P0629

P0629-FUEL PUMP CONTROL CIRCUIT HIGH

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

- When Monitored:
With the engine running and the battery voltage greater than 10.4 Volts.

- Set Condition:
The Powertrain Control Module (PCM) detects that the fuel pump control circuit is high.





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

Diagnostic Test

1. DIAGNOSTIC TROUBLE CODE (DTC) IS ACTIVE
1. Attempt to start the engine. If the engine will not start, crank the engine for five seconds.

WARNING:
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.

2. Using the scan tool, read the active DTCs.

Does the scan tool display P0629-FUEL PUMP CONTROL CIRCUIT HIGH?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

2. FUEL PUMP RELAY
1. Turn the ignition off.
2. Install a known good Fuel Pump Relay.
3. Attempt to start the engine.

Does P0628 return?

Yes

- Go To 3

No

- Replace the fuel pump relay.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

3. FUEL PUMP CONTROL CIRCUIT SHORTED TO GROUND
1. Turn the ignition off.
2. Remove the Fuel Pump Relay.
3. Disconnect the Powertrain Control Module (PCM) C1 harness connector.
4. Turn the igition on.
5. Measure the voltage on the Fuel Pump Control circuit in the PCM C1 harness connector.

Is there voltage present?

Yes

- Repair the short to voltage in the Fuel Pump Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Go To 4

4. FUEL PUMP CONTROL CIRCUIT OPEN
1. Turn the ignition off.
2. Measure the resistance of the Fuel Pump Control circuit between the relay terminal and the Powertrain Control Module (PCM) C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Go To 5

No

- Repair the high resistance in the Fuel Pump Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

5. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Relay 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.
4. Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

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

No

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