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P00CA




DTC P00C9 or P00CA

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 P00C9
- Fuel Pressure Regulator 1 High Control Circuit Low Voltage

DTC P00CA
- Fuel Pressure Regulator 1 High Control Circuit High Voltage

Diagnostic Fault Information






Typical Scan Tool Data










Circuit/System Description

The engine control module (ECM) controls the fuel rail pressure by controlling fuel pressure regulator 1 and fuel pressure regulator 2 simultaneously to achieve the desired fuel rail pressure. Fuel pressure regulator 1 is located on the fuel injection pump and controls the amount of fuel allowed into the high pressure side of the injection pump. If the ECM detects a fault on either of the fuel pressure regulator 1 circuits a DTC will be set.

Conditions for Running the DTC

* Engine speed is greater than 600 RPM.
* Battery voltage is greater than 11 V.

Conditions for Setting the DTC

DTC P00C9
* The ECM detects low voltage on the supply voltage circuit of fuel pressure regulator 1.
* The above condition exists for greater than 1 s.

DTC P00CA
* The ECM detects high voltage on the supple voltage circuit of fuel pressure regulator 1.
* The above condition exists for greater than 1 s.

Action Taken When the DTC Sets

* DTC's P00C9 and P00CA are Type A DTCs
* The ECM commands the engine to operate in the Reduced Engine Power mode.
* The message center displays Engine Power Is Reduced.

Conditions for Clearing the DTC

DTC's P00C9 and P00CA are Type A DTCs

Diagnostic Aids

* No driveabilty concerns may be present if the fuel pressure regulator 1 supply voltage circuit is shorted to voltage.
* If the fuel system pressure is actually too high, a fuel knock condition may exist.

Reference Information
Schematic Reference

Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)
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. Engine Running, observe the following scan tool parameters:

* Fuel Press. Reg. 1 Ctrl. Ckt. Short to Gnd Test Status
* Fuel Press. Reg. 1 Ctrl. Ckt. Open Test Status
* Fuel Press. Reg. 1 High Ctrl. Ckt. Short Gnd Test Status
* Fuel Press. Reg. 1 High Ctrl. Ckt. Short Volts Test Status
Each parameter should display OK or Not Run.

2. Engine Running, verify the difference between the Actual Fuel Rail Pressure and the Desired Fuel Rail Pressure parameter is less than 5 MPa (725 psi).
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

1. Ignition OFF, disconnect the 12-way harness connector at the engine harness jumper. Refer to Inline Harness Connector End Views X100
Note: Testing for steps 2-7 is performed on the ECM side of the harness connector.

2. Connect a test lamp between the high control circuit terminal 5 and ground.
3. Ignition ON, verify the test lamp illuminates for 1-2 s and then turns OFF.

• If the test lamp does not illuminate , test the high control circuit for an open, high resistance or short to ground. If the circuit tests normal, replace the K20 engine control module.
• If the test lamp remains illuminated , test the high control circuit for a short to B+. If the circuit tests normal, replace the K20 engine control module.

4. Ignition ON, verify that a test lamp does not illuminate between the low control circuit terminal 6 and ground.

• If the test lamp illuminates, test the low control circuit for a short to voltage. If the circuit tests normal, replace the K20 engine control module.

5. Ignition OFF, ECM powered down. Connect a test lamp between the low control circuit terminal 6 and B+.
6. Ignition ON, verify the test lamp illuminates.

• If the test lamp does not illuminate, test the low control circuit for an open or high resistance. If the circuit tests normal, replace the K20 engine control module.

7. Ignition OFF, Observe that the test lamp flashes 2 times and remains OFF until the ECM is powered down.

• If the test lamp does not flash 2 times and turn OFF, test the low control circuit for a short to ground. If the circuit tests normal, replace the K20 engine control module.

Note: Testing for this step is performed on the engine side of the harness connector.

8. Disconnect the harness connector at the Q45A fuel pressure regulator 1. Test, inspect and repair the items listed below. If all items test normal, replace the Q45A fuel pressure regulator 1.

* Poor connection at the Q45A fuel pressure regulator 1,
* Open, high resistance or shorted fuel pressure regulator 1 high control circuit.
* Open, high resistance or shorted fuel pressure regulator 1 low control circuit.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Fuel Pressure Regulator Replacement Service and Repair
* Perform the scan tool Diesel Particulate Filter (DPF) Regeneration Enable Diesel Particulate Filter (DPF) Regeneration Enable procedure if the scan tool DPF Soot Mass is less than 30 g. If the scan tool DPF Soot Mass is 30 g or greater, perform the Diesel Particulate Filter (DPF) Service Regeneration Diesel Particulate Filter (DPF) Service Regeneration procedure.
* Control Module References Control Module References for ECM replacement, programming, and setup.

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