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Diagnostic Test

WARNING: This page is about a different car, the 2011 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK FOR ACTIVE INTERNAL FAULTS, IGNITION FAULTS, AND BATTERY FAULTS IN THE OCCUPANT CLASSIFICATION MODULE (OCM) 
    NOTE:

    Make sure that the battery is fully charged.

    1. Turn the ignition on, then off, and then on again.
    2. With the scan tool, read Occupant Classification Module (OCM) DTCs.

      Does the scan tool display any active DTCs relating to internal faults, ignition faults, or battery faults?

      Yes 

      No 

      • Go To  2.
  2. VERIFY THAT DTC B1B79-PASSENGER SEAT WEIGHT SENSOR 3 - LEFT FRONT INPUT CIRCUIT LOW IS ACTIVE 
    1. With the scan tool, read the OCM DTCs.

      Does the scan tool display active B1B79-PASSENGER SEAT WEIGHT SENSOR 3 - LEFT FRONT INPUT CIRCUIT LOW DTC?

      Yes 

      • Go To  3.

      No 

  3. VERIFY THAT B1B7A-PASSENGER SEAT WEIGHT SENSOR 3 - LEFT FRONT INPUT CIRCUIT HIGH DTC AND B1B79-PASSENGER SEAT WEIGHT SENSOR 3 - LEFT FRONT INPUT CIRCUIT LOW DTC ARE ACTIVE AT THE SAME TIME 
    1. With the scan tool, read the OCM DTCs.

      Does the scan tool display active B1B7A-PASSENGER SEAT WEIGHT SENSOR 3 - LEFT FRONT INPUT CIRCUIT HIGH AND B1B79-PASSENGER SEAT WEIGHT SENSOR 3 - LEFT FRONT INPUT CIRCUIT LOW DTC AT THE SAME TIME?

      Yes 

      • Refer to Diagnosis and Testing  and perform the B1B79-PASSENGER SEAT WEIGHT SENSOR 3 - LEFT FRONT INPUT CIRCUIT HIGH diagnostic procedure.

      No 

      • Go To  4.
  4. INSPECT PASSENGER SEAT HARNESS WIRES AND CONNECTORS 
    WARNING:

    Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

    1. Using the wiring diagram / schematic as a guide, inspect the Passenger Seat Harness wiring and connectors. Look for chafed, pierced, pinched, or partially broken wires and broken, bent, pushed out, spread, corroded, or contaminated terminals.
      NOTE:

      Do not attempt to repair the Seat Harness. Replace the Seat Harness if the condition inspecting or testing for is present in the Seat Harness.

      Are any of these conditions present?

      Yes 

      • Replace the Passenger Seat Harness in accordance with the Service Information.
      • Perform the RE-ZERO OCM SEAT WEIGHT SENSORS diagnostic procedure. Refer to RE-ZERO OCM SEAT WEIGHT SENSORS .

      No 

      • Go To  5.
  5. VERIFY THAT PASSENGER SEAT HARNESS IS ROUTED CORRECTLY 
    1. Verify that the Passenger Seat Harness is routed correctly.

      Is the Passenger Seat Harness routed correctly?

      Yes 

      • Go To  6.

      No 

      • Reroute the Passenger Seat Harness as necessary.
      • Perform the RE-ZERO OCM SEAT WEIGHT SENSORS diagnostic procedure. Refer to RE-ZERO OCM SEAT WEIGHT SENSORS .
  6. CHECK VOLTAGE OF (R701) SEAT WEIGHT SENSOR 5-VOLT CIRCUIT 
    Fig 1: Measuring Voltage Of Seat Weight Sensor 5-Volt Circuit
    GC0101792Courtesy of CHRYSLER LLC
    1. Disconnect the Left-Front Seat Weight Sensor connector.
      WARNING:

      Turn the ignition on, then reconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

    2. Measure the voltage of the (R701) Seat Weight Sensor 5-volt circuit.

      Is the voltage above 4.8 volts?

      Yes 

      • Go To  7.

