Fuel Level Sensor Diagnostic Procedure
Note:Ensure that the ignition Switch is in the "OFF" position.
1. Remove the Rear Seat Cushion.
Lanos ONLY - Remove and retain the retaining bolt located at the front center of the Rear Seat Cushion, then lift up the front edge of the cushion to release the two (2) retaining latches.
Nubira & Leganza - Lift up on the front edge of the Rear Seat Cushion to release the two (2) retaining latches.
2. Remove the Rear Seat Bottom Cushion to gain access to the Fuel Tank.
3. Remove the Fuel Pump Module Access Cover.
4. Disconnect the Wiring Harness Electrical Connector from the Fuel Pump Module.
5. Turn the ignition switch to the "ON" position.
6. Using a suitable DVOM, measure voltage at the Wiring Harness Electrical Connector between terminal 1 and chassis ground. If a 5-V reference voltage is not present, repair the open circuit between terminal B5 of the ECM/PCM and the Wiring Harness Electrical Connector. If a 5-V reference voltage is present, go to the next step.
7. Measure the voltage at the Wiring Harness Electrical Connector between terminals 1 and 6. If a 5-V reference voltage is not present, repair the open circuit between terminal 6 of the Wiring Harness Electrical Connector and terminal D8 of the ECM/PCM. If a 5-V reference voltage is present, go to the next step.
8. Turn the Ignition Switch to the "OFF" position.
9. Reconnect the Wiring Harness Electrical Connector to the Fuel Pump Module.
10. Remove the Fuel Pump Relay from the Engine Compartment Fuse/Relay Box.
11. Start the engine and allow it to idle until the engine stalls. Crank the engine an additional 10 seconds, then turn the Ignition Switch to the "OFF" position.
Note:
The engine should stall in less than 10 seconds once Fuel Pump Relay is removed.
12. Remove the Fuel Filler Cap.
13. Disconnect the Fuel Outlet Hose from the Fuel Pump Module.
14. Disconnect the Fuel Tank Return Hose from the Fuel Pump Module.
15. Disconnect the Wiring Harness Electrical Connector.
16. Using a suitable hammer and brass drift, release the Fuel Pump Module Retaining Ring by rotating it counterclockwise.
17. After removing the Fuel Pump Module Retaining Ring, remove the Fuel Pump Module from the Fuel Tank.
CAUTION:
Removing components from a sealed fuel system exposes fuel vapors to outside oxygen and possible sources of combustion. A fuel system should only be opened in a properly ventilated area. Special caution should be used when removing components from a fuel tank or fuel system. Removal of such components should only be done away from open flame (torches, lit cigarettes, heater pilots or other flames however minor) or sparks (mechanical, electrical or otherwise) that could cause fuel vapors to ignite.
18. Reconnect the Wiring Harness Electrical Connector to the Fuel Pump Module.
19. Turn the Ignition Switch to the "ON" position.
20. Connect the Scan 100 Scan Tool to the vehicle Data-Link Connector (DLC) and go to the EVAP Data Screen to view the Fuel Level Sensor voltage
Screen Navigation Order:
Select "Diagnostic" >> Choose "model year" >> Choose "vehicle type" >> Select "Powertrain" >> Choose "transmission type" >> Select "Data Display" >> Select "Engine Data" >> Select "EVAP Data").
21. Slowly move the Fuel Level Sensor Float Arm from the "empty" position to the "full" position while observing the Fuel Level Sensor voltage indications on the Scan Tool EVAP Data Screen.
22. Confirm that the voltage makes a smooth transition from 0.7 to 2.7 volts.
23. If the voltage "dips" or "spikes," at any point throughout the voltage range, replace the Fuel Level Sensor.