P0627

P0627-FUEL PUMP CONTROL CIRCUIT/OPEN

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





- When Monitored:
With the ignition on. Battery voltage greater than 10.4 Volts and the ASD sense switch is on.

- Set Condition:
MIL code set when the Fuel Pump relay does not activate and the Powertrain Control Module (PCM) detects a signal outside the calibrated threshold on the Fuel Pump Control circuit.





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

Diagnostic Test

1. ACTIVE DTC
1. Ignition on, engine not running.
2. With the scan tool, select View DTCs.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition Test.

2. CHECK THE (K31) FUEL PUMP CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Remove the Fuel Pump Relay.
4. Ignition on, engine not running.
5. Measure the voltage on the (K31) Fuel Pump Control circuit at the Fuel Pump Relay socket in the PDC.

Does the voltmeter indicate voltage present?

Yes

- Repair the (K31) Fuel Pump Control circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 3

3. CHECK THE (K31) FUEL PUMP CONTROL CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Measure the resistance of the (K31) Fuel Pump Control circuit from the PCM C1 harness connector to the appropriate terminal of the Fuel Pump Relay socket in the PDC.

Is the resistance below 5.0 Ohms?

Yes

- Go To 4

No

- Repair the (K31) Fuel Pump Control circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

4. CHECK THE (K31) FUEL PUMP CONTROL CIRCUIT FOR A SHORT TO GROUND
1. Measure the resistance between ground and the (K31) Fuel Pump Control circuit in the Fuel Pump Relay socket.

Is the resistance above 10k ohms?

Yes

- Go To 5

No

- Repair the (K31) Fuel Pump Control circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

5. CHECK THE FUEL PUMP CONTROL OPERATION FROM THE PCM
1. Turn the ignition off.
2. Connect the PCM C1 harness connector.
3. Ignition on, engine not running.
4. With a 12-volt test light connected to B+, probe the (K31) Fuel Pump Control circuit in the Fuel Pump Relay socket.
5. Using the scan tool in the PCM, actuate the Fuel Pump.

NOTE: The test light should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery.

Does the test light illuminate accordingly during the actuation?

Yes

NOTE: Before continuing, check the PDC harness connector terminals for corrosion, damage or terminal push out. Repair as necessary.
If OK, replace the Fuel Pump Relay.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 6

6. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Power Distribution Center (PDC) and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Fuel Pump Relay and Control Module connectors.
4. Refer to any Technical Service Bulletins that may apply.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Replace and program the Powertrain Control Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test