      No 

      • Go To  9.
  7. CHECK (R717) LT-FT SEAT WEIGHT SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND 
    Fig 2: Checking Left-Front Seat Weight Sensor Signal Circuit For Short To Ground
    GC0101793Courtesy of CHRYSLER LLC
    WARNING:

    Turn the ignition off disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

    1. Disconnect the OCM C2 connector.
    2. Measure the resistance of the (R717) LT-FT Seat Weight Sensor Signal circuit between ground and the OCM C2 connector.
      NOTE:

      Do not attempt to repair the Seat Harness. Replace the Seat Harness if the condition inspecting or testing for is present in the Seat Harness.

      Is the resistance below 5.0 Ohms?

      Yes 

      • Replace the Passenger Seat Harness in accordance with the Service Information.
      • Perform the RE-ZERO OCM SEAT WEIGHT SENSORS diagnostic procedure. Refer to RE-ZERO OCM SEAT WEIGHT SENSORS .

      No 

      • Go To  8.
  8. CHECK (R717) LT-FT SEAT WEIGHT SENSOR SIGNAL CIRCUIT FOR AN OPEN 
    Fig 3: Checking Left-Front Seat Weight Sensor Signal Circuit For An Open
    GC0101794Courtesy of CHRYSLER LLC
    1. Measure the resistance of the (R717) LT-FT Seat Weight Sensor Signal circuit between the OCM C2 connector and the Left-Front Seat Weight Sensor connector.
      NOTE:

      Do not attempt to repair the Seat Harness. Replace the Seat Harness if the condition inspecting or testing for is present in the Seat Harness.

      Is the resistance below 5.0 Ohms?

      Yes 

      • Replace the Left-Front Seat Weight Sensor in accordance with the Service Information.
      • Perform the RE-ZERO OCM SEAT WEIGHT SENSORS diagnostic procedure. Refer to RE-ZERO OCM SEAT WEIGHT SENSORS .
      • If DTC B1B79-PASSENGER SEAT WEIGHT SENSOR 3 - LEFT FRONT INPUT CIRCUIT LOW returns active, Go To  10.

      No 

      • Replace the Passenger Seat Harness in accordance with the Service Information.
      • Perform the RE-ZERO OCM SEAT WEIGHT SENSORS diagnostic procedure. Refer to RE-ZERO OCM SEAT WEIGHT SENSORS .
  9. CHECK (R701) SEAT WEIGHT SENSOR 5-VOLT CIRCUIT FOR AN OPEN 
    Fig 4: Checking Seat Weight Sensor 5-Volt Circuit For An Open
    GC0101795Courtesy of CHRYSLER LLC
    WARNING:

    Turn the ignition off disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

    1. Disconnect the OCM connectors.
    2. Measure the resistance of the (R701) Seat Weight Sensor 5-volt circuit between the OCM C2 connector and the Left-Front Seat Weight Sensor connector.
      NOTE:

      Do not attempt to repair the Seat Harness. Replace the Seat Harness if the condition inspecting or testing for is present in the Seat Harness.

      Is the resistance below 5.0 Ohms?

      Yes 

        WARNING:

        Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

      • Replace the OCM in accordance with the Service Information.
      • Perform the RE-ZERO OCM SEAT WEIGHT SENSORS diagnostic procedure. Refer to RE-ZERO OCM SEAT WEIGHT SENSORS .

      No 

      • Replace the Passenger Seat Harness in accordance with the Service Information.
      • Perform the RE-ZERO OCM SEAT WEIGHT SENSORS diagnostic procedure. Refer to RE-ZERO OCM SEAT WEIGHT SENSORS .
  10. REPLACE THE OCCUPANT CLASSIFICATION MODULE 
    WARNING:

    Turn the ignition off, disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

    View repair

    Repair 

      WARNING:

      If the Occupant Classification Module (OCM) is dropped at any time, it must be replaced. Failure to take the proper precautions could result in accidental airbag deployment and may result in possible serious or fatal injury.

    • Replace the OCM in accordance with the Service Information.
    • Perform the RE-ZERO OCM SEAT WEIGHT SENSORS diagnostic procedure. Refer to RE-ZERO OCM SEAT WEIGHT SENSORS .
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