Circuit/System Testing
- Ignition OFF, remove the fuse that supplies B+ to terminal X2-56 of the ECM.
- Disconnect the X-406 harness connector at the rear of the fuel tank.NOTE: Testing for steps 3 - 7 is performed on the ECM side of the X-406 harness connector.
- Ignition OFF, test for less than 5 ohms between the low reference circuit terminal G and ground.
- If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit/connections test normal, replace the ECM.
- Install the fuse that supplies B+ to terminal X2-56 of the ECM.
- Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal E and ground.
- If less than the specified range, test the 5-volt reference circuit for a short to ground or open/high resistance. If the circuit/connections 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/connections test normal, replace the ECM.
- Verify the scan tool FTP Sensor parameter is less than 4.8 volts.
- If greater than the specified value, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.
- Install a 3A fused jumper wire between the signal circuit terminal F and the 5-volt reference circuit terminal E. Verify the scan tool FTP Sensor parameter is greater than 4.8 volts.
- If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the ECM.
- Remove the fuel tank. Refer to FUEL TANK REPLACEMENT (FWD) or FUEL TANK REPLACEMENT (AWD) .
- Disconnect the FTP sensor connector.
- Inspect the FTP sensor circuits in the fuel tank harness, between the FTP sensor connector and X- 406 for the following conditions, and repair as necessary:
- Damaged wiring or terminals
- Open circuits
- Short to ground
- Wire to wire short
- If all circuits/connections test normal, test or replace the FTP sensor.