Circuit/System Testing
WARNING: This page is about a different car, the 2017 GMC Acadia. However, it is still accessible from the selected car via links, so may be relevant.
- Clear all DTCs.
- Road test the vehicle and perform a wide open acceleration from a stop until the transmission shifts into second gear. On manual transmission applications, shift to second gear or stop the test near 7, 000 RPM. Repeat the test at least three times.
- Verify the scan tool Fuel Rail Pressure Sensor parameter is between 14-17 MPa (2, 031-2, 466 PSI) while under load near 7, 000 RPM.
- If not between 14-17 MPa (2, 031-2, 466 PSI)
- Remove the G18 High Pressure Fuel Pump.
- Inspect the lobes on the camshaft for unusual wear.
- If the camshaft lobes are worn, replace the camshaft.
- If the camshaft lobes appear normal, test or replace the G18 High Pressure Fuel Pump.
- If between 14-17 MPa (2, 031-2, 466 PSI)
- Verify none of the conditions listed below exist:
- Contaminates in the fuel system, Refer to Alcohol/Contaminants-in-Fuel Diagnosis
- A Leak in the high pressure fuel system.
- A restricted fuel feed pipe between the G18 High Pressure Fuel Pump and the B47 Fuel Pressure Sensor.
- A leaking or restricted Q17 Fuel Injector, Refer to Fuel Injector Solenoid Coil Test , and Fuel Injector Balance Test .
- High resistance in the G18 High Pressure Fuel Pump actuator circuits.
- If a condition exist
Repair as necessary.
- If none of the conditions exist
- All OK.
NOTE:
Circuit/System Verification must be performed first or misdiagnosis may result.
WARNING:
Road test a vehicle under safe conditions and while obeying all traffic laws. Do not attempt any maneuvers that could jeopardize vehicle control. Failure to adhere to these precautions could lead to serious personal injury and vehicle damage.