Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Start the engine.
2. Allow the engine to reach normal operating temperature.
3. With the scan tool, select View DTCs and record on the repair order.
  NOTE:
  It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.
  
  Is the DTC Active or Pending at this time?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic Procedure. Refer to INTERMITTENT CONDITION .
CHECK FOR OTHER DTCS
1. Refer to the recorded DTCs.
  Are there any CAN BUS, communication or implausible signal DTCs active or pending or has DTC P0462 or P0463 set also?
  
  Yes
  - Perform the applicable diagnostic procedure(s). Refer to DIAGNOSTIC CODE INDEX .
  No
  - Go To 3
CHECK FOR FUEL LEVEL SENSOR CIRCUIT DTCS SET IN THE BCM
Are any Fuel Level Sensor Circuit DTCs set in the BCM?

Yes
- Diagnose the appropriate Fuel Level Sensor Circuit DTC in the BCM. Refer to DIAGNOSTIC CODE INDEX .
No
- Go To 4
VISUALLY CHECK FUEL TANK FOR DAMAGE
1. Visually inspect the Fuel Tank for damage that may restrict the Fuel Sending Unit float from moving.
  Is the Fuel Tank OK?
  
  Yes
  - Go To 5
  No
  - Replace the Fuel Tank as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (N4) FUEL LEVEL SIGNAL 1 CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Disconnect the Fuel Pump Module harness connector.
2. Disconnect the BCM C6 harness connector.
3. Measure the resistance of the (N4) Fuel Level Signal 1 circuit between the Fuel Pump Module harness connector and the BCM C6 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (N4) Fuel Level Signal 1 circuit for an open or high resistance.
  - 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 Signal Sense Return circuit between the Fuel Pump Module harness connector and the BCM C6 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 7
  No
  - Repair the (G109) Fuel Level Signal Sense Return circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK THE FUEL TANK AND FUEL PUMP MODULE FLOAT FOR DAMAGE OR OBSTRUCTIONS
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. Remove the Fuel Tank in accordance with the Service Information. Refer to TANK, FUEL, REMOVAL .
2. Remove the Fuel Pump Module. Refer to MODULE, FUEL PUMP, REMOVAL .
3. Visually inspect the inside of the Fuel Tank for any obstructions or deformities.
4. Inspect the Fuel Pump Module Float arm for damage.
  Were any problems found?
  
  Yes
  - Repair or replace as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 8
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. 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.
5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .