Circuit/System Testing
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Fuel pressure control will be disable if DTC P0087, P0088, P0192, or P0193 are set. Codes must be cleared to enable the device control.
- Ignition OFF, disconnect the FRP sensor connector.
- Turn ON the ignition, with the engine OFF.
- Observe the Fuel Rail Pressure Sensor parameter with a scan tool The fuel pressure should be 200 MPa (29,000 psi).
- If the fuel pressure is 0 MPa (0 psi), test the FRP sensor signal circuit for a short to ground. If the circuit tests normal, replace the ECM.
- Probe the signal circuit terminal 2 with a test lamp connected to ground. The test lamp should not illuminate.
- If the test lamp illuminates, test the signal circuit for a short to voltage.
- Connect a fused jumper between the FRP signal circuit terminal 2 and the low reference circuit terminal 1 and observe the Fuel Rail Pressure Sensor parameter with a scan tool. The fuel pressure should be 0 MPa (0 psi).
- If the fuel pressure does not go to 0 MPa (0 psi), test the FRP sensor signal circuit and the low reference circuit for an open. If the circuit tests normal, replace the ECM.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.
- If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If all circuits test normal, replace the ECM.
- If greater than the specified range, test the 5-volt reference circuit for a short to voltage, If the circuit tests normal, replace the ECM.