Circuit/System Testing
WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
- 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
- Q17 Fuel Injector - Leaking/Restricted
- 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
- If the value does not change
- 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
- If the value does not change
- Test or replace the component: G18 High Pressure Fuel Pump