P0088

P0088-FUEL RAIL PRESSURE TOO HIGH





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Powertrain Control Module (PCM) will turn on the MIL lamp immediately after the diagnostic runs and fails. During this time the ETC lamp will also illuminate. The PCM will turn off the MIL lamp after the diagnostic runs and passes in four consecutive drive cycles.

- When Monitored:
Engine running.

- Set Condition:
Fuel pressure is above a calibrated value for a calibrated amount of time.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. OTHER DTCs
1. With the scan tool, read DTCs.

Are any other injector/fuel pressure related DTCs present?

Yes

- Troubleshoot other injector/fuel pressure related DTCs first.

No

- Go To 2

2. CHECK THE FUEL DELIVERY SYSTEM
1. Perform the CHECKING THE FUEL DELIVERY SYSTEM procedure. Checking The Fuel Delivery System

Did vehicle pass the CHECKING THE FUEL DELIVERY SYSTEM TEST?

Yes

- Go To 3

No

- Perform the appropriate repair.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

3. FUEL CONTROL ACTUATOR
1. Check for a mechanically stuck Fuel Control Actuator (FCA). Using the scan tool, actuate the Fuel Control Actuator.

NOTE: The Fuel Control Actuator will only click when cycled off.

Do you hear a click from the Fuel Control Actuator when you cycle the actuator off with the scan tool?

Yes

- Go To 4

No

- Replace the Fuel Control Actuator.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

4. CHECK VALVE DAMAGED OR BLOCKED
1. Check the fuel drain line check valve in the rear of the cylinder head for signs of damage, blockage, or debris.

Is the check valve damaged or blocked?

Yes

- Repair the cause of the damaged or blocked check valve or replace the valve.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 5

5. FUEL PRESSURE SENSOR
1. Using the scan tool, monitor the fuel pressure reading from the Fuel Rail Pressure Sensor at idle and at 2000 RPM.

Is the fuel rail pressure reading higher at 2000 RPM than at idle?

Yes

- Repair Complete.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Replace the Fuel Rail Pressure Sensor.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.