P0627
P0627 - Fuel Pump Control Circuit
For wiring diagrams, refer to.
• 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. Refer to => Non-DTC Based Diagnostics. Pre-Diagnostic Troubleshooting Procedure
Test Step 1 - DTC is Active
• Attempt to start the engine. If the engine will not start, crank the engine for 5 seconds.
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 Test Step 2 => [ Test
Step 2 - Fuel Pump Control Circuit Shorted to Voltage ]
No
• Refer to the checking for an intermittent DTC diagnostic procedure. Refer to => Non-DTC Based Diagnostics. Checking for an Intermittent DTC
Test Step 2 - Fuel Pump Control Circuit Shorted to Voltage
• Turn the ignition OFF.
• Disconnect the totally integrated power module C1 connector.
• Disconnect the PCM C3 connector.
• Turn the ignition ON.
• Measure the voltage of the fuel pump control circuit in the totally integrated power module harness connector.
Is there any voltage present?
Yes
• Repair the short to voltage in the fuel pump control circuit.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Go to Test Step 3 => [ Test
Step 3 - Fuel Pump Control Circuit Shorted to Ground ]
Test Step 3 - Fuel Pump Control Circuit Shorted to Ground
• Turn the ignition OFF.
• Measure the resistance between ground and the fuel pump control circuit in the totally integrated power module harness connector.
Is the resistance less than 100 ohms?
Yes
• Repair the short to ground in the fuel pump control circuit.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Go to Test Step 4 => [ Test
Step 4 - Fuel Pump Control Circuit Open or High Resistance ]
Test Step 4 - Fuel Pump Control Circuit Open or High Resistance
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 fuel pump control circuit between the totally integrated power module harness connector and the appropriate terminal of special tool #8815.
Is the resistance less than 5.0 ohms?
Yes
• Go to Test Step 5 => [ Test
Step 5 - Totally Integrated Power Module Actuation ]
No
• Repair the open or high resistance in the fuel pump control circuit for an open circuit or high resistance.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
Test Step 5 - Totally Integrated Power Module Actuation
• Connect the PCM C3 connector.
• Turn the ignition ON.
• With the scan tool, actuate the fuel pump control.
• Using a test lamp connected to 12 volts, check the fuel pump control circuit in the totally integrated power module harness connector.
• The test lamp 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 lamp illuminated and bright proportional to the duty cycle allowed by the PCM during actuation?
Yes
• Go to Test Step 6 => [ Test
Step 6 - Totally Integrated Power Module ]
No
• Go to Test Step 7 => [ Test
Step 7 - PCM ]
Test Step 6 - Totally Integrated Power Module
• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the totally integrated power module and the powertrain control module.
• 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. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Replace and program the PCM.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
Test Step 7 - PCM
• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the totally integrated power module and the powertrain control module.
• 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. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Replace and program the PCM.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test