Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.

NOTE:

You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

Verify there are no fuel system leaks. Refer to Fuel Leak Diagnosis .
- If a fuel leak is found
  Repair as necessary.
- Go to next step: If a fuel leak is not found
Engine cranking or running, verify scan tool parameter Fuel Pressure Sensor is between 370-450 kPa (54-65 PSI).
- If not within 370-450 kPa (54-65 PSI)
  Refer to Fuel System Diagnosis for further diagnosis.
- Go to next step: If within 370-450 kPa (54-65 PSI)
Verify that no fuel injector nozzles are stuck in the open position. Refer to Fuel Injector Balance Test with Scan Tool and perform the procedure under Circuit/System Testing.
- If a fuel injector nozzle is stuck open
  Replace the appropriate Q17 Fuel Injector.
- Go to next step: If a fuel injector nozzle is not stuck open
Perform the scan tool control function: Fuel Pressure Control - Regulator 1 - Increase & Decrease
Verify the scan tool parameter: Fuel Rail Pressure Sensor 1 = The value should change with each command.
- If the value does not change
  Replace the component: Q18A Fuel Pressure Regulator 1
- If the value changes
Perform the scan tool control function: Fuel Pressure Control - Regulator 2 - Increase & Decrease
Verify the scan tool parameter: Fuel Rail Pressure Sensor 1 = The value should change with each command.
- If the value does not change
  Replace the component: Q18B Fuel Pressure Regulator 2
- If the value changes
All OK.