P12A6
DTC P12A6
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC P12A6
- Fuel Pump Driver Control Module Enable Circuit Performance
Diagnostic Fault Information
Circuit/System Description
The engine control module (ECM) provides ignition voltage to the fuel pump power control module whenever the engine is cranking or running. The control module enables the fuel pump power control module as long as the engine is cranking or running, and ignition system reference pulses are received. While this enable voltage is being received, the fuel pump power control module supplies a varying voltage to the in-tank fuel pump module in order to maintain the desired fuel line pressure.
Conditions for Running the DTC
* The ignition voltage is greater than 7 V.
* The DTC runs continuously when the condition above is met.
Conditions for Setting the DTC
* The ECM state of the fuel pump enable circuit does not match the state of the fuel pump enable circuit sensed by the fuel pump power control module.
* The above condition is met for 0.5 s.
Action Taken When the DTC Sets
DTC P12A6 is a Type A DTC.
Conditions for Clearing the DTC
DTC P12A6 is a Type A DTC.
Reference Information
Schematic Reference
Engine Controls Schematics (LUK) [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Sunshade - Left
Description and Operation
Fuel System Description Fuel System Description
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Verify that DTC P12A6 is not set.
• If the DTC is set
Refer to Circuit/System Testing
• If the DTC is not set
3. Command the Fuel Pump Enable ON and OFF with a scan tool.
4. Verify the following scan tool control circuit status parameters display OK:
* Fuel Pump Enable Circuit Low Voltage Test Status
* Fuel Pump Enable Circuit Open Test Status
* Fuel Pump Enable Circuit High Voltage Test Status
• If Malfunction is displayed
Refer to Circuit/System Testing
• If OK is displayed
5. 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.
6. Verify the DTC does not set.
• If the DTC sets
Refer to Circuit/System Testing
• If the DTC does not set
7. All OK.
Circuit/System Testing
1. Disconnect the K111 Fuel Pump Power Control Module harness connector.
2. Ignition OFF, and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down.
3. Test for 0 V on the enable circuit terminal 2 of the fuel pump power control module.
• If greater than 0 V
1. Ignition OFF, disconnect the harness connector at the K20 ECM.
2. Test for less than 1 V between the enable circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K20 ECM.
• If 0 V
4. Ignition ON, command the Fuel Pump Enable ON with a scan tool.
5. Test for B+ on the enable circuit terminal 2 of the fuel pump power control module.
• If less than B+
1. Ignition OFF, disconnect the harness connector at the K20 ECM.
2. Test for infinite resistance between the enable circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the enable circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 ECM.
• If B+
6. Replace the K111 Fuel Pump Power Control Module.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Fuel Pump Power Control Module Replacement Fuel Pump Power Control Module Replacement
* Control Module References Control Module References for ECM replacement, setup, and programming