26. Fuel System Leak Test

26. FUEL SYSTEM LEAK TEST

Purpose:
The purpose of this test is to check for fuel injector leakage. This test can also be run to check for an engine oil level increase due to leaks.

Fuel System Leak Test
- Carry out the Fuel System Leak Test.







Recommended Procedure:

NOTE:
- Verify the high pressure fuel system has no trapped air before continuing with this procedure. For additional information, refer to the Fuel Delivery and Air Induction, Fuel System.
- Do not carry out this test unless directed here from another procedure or DTC.
- Additional DTCs may result during this procedure.

NOTICE: While carrying out this procedure, at the first sign of a fuel leak immediately abort the test. Refer to the scan tool manufacturers manual for instructions.

- Bleed the high pressure fuel system. Refer to the Fuel Delivery and Air Induction Fuel System for the Fuel System Bleeding - High Pressure, Diesel Engine procedure. If air bubbles are present, complete the Fuel System Bleeding - High Pressure, Diesel Engine and retest. If the concern or DTC is still present continue with this test.
- Ignition ON, engine running.
- Access the PCM and monitor the RPM, FRP and FRP_DSD PIDs.
- Access the PCM and command the RPM to 1,500.
- Access the PCM and command the FRP_DSD to 169.96 MPa (24,650 PSI).
- Maintain the RPM and FRP_DSD for 10 minutes.
- Ignition in the OFF position.
- Allow the engine to remain OFF for 10 minutes.
- Check for the correct engine oil level using the oil level indicator with the vehicle on level ground.
- If entering this test directly from the Check Engine Oil Level test and the engine oil level increased, GO to Pinpoint Test AB to continue diagnosis. Test AB: Engine Oil Level Overfull
- If the engine oil level increased, carry out the High Pressure Fuel System Test With Valve Covers Off Running to continue diagnosis. 22. High Pressure Fuel System Test With Valve Covers Off Running
- If the engine oil level did not increase in this test and did not increase in the High Pressure Fuel System Test, refer to Symptom Charts, No Diagnostic Trouble Codes (DTCs) Present Symptom Chart Index and follow the diagnosis for Exhaust System Concerns. No Diagnostic Trouble Codes (DTCs) Present Symptom Chart Index

Tools Required:
Scan tool