Circuit/System Testing
NOTE:
Verify that the fuel tank is not empty. Only perform this diagnostic if there is at least 2 gallons of fuel in the fuel tank. Clear the DTC, and start and run the engine. Verify that the DTC resets before proceeding with the circuit system testing. If the DTC does not reset, refer to diagnostic aids.
- Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B47 Fuel Pressure Sensor. It may take up to 2 minutes for all vehicle systems to power down.
- Test for less than 10Ω between the low reference circuit terminal 2 and ground.
- If 10Ω or greater
- Ignition OFF, disconnect the harness connector at the K38 Chassis Control Module.
- Test for less than 2Ω in the low reference circuit end to end.
- If 2Ω or greater, repair the open/high resistance in the circuit.
- If less than 2Ω, replace the K38 Chassis Control Module.
- If less than 10Ω
- Ignition ON.
- Test for 4.8-5.2V between the 5V reference circuit terminal 3 and ground.
- If less than 4.8V
- Ignition OFF, disconnect the harness connector at the K38 Chassis Control Module.
- Test for infinite resistance between the 5V reference circuit and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2Ω in the 5V reference circuit end to end.
- If 2Ω or greater, repair the open/high resistance in the circuit.
- If less than 2Ω, replace the K38 Chassis Control Module.
- If greater than 5.2V
- Ignition OFF, disconnect the harness connector at the K38 Chassis Control Module, ignition ON.
- Test for less than 1V between the 5V reference circuit and ground.
- If 1V or greater, repair the short to voltage on the circuit.
- If less than 1V, replace the K38 Chassis Control Module.
- If between 4.8-5.2V
- Verify the scan tool Fuel Pressure Sensor Voltage parameter is less than 1V.
- If 1V or greater
- Ignition OFF, disconnect the harness connector at the K38 Chassis Control Module, ignition ON.
- Test for less than 1V between the signal circuit terminal 1 and ground.
- If 1V or greater, repair the short to voltage on the circuit.
- If less than 1V, replace the K38 Chassis Control Module.
- If less than 1V
- Install a 3A fused jumper wire between the signal circuit terminal 1 and the 5V reference circuit terminal 3, wait 15 seconds.
- Verify the scan tool Fuel Pressure Sensor Voltage parameter is greater than 4.8V.
- If 4.8V or less
- Ignition OFF, disconnect the harness connector at the K38 Chassis Control Module.
- Test for infinite resistance between the signal circuit terminal 1 and ground.
- If less than infinite resistance, repair the short to ground on the circuit.
- If infinite resistance
- Test for less than 2Ω in the signal circuit end to end.
- If 2Ω or greater, repair the open/high resistance in the circuit.
- If less than 2Ω, replace the K38 Chassis Control Module.
- If greater than 4.8V
- Test or replace the B47 Fuel Pressure Sensor.