Circuit/System Testing

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

Ignition/Vehicle - Off
Verify the following conditions do not exist :
- Q17 Fuel Injector - Leaking/Restricted
  Refer to : Fuel Injector Balance Test
- Direct Fuel Injection Fuel Rail - Leaking/Restricted
  Refer to : Fuel Leak Diagnosis
- Fuel - Contaminated/Poor Quality
  Refer to : Contaminants-in-Fuel Diagnosis
- Fuel Feed Pipe - Leaking/Restricted
  Refer to : Fuel Leak Diagnosis
- If a condition exists
  Repair or replace as necessary
- Go to next step : If no condition exists
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
- Go to next step : 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
- Go to next step : If the value changes
Test or replace the component : G18 High Pressure Fuel Pump