Diagnostic Test

WARNING: This page is about a different car, the 2015 Fiat 500. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, clear all DTCs.
3. With the scan tool, read DTCs.
  Does the scan tool display this DTC as active?
  
  Yes
  - Go To 2
  No
  - Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
CHECK THE (N4) FUEL LEVEL SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the Fuel Pump Module C1 harness connector.
3. Disconnect the BCM C2 harness connector.
4. Turn the ignition on.
5. Measure the voltage between ground and the (N4) Fuel Level Sensor Signal circuit at the Fuel Pump Module harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the short to voltage in the (N4) Fuel Level Sensor Signal circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
  No
  - Go To 3
CHECK THE FUEL LEVEL SENSOR FOR CORRECT OPERATION
1. Turn the ignition off.
2. Connect the BCM C2 harness connector.
3. Connect a jumper wire between the (N4) Fuel Level Sensor Signal circuit and the (G109) Fuel Level Sense Return circuit at the Fuel Pump Module harness connector.
4. Turn the ignition on.
5. With the scan tool, read DTCs.
  Does the scan tool display DTC: B1006-11-FUEL LEVEL SENSOR - CIRCUIT SHORT TO GROUND?
  
  Yes
  - Replace the Fuel Level Sending Unit in accordance with the Service Information. Refer to MODULE, FUEL PUMP, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
  No
  - Go To 4
CHECK THE (G109) FUEL LEVEL SENSE RETURN CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the BCM C2 harness connector.
3. Measure the resistance of the (G109) Fuel Level Sense Return circuit between the Fuel Pump Module harness connector and the BCM C2 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the open in the (G109) Fuel Level Sense Return circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
BODY CONTROL MODULE (BCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Pump Module and the BCM.
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Fuel Pump Module and the BCM harness connectors.
4. Perform any Technical Service Bulletins (TSB)s that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .
  No
  - Replace the BCM in accordance with the Service Information. Refer to MODULE, BODY CONTROL, REMOVAL .
  - Perform the BODY VERIFICATION TEST. Refer to BODY CONTROL MODULE (BCM) - BODY VERIFICATION TEST - 500 - EXCEPT ELECTRIC .