P1206

P1206-FUEL PUMP CONTROL MODULE OPEN CIRCUIT TO FUEL PUMP

For a complete wiring diagram, refer to the Wiring Information.





Theory of Operation

When the Powertrain Control Module (PCM) receives a 'Start' or 'Run' signal from the ignition; It energizes the Fuel Pump relay which sends a continuous 12 volt supply to the Fuel Pump Control Module (FPCM). The PCM also sends a control signal directly to the FPCM which regulates the Pulse Width Modulated (PWM) voltage that will be sent to the Fuel Pump Module. The PWM will vary from 10-100% depending on the input of the Fuel Rail Pressure sensor and other engine demands. The Powertrain Control Module (PCM) receives a Pulse Width Modulated (PWM) signal from the Fuel Pump Control Module (FPCM) representing the state of all inputs and outputs of the FPCM. This is a Constant Pressure Fuel system which means any Delta Pressure test performed on the Fuel Pump would show a continuous pressure (regardless of the changes in PWM). If a pressure sensor fails or other failures are present; The duty cycle goes to Limp mode (100%) to maintain fuel pressure.

- When Monitored:
Engine running. Battery voltage greater than 11.0 volts.

- Set Conditions:
An open circuit or high resistance is detected on the Fuel Pump Control Module (FPCM) Pump Feed circuit. Sets the MIL after failure matures for 60 seconds.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

Diagnostic Test

1. ACTIVE DTC
1. Turn the ignition on, engine not running.
2. With the scan tool, read DTCs.

Is the DTC active?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

2. CHECK THE (N13) FPCM PUMP FEED CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the FPCM harness connector.
3. Lower the Fuel Tank to gain access to the Fuel Pump Module harness connector.
4. Disconnect the Fuel Pump Module harness connector.
5. Measure the resistance of the (N13) FPCM Pump Feed circuit between the FPCM harness connector and the Fuel Pump assembly harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go To 3

No

- Repair the (N13) FPCM Pump Feed circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

3. CHECK THE (N14) FPCM PUMP RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (N14) FPCM Pump Feed circuit between the FPCM harness connector and the Fuel Pump assembly harness connector.

Is the resistance below 5.0 ohms?

Yes

- Replace the Fuel Pump assembly.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Repair the (N14) FPCM Control circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.