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.
Fuel Pressure Low
- Verify none of the conditions listed below exist:
- Restricted fuel feed pipe
- Restricted or plugged strainer
- Poor connections at the fuel pump harness connector and the ground circuits
- If a condition exist
Repair as necessary.
- Go to next step: If a condition does not exist
- Replace the G12 Fuel Pump.
Fuel Pressure Leaks Down
- Open the valve on the CH - 37287 - 1A Fuel Pressure Gauge Adapter.
- Ignition ON, command the Fuel Pump Enable On with a scan tool.
- Close the valve on the CH - 37287 - 1A Fuel Pressure Gauge Adapter.
- Verify that the Fuel Pressure value on the CH-48027
Digital Fuel Pressure Gauge that is connected on the fuel rail side of the adaptor does not decrease greater than 34 kPa (5 PSI) in 1 minute.
- If the fuel pressure drops
Locate and replace the leaking Q17 Fuel Injector(s).
- Go to next step: If the fuel pressure does not drop
- If the fuel pressure drops
- Replace the G12 Fuel Pump.
Fuel Pressure Drops OFF
- Verify none of the conditions listed below exist:
- Restricted fuel feed pipe
- Restricted or plugged strainer
- Poor connections at the fuel pump harness connector and the ground circuit
- If a condition exist
Repair as necessary.
- Go to next step: If a condition does not exist
- Replace the G12 Fuel Pump.