P0627

P0627-FUEL PUMP CONTROL CIRCUIT





For complete wiring diagrams 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. FUEL PUMP OPERATION

Ignition on, engine not running.

With a scan tool in the PCM, actuate the Fuel Pump.

Is the Fuel Pump operating?

Yes

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 2

2. (K31) FUEL PUMP CONTROL CIRCUIT SHORTED TO VOLTAGE





Stop the Fuel Pump actuation.

Turn the ignition off.

Disconnect the C3 PCM harness connector.

Ignition on, engine not running.

Measure the voltage on the (K31) Fuel Pump Control circuit at the C1 TIPM harness connector.

Does the voltmeter indicate voltage present?

Yes

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

No

- Go To 3

3. (K31) FUEL PUMP CONTROL CIRCUIT OPEN





Turn the ignition off.


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 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 POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 5

5. FUEL PUMP CONTROL OPERATION FROM THE PCM





Turn the ignition off.

Connect the C3 PCM harness connector.

Ignition on, engine not running.

Using the scan tool in the PCM, actuate the Fuel Pump.

With a 12-volt test light connected to ground, probe the (K31) Fuel Pump Control circuit in the TIPM C1 harness connector.

Does the test light illuminate brightly and flash on an off?

Yes

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

No

- Go To 6

6. 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 POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

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