Diagnostic Test

WARNING: This page is about a different car, the 2006 Chrysler PT Cruiser. 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: Ensure 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
1. Diagnose and repair the DTCs. Refer to the DTCS B1203 TO B1B19 & DIAGNOSTIC CODE INDEX article, and other appropriate DIAGNOSTICS articles.
No
1. Go To 2).
2) VERIFY THAT DTC B1B88-PASSENGER SEAT WEIGHT SENSOR 1 - RIGHT REAR INPUT CIRCUIT LOW IS ACTIVE
With the scan tool, read OCM DTCs.

Does the scan tool display active: B1B88-PASSENGER SEAT WEIGHT SENSOR 1 - RIGHT REAR INPUT CIRCUIT LOW?

Yes
1. Go To 3).
No
1. Go To 10).
3) VERIFY THAT DTC B1B88-PASSENGER SEAT WEIGHT SENSOR 1 - RIGHT REAR INPUT CIRCUIT LOW AND B1B89-PASSENGER SEAT WEIGHT SENSOR 1 - RIGHT REAR INPUT CIRCUIT HIGH ARE ACTIVE AT THE SAME TIME
With the scan tool, read OCM DTCs.

Does the scan tool display active: B1B88-PASSENGER SEAT WEIGHT SENSOR 1 - RIGHT REAR INPUT CIRCUIT LOW DTC AND B1B89-PASSENGER SEAT WEIGHT SENSOR 1 - RIGHT REAR INPUT CIRCUIT HIGH DTC AT THE SAME TIME?

Yes
1. Perform the B1B89-PASSENGER SEAT WEIGHT SENSOR 1 - RIGHT REAR INPUT CIRCUIT HIGH diagnostic test.
No
1. Go To 4).
4) INSPECT PASSENGER SEAT HARNESS WIRES AND CONNECTORS
WARNING: To avoid personal injury or death, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

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 any of these conditions exist.
1. Replace the Passenger Seat Harness in accordance with the Service Information.
2. Perform the *OCCUPANT CLASSIFICATION MODULE SYSTEM VERIFICATION TEST .
3. Perform the *AIRBAG SYSTEM VERIFICATION TEST - VER 1 .
No
1. Go To 5).
5) 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
1. Go To 6).
No
1. Reroute the Passenger Seat Harness as necessary.
2. Perform the *OCCUPANT CLASSIFICATION MODULE SYSTEM VERIFICATION TEST .
3. Perform the *AIRBAG SYSTEM VERIFICATION TEST - VER 1 .
6) CHECK VOLTAGE OF (R701) SEAT WEIGHT SENSOR 5 VOLT CIRCUIT

Fig 1: CHECKING VOLTAGE OF SEAT WEIGHT SENSOR 5 VOLT CIRCUIT
Courtesy of DAIMLERCHRYSLER CORP.

WARNING: To avoid personal injury or death, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

Disconnect the Right-Rear Seat Weight Sensor connector.

WARNING: To avoid personal injury or death, turn the ignition on, then reconnect the battery.

Measure the voltage of the (R701) Seat Weight Sensor 5 Volt circuit.

Is the voltage above 4.8 volts?

Yes
1. Go To 7).
No
1. Go To 9).
7) CHECK (R706) RT-RR SEAT WEIGHT SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND

Fig 2: Checking Right Rear Passenger Seat Weight Sensor Signal Circuit
Courtesy of DAIMLERCHRYSLER CORP.

WARNING: To avoid personal injury or death, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

Disconnect the OCM C2 connector.

Measure the resistance of the (R706) RT-RR Seat Weight Sensor Signal circuit between ground and the OCM C2 connector.

Is the resistance below 10k ohms?

Yes

NOTE: Do not attempt to repair the Seat Harness. Replace the Seat Harness if any of these conditions exist.
1. Replace the Passenger Seat Harness in accordance with the Service Information.
2. Perform the *OCCUPANT CLASSIFICATION MODULE SYSTEM VERIFICATION TEST .
3. Perform the *AIRBAG SYSTEM VERIFICATION TEST - VER 1 .
No
1. Go To 8).
8) CHECK (R706) RT-RR SEAT WEIGHT SENSOR SIGNAL CIRCUIT FOR AN OPEN

Fig 3: CHECKING RT-RR SEAT WEIGHT SENSOR SIGNAL CIRCUIT FOR AN OPEN
Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance of the (R706) RT-RR Seat Weight Sensor Signal circuit between the OCM C2 connector and the Right-Rear Seat Weight Sensor connector.

Is the resistance below 5.0 ohms?

Yes
1. Replace the Right-Rear Seat Weight Sensor in accordance with the Service Information.
2. Perform the *OCCUPANT CLASSIFICATION MODULE SYSTEM VERIFICATION TEST .
3. Perform the *AIRBAG SYSTEM VERIFICATION TEST - VER 1 . If DTC B1B88-PASSENGER SEAT WEIGHT SENSOR 1 - RIGHT REAR INPUT CIRCUIT LOW returns active, replace the OCM in accordance with the Service Information..
No

NOTE: Do not attempt to repair the Seat Harness. Replace the Seat Harness if any of these conditions exist.
1. Replace the Passenger Seat Harness in accordance with the Service Information.
2. Perform the *OCCUPANT CLASSIFICATION MODULE SYSTEM VERIFICATION TEST .
3. Perform the *AIRBAG SYSTEM VERIFICATION TEST - VER 1 .
9) CHECK (R701) SEAT WEIGHT SENSOR 5 VOLT CIRCUIT FOR AN OPEN

Fig 4: CHECKING SEAT WEIGHT SENSOR 5 VOLT CIRCUIT FOR AN OPEN
Courtesy of DAIMLERCHRYSLER CORP.

WARNING: To avoid personal injury or death, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

Disconnect the OCM connectors.

Measure the resistance of the (R701) Seat Weight Sensor 5 Volt circuit between the OCM C2 connector and the Right-Rear Seat Weight Sensor connector.

Is the resistance below 5.0 ohms?

Yes
1. Replace the OCM in accordance with the Service Information.
2. Perform the *OCCUPANT CLASSIFICATION MODULE SYSTEM VERIFICATION TEST .
3. Perform the *AIRBAG SYSTEM VERIFICATION TEST - VER 1 .
No

NOTE: Do not attempt to repair the Seat Harness. Replace the Seat Harness if any of these conditions exist.
1. Replace the Passenger Seat Harness in accordance with the Service Information.
2. Perform the *OCCUPANT CLASSIFICATION MODULE SYSTEM VERIFICATION TEST .
3. Perform the *AIRBAG SYSTEM VERIFICATION TEST - VER 1 .
10) CHECKING STORED OR INTERMITTENT CODES
NOTE: Diagnose and repair all active codes before diagnosing stored codes. Refer to appropriate DIAGNOSTIC TEST .

With the scan tool, record and erase all Airbag System Module DTCs.

WARNING: To avoid personal injury or death, turn the ignition off, disconnect the battery and wait two minutes before proceeding.

Using the wiring diagram/schematic as a guide, inspect the related wiring and connectors for chafed, pierced, pinched, and partially broken wires, and for broken, bent, pushed out, corroded, and contaminated terminals. Repair as necessary.

Reconnect all disconnected components and harness connectors.

WARNING: To avoid personal injury or death, turn the ignition on, then reconnect the battery.

With the scan tool, monitor for active codes while performing the following:
- Wiggle the wiring harness and connectors of the related airbag circuit.
- Continue the test until either a code becomes active or the problem area is isolated.
In the previous steps you have attempted to recreate the conditions responsible for setting the DTC in question/causing the intermittent condition.

Are any ACTIVE DTCs present?

Yes
1. Select the appropriate diagnostic procedure, Refer to DIAGNOSTIC CODE INDEX .
No
1. No problem found at this time. Perform the Occupant Classification Module System