P0627

P0627-FUEL PUMP CONTROL CIRCUIT





For a complete wiring diagram refer to Diagrams/Electrical.


- When Monitored:

With the ignition on. Battery voltage greater than 10.4 volts and the ASD sense switch is on.

- Set Condition:

Actual Fuel Pump state is not equal to desired state. One Trip Fault. Three good trips to turn off the MIL.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.


Diagnostic Test


1. ACTIVE DTC

Ignition on, engine not running.

With the scan tool, select View DTCs.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition


2. FUEL PUMP CONTROL OPERATION FROM THE PCM





Stop the Fuel Pump actuation.

Turn the ignition off.

Disconnect the C1 TIPM harness connector.


NOTE: Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Ignition on, engine not running.

Using a 12-volt test light connected to B+ probe the (K31 Fuel Pump Control circuit in the C1 TIPM harness connector.

Using a scan tool actuate the Fuel Pump under the PCM actuations.

Does the test light illuminate brightly during the actuation?

Yes

- Go To 5

No

- Go To 3


3. (K31) FUEL PUMP CONTROL CIRCUIT OPEN





Turn the ignition off.

Disconnect the C3 PCM harness connector.


CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

Measure the resistance of the (K31) Fuel Pump Control circuit from the C1 TIPM harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes

- Go To 4

No

- Repair the open in the (K31) Fuel Pump Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test


4. (K31) FUEL PUMP CONTROL CIRCUIT SHORTED TO GROUND





Measure the resistance between ground and the (K31) Fuel Pump Control circuit in the TIPM C1 harness connector.

Is the resistance below 100 ohms?

Yes

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

No

- Go To 8


5. (N1) FUEL PUMP OUTPUT CIRCUIT OPEN





Turn the ignition off.

Disconnect the C5 TIPM harness connector.

Disconnect the Fuel Pump Module harness connector.

Measure the resistance of the (N1) Fused Fuel Pump Output circuit from the C5 TIPM harness connector and the Fuel Pump Module harness connector.

Is the resistance above 5.0 ohms?

Yes

- Repair the open in the (N1) Fused Fuel Pump Output circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 6


6. (N1) FUEL PUMP OUTPUT CIRCUIT SHORTED TO GROUND





Measure the resistance between ground and the (N1) Fused Fuel Pump Output circuit at the Fuel Pump Module harness connector.

Is the resistance below 100 ohms?

Yes

- Repair the short to ground in the (N1) Fused Fuel Pump Output circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 7


7. FUEL PUMP MODULE/TIPM





Connect the C3 PCM harness connector.

Connect the C1 and C5 TIPM harness connectors.

Turn the ignition on.

Using a scan tool actuate the Fuel Pump Module.

Using a 12-volt test light connected to ground, probe the (N1) Fused Fuel Pump Output circuit at the Fuel Pump Module harness connector.

Does the test light illuminate?

Yes

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

No

- Replace the Totally Integrated Power Module.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test


8. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

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