Diagnostic Test

WARNING: This page is about a different variant/trim than selected.

CHECK FOR AN ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, read DTCs and record on the repair order.
  Is the DTC active or pending?
  
  Yes
  - Go To 3
  No
  - Go To 2
MONITOR THE PRIMARY FUEL LEVEL SENSOR READING FOR AN OPEN SPOT ON THE SENSOR
WARNING:
The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released. Failure to follow these instructions can result in possible serious or fatal injury.
1. Disconnect the fuel supply line at the fuel rail.
2. Connect a drain hose between the fuel supply line and an approved fuel container.
3. Turn the ignition on.
4. Remove the Fuel Pump Relay from the PDC.
5. Connect a jumper across terminal 30 and terminal 87 of the Fuel Pump Relay connector to actuate the Fuel Pump Assembly until all fuel is removed from the Fuel Tank.
6. Remove the jumper when there is no more fuel coming out of the hose.
  NOTE:
  When the Fuel Tank is completely empty, the Primary Fuel Level Sensor should read at or near empty (indicated by a reading of approximately 94 ADC) on the scan tool. If the Fuel Tank is near full, the scan tool should read approximately 43 ADC on the scan tool.
  
  NOTE:
  Make sure that you have enough fuel to put back into the vehicle to make a good determination of the Fuel Level Sensor feedback. It may be necessary to add more fuel to what was removed in order to do so.
7. While monitoring the Primary Fuel Level Sensor reading on scan tool, begin putting fuel back into the Fuel Tank.
  NOTE:
  The Primary Fuel Level Sensor value should decrease as fuel is added at a steady rate. Watch for the value to change suddenly while fuel is being added. If the voltage suddenly changes it would indicate a bad spot (open) on that portion of the sensor.
  
  Did the Primary Fuel Level Sensor value suddenly change at any time while adding fuel?
  
  Yes
  - Replace the Primary Fuel Level Sensor in accordance with the Service Information. Refer to SENDING UNIT AND SENSOR, FUEL LEVEL, REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Perform the INTERMITTENT CONDITION test procedure. Refer to STANDARD PROCEDURE .
CHECK THE (N4) FUEL LEVEL SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Disconnect the Fuel Pump Module harness connector.
2. Measure the voltage on the (N4) Fuel Level Sensor Signal circuit at the Fuel Pump Module harness connector.
  Is the voltage above 5.0 volts?
  
  Yes
  - Repair the (N4) Fuel Level Sensor Signal circuit for a short to voltage.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 4
CHECK THE ABILITY OF THE PCM TO READ THE PRIMARY FUEL LEVEL SENSOR SIGNAL
1. Turn the ignition off.
2. Connect a jumper between the (N4) Fuel Level Sensor Signal circuit and the (G109) Fuel Level Sense Return circuit at the Fuel Pump Module harness connector.
3. Turn the ignition on.
4. With the scan tool, read DTCs.
  NOTE:
  The scan tool should display the DTC P0462-FUEL LEVEL SENSOR "A" CIRCUIT LOW as active or pending with the jumper in place.
  
  Does the scan tool display as describe above?
  
  Yes
  - Replace the Primary Fuel Level Sensor in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 5
CHECK THE (N4) FUEL LEVEL SENSOR SIGNAL CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the BCM C8 harness connector.
3. Measure the resistance of the (N4) Fuel Level Sensor Signal circuit between the Fuel Pump Module harness connector and the BCM C8 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (N4) Fuel Level Sensor Signal circuit for an open circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE (G109) FUEL LEVEL SENSE RETURN CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (G109) Fuel Level Sense Return circuit between the Fuel Pump Module harness connector and the BCM C8 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 7
  No
  - Repair the (G109) Fuel Level Sense Return circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK RELATED BCM AND COMPONENT CONNECTIONS
1. Perform any Service Bulletins that apply.
2. Disconnect all BCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
6. Reconnect all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace and program the Body Control Module in accordance with the Service Information. Refer to MODULE, BODY CONTROL (BCM), REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  - Test complete.