Diagnostic Test

WARNING: This page is about a different car, the 2016 Jeep Wrangler and 2015 Jeep Wrangler. However, it is still accessible from the selected car via links, so may be relevant.

ACTIVE DTC
NOTE:
Diagnose any CAN Communication DTCs before continuing.
1. Start the engine.
2. Allow the engine to reach normal operating temperature.
3. With a scan tool, read DTCs and record the related Freeze Frame data.
  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 at this time?
  
  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.
CHECK THE FUEL LEVEL SENSOR

Fig 1: Fuel Pump Module Electrical Harness Connector
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Disconnect the Fuel Pump Module harness connector.
3. Ignition on, engine not running.
4. Using a fused jumper wire, jumper the (K91) Sensor Ground circuit to the (N4) Fuel Level Sensor Signal circuit in the Fuel Pump Module harness connector.
  Did the Fuel gauge level change from empty to full?
  
  Yes
  - Verify that there is good pin to terminal contact at the Fuel Pump Module, and the Totally Integrated Power Module connectors. If OK, replace the Fuel Level Sensor/Fuel Pump Module.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (N4) FUEL LEVEL SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND

Fig 2: Checking Fuel Level Signal Circuit For Short To Ground
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Disconnect the TIPM C7 harness connector.
3. Measure the resistance between ground and the (N4) Fuel Level Sensor Signal circuit in the Fuel Pump Module harness connector.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the short to ground in the (N4) Fuel Level Sensor Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (N4) FUEL LEVEL SENSOR SIGNAL CIRCUIT FOR AN OPEN

Fig 3: Measuring Resistance Of Fuel Level Signal Circuit
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off.
2. Measure the resistance of the (N4) Fuel Level Sensor Signal circuit from the Fuel Pump Module harness connector to the TIPM C7 harness connector.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the open in the (N4) Fuel Level Sensor Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (N4) FUEL LEVEL SENSOR SIGNAL CIRCUIT FOR A SHORT TO THE (K91) SENSOR GROUND CIRCUIT

Fig 4: Measuring Resistance Between Fuel Level Signal Circuit And Switch Return Circuit From Fuel Pump Module Harness Connector
Courtesy of CHRYSLER GROUP, LLC
1. Disconnect the TIPM C1 harness connector.
2. Measure the resistance between the (N4) Fuel Level Sensor Signal circuit and the (K91) Sensor Ground circuit in the Fuel Pump Module harness connector.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the short between the (K91) Sensor Ground circuit and the (N4) Fuel Level Sensor Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
TOTALLY INTEGRATED POWER MODULE (TIPM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Fuel Pump Module and the Totally Integrated Power Module (TIPM).
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 TIPM connectors.
4. Perform any Technical Service Bulletins that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace the Totally Integrated Power Module in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to STANDARD PROCEDURE .