P0627-FUEL PUMP CONTROL CIRCUIT





For a complete wiring diagram Refer to Section 8W.


  • 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.


Possible Causes
  
(K31) FUEL PUMP CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE
  
(K31) FUEL PUMP CONTROL CIRCUIT SHORTED TO GROUND
  
(K31) FUEL PUMP CONTROL CIRCUIT OPEN
  
TIPM
  
PCM
  

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).



Diagnostic Test

1.FUEL PUMP OPERATION




Is the Fuel Pump operating?

Yes


No
  • Go To 2

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










Does the voltmeter indicate voltage present?

Yes


No
  • Go To 3

3.(K31) FUEL PUMP CONTROL CIRCUIT OPEN




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.




Is the resistance below 5.0 ohms?

Yes
  • Go To 4


No

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





Is the resistance below 100 ohms?

Yes


No
  • Go To 5

5.FUEL PUMP CONTROL OPERATION FROM THE PCM









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 in accordance with the Service Information.


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.




Were there any problems found?

Yes


No