Diagnostic Test
WARNING: This page is about a different car, the 2009 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.
- 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.
- Turn the ignition on, then off, and then on again.
- 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
- Diagnose and repair the DTC. See DTC-Based Diagnostics/MODULE, Occupant Classification (OCM) - Diagnosis and Testing for a complete list of DTCs.
No
- Go to step 2
- PREFORM OCM VERIFICATION NOTE: Failure to follow the test instructions or aborting the test causes faults to set when performing the Occupant Classification Module System Verification Test. To prevent faults due to process errors: verify that all tests steps that led you here were performed as directed, verify that the ignition is in run. Wait 30 seconds after changing the seat weight before proceeding to allow the system to stabilize. Only press scan tool buttons when directed to do so and perform the Occupant Classification Module System Verification Test to completion.
- With the scan tool in OCM, select More Options, select System Tests, and select Occupant Classification Module System Verification Test. Run the test by following the instructions displayed on the scan tool. When the test is complete, wait two minutes, and then proceed as follows.
- 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 DTC?
Yes
- Go to step 3
No
- Perform the OCS VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Occupant Classification (OCM) - Standard Procedure .
- VERIFY SENSOR IS TIGHTENED TO SPECIFICATION
- Verify that all of the Seat Weight Sensor mounting screws are tightened to specification. Refer to Restraints - Specifications
for specification.NOTE: Failure to follow the test instructions or aborting the test causes faults to set when performing the Occupant Classification Module System Verification Test. To prevent faults due to process errors: verify that all tests steps that led you here were performed as directed, verify that the ignition is in run. Wait 30 seconds after changing the seat weight before proceeding to allow the system to stabilize. Only press scan tool buttons when directed to do so and perform the Occupant Classification Module System Verification Test to completion.
- With the scan tool in OCM, select More Options, select System Tests, and select Occupant Classification Module System Verification Test. Run the test by following the instructions displayed on the scan tool. When the test is complete, wait two minutes, and then proceed as follows.
- 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 DTC?
Yes
- Go to step 4
No
- Perform the OCS VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Occupant Classification (OCM) - Standard Procedure .
- Verify that all of the Seat Weight Sensor mounting screws are tightened to specification. Refer to Restraints - Specifications
for specification.
- 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.
- 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.
Are any of these conditions present?
Yes
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.- Replace the Passenger Seat Harness in accordance with the Service Information.
- Perform the RE-ZERO OCM SEAT WEIGHT SENSORS diagnostic procedure. See DTC-Based Diagnostics/MODULE, Occupant Classification (OCM) - Standard Procedure .
No
- Go to step 5
- 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.
- VERIFY THAT PASSENGER SEAT HARNESS IS ROUTED CORRECTLY
- Verify that the Passenger Seat Harness is routed correctly.
Is the Passenger Seat Harness routed correctly?
Yes
- Go to step 6
No
- Reroute the Passenger Seat Harness as necessary.
- Perform the RE-ZERO OCM SEAT WEIGHT SENSORS diagnostic procedure. See DTC-Based Diagnostics/MODULE, Occupant Classification (OCM) - Standard Procedure .
- Verify that the Passenger Seat Harness is routed correctly.
- CHECK (R717) LT-FT SEAT WEIGHT SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
Courtesy of CHRYSLER LLC
- Disconnect the OCM C2 harness connector.
- Measure the voltage of the (R717) LT-FT Seat Weight Sensor Signal circuit.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 voltage above 0.2 of a volt?
Yes
- Replace the Passenger Seat Harness in accordance with the Service Information.
- Perform the RE-ZERO OCM SEAT WEIGHT SENSORS diagnostic procedure. See DTC-Based Diagnostics/MODULE, Occupant Classification (OCM) - Standard Procedure .
No
- Go to step 7
- CHECK (R717) LT-FT SEAT WEIGHT SENSOR SIGNAL CIRCUIT FOR A SHORT TO (R701) SEAT WEIGHT SENSOR 5-VOLT CIRCUIT Fig 2: Measuring Resistance Between Left-Front Seat Weight Sensor Signal Circuit & Seat Weight Sensor 5-Volt Circuit.
Courtesy of CHRYSLER LLC
- Disconnect the Left-Front Seat Weight Sensor connector.
- Measure the resistance between the (R717) LT-FT Seat Weight Sensor Signal circuit and the (R701) Seat Weight Sensor 5-volt circuit.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. See DTC-Based Diagnostics/MODULE, Occupant Classification (OCM) - Standard Procedure .
No
- Go to step 8
- CHECK (R728) SEAT WEIGHT SENSOR GROUND CIRCUIT FOR AN OPEN
- Measure the resistance of the (R728) Seat Weight Sensor Ground 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: 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. See DTC-Based Diagnostics/MODULE, Occupant Classification (OCM) - Standard Procedure .
No
- Replace the Passenger Seat Harness in accordance with the Service Information.
- Perform the RE-ZERO OCM SEAT WEIGHT SENSORS diagnostic procedure. See DTC-Based Diagnostics/MODULE, Occupant Classification (OCM) - Standard Procedure .
- Measure the resistance of the (R728) Seat Weight Sensor Ground circuit between the OCM C2 connector and the Left-Front Seat Weight Sensor connector.