Circuit/System Testing

WARNING: This page is about a different car, the 2018 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.

Fuel Pressure Low

Verify none of the conditions listed below exist:
- Restricted or dislocated fuel feed front pipe check valve
- Restricted fuel feed pipe
- Inspect the harness connectors and the ground circuits of the fuel pump for poor connections.
- If a condition exists
  Repair as necessary.
- Go to next step: If no conditions exist
  Go to next step: Replace the G12 Fuel Pump.

Fuel Pressure Leaks Down

Ignition OFF, relieve the fuel pressure. Refer to Fuel Pressure Relief .
Install the EN-37287 between the chassis fuel feed hose and the engine compartment fuel feed pipe.
Open the valve on the EN-37287 .
Ignition ON, command the Fuel Pump Enable On and then Off with a scan tool.
Close the valve on the EN-37287 .
Verify that the scan tool Fuel Pressure Sensor parameter does not decrease more than 34 kPa (5 PSI) in 1 min.
- If greater than 34 kPa (5 PSI)
  Replace the G12 Fuel Pump.
- Go to next step: If less than 34 kPa (5 PSI)
Test for a faulty fuel feed front pipe check valve.
- If a condition exists
  Replace the fuel feed front pipe.
- Go to next step: If no condition exists
Test for a leaking G18 High Pressure Fuel Pump.
- If a condition exists
  Replace the G18 High Pressure Fuel Pump.
- Go to next step: If no condition exists
  Go to next step: Locate and replace the leaking Q17 Fuel Injector.

Fuel Pressure Drops Off

Verify none of the conditions listed below exist:
- Restricted or dislocated fuel feed front pipe check valve
- Restricted fuel feed pipe
- Inspect the harness connectors and the ground circuits of the fuel pump for poor connections.
- If a condition exists
  Repair as necessary.
- Go to next step: If no conditions exist
  Go to next step: Replace the G12 Fuel Pump.