P0627

P0627-FUEL PUMP CONTROL CIRCUIT





For a complete wiring diagram REFER to DIAGRAMS/ELECTRICAL


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

- Set Condition:
The PCM detects an open or shorted condition in the Fuel Pump control circuit.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.Initial Inspection and Diagnostic Overview


Diagnostic Test


1. DTC IS ACTIVE
Attempt to start the engine. If the engine will not start, crank the engine for 5 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 can result in personal injury or death.

With the scan tool, select View DTCs.
Is the status Active for this DTC?

Yes


- Go to 2


No


- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.Checking For An Intermittent DTC


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




Turn the ignition off.
Disconnect the C1 Totally Integrated Power Module (TIPM) connector.
Disconnect the C3 Powertrain Control Module (PCM) connector.
Turn the ignition on.
Measure the voltage of the (K31) Fuel Pump Control circuit in the Totally Integrated Power Module (TIPM) harness connector.
Is there any voltage present?

Yes


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


No


- Go to 3


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




Turn the ignition off.
Measure the resistance between ground and the (K31) Fuel Pump Control circuit in the Totally Integrated Power Module (TIPM) harness connector.
Is the resistance below 100 ohms?

Yes


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


No


- Go to 4


4. (K31) FUEL PUMP CONTROL CIRCUIT OPEN OR HIGH RESISTANCE




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 between the Totally Integrated Power Module (TIPM) harness connector and the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes


- Go to 5


No


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


5. TOTALLY INTEGRATED POWER MODULE (TIPM) ACTUATION




Connect the C3 Powertrain Control Module (PCM) connector.
Turn the ignition on.
With the scan tool, actuate the Fuel Pump control.
Using a 12 volt test light connected to 12 volts, check the (K31) Fuel Pump Control circuit in the Totally Integrated Power Module (TIPM) harness connector.

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.

Is the test light illuminated and bright proportional to the duty cycle allowed by the PCM during actuation?

Yes


- Go to 6


No


- Go to 7


6. TOTALLY INTEGRATED POWER MODULE (TIPM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Totally Integrated Power Module (TIPM) and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes


- Repair as necessary.
- Perform the PCM Verification Test.Powertrain Verification Test


No


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


7. POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Totally Integrated Power Module (TIPM) and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes


- Repair as necessary.
- Perform the PCM Verification Test.Powertrain Verification Test


No


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