not receive a fuel pump (FP) duty cycle command from the PCM, or the duty cycle that was received was invalid. Refer to POWERTRAIN CONTROL MODULE (PCM) OUTPUTS , Fuel Pump.

15-60%

75%

750

The FPDM has detected a fault in the circuits between the fuel pump and FPDM.

250-400%

⁽¹⁾	If a duty cycle meter and breakout box is used, be aware that these values may be reversed depending on the trigger setting of the specific meter (for example, 25% from FPDM may read as 75% on duty cycle meter depending on trigger setting).

⁽²⁾	Some diagnostic tools will display the FP_M PID as the duty cycle in column 1. Other diagnostic tools display the FP_M PID as a value shown in the FP_M PID column. This value fluctuates randomly. It is OK for the value to briefly go outside this range, then return.