• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

The fuel pump driver control module sends reports of the actual fuel pump speed to the engine control module (ECM) as serial data every 10 ms. The ECM calculates the error between the commanded fuel pump speed and the fuel pump speed that was reported from the fuel pump driver control module. A DTC will be set If the fuel pump speed is outside a calibrated threshold.

• DTC P1029, P102A, P102B, P102C, P1255, P12A6, or U18A2 is not set.
• Ignition voltage is greater than 11 V.
• KR73 Ignition Main Relay is commanded On.

The difference between the commanded fuel pump speed and actual fuel pump speed is outside a calibrated range for greater than 7 s.

DTC P129F is a Type B DTC.

DTC P129F is a Type B DTC.

Any failure that exists on the fuel pump output circuit (3 phases) will be manifested in a Fuel Pump Speed and may cause this DTC to set.

Engine Controls Schematics

Master Electrical Component List

Fuel System Description

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Control Module References for scan tool information

1. Ignition On.
2. Verify DTC P1029, P102A, P102B, P102C, P1255, P12A6, or U18A2 is not set.
• If any of the DTCs are set

  Refer to Diagnostic Trouble Code (DTC) List - Vehicle.

• If none of the DTCs are set
3. Verify the scan tool parameter:
• Fuel Pump Phase U-V-W Circuits Shorted Test Status=OK/Not Run
• If not the specified state

  Refer to: Circuit/System Testing

• If the specified state
4. Engine running.
5. Verify scan tool parameters Fuel Pump Speed Command and Fuel Pump Speed are within 250 RPM of each other while operating the vehicle through varying loads.
• If not within 250 RPM

  Refer to Circuit/System Testing

• If within 250 RPM
6. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
7. Verify DTC P129F did not set.
• If the DTC is set

  Refer to Circuit/System Testing

• If the DTC is not set
8. All OK.

1. Ignition/Vehicle & All vehicle systems » Off
2. Disconnect the electrical connector:@K111 Fuel Pump Driver Control Module&A7 Fuel Pump and Level Sensor Assembly
3. Test for less than 2 Ω between the test points:
• Control circuit terminal 8@Control module harness&Terminal 1@Component harness
• Control circuit terminal 9@Control module harness&Terminal 2@Component harness
• Control circuit terminal 24@Control module harness&Terminal 3@Component harness
• If 2 Ω or greater

  Repair the open/high resistance in the circuit.

• If less than 2 Ω
4. Test for infinite resistance between the test points:
• Control circuit terminal 8@Control module harness&Control circuit terminal 9@Control module harness
• Control circuit terminal 8@Control module harness&Control circuit terminal 24@Control module harness
• Control circuit terminal 9@Control module harness&Control circuit terminal 24@Control module harness
• If less than infinite resistance

  Repair the short between the circuits.

• If infinite resistance

Note: It may be necessary to remove engine components for the visual inspections.

5. Verify a condition does not exist with the component:A7 Fuel Pump and Level Sensor Assembly
• Restrictions
• Debris
• Contamination
• If a condition exists

  Repair or replace as necessary.

• If no condition exists
6. Replace the component:A7 Fuel Pump and Level Sensor Assembly
7. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
8. Verify the DTC does not set.
• If the DTC sets

  Replace the component:K111 Fuel Pump Driver Control Module

• If the DTC does not set
9. All OK.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• Fuel Tank Fuel Pump Module Replacement
• For control module replacement, programming and setup refer to Control Module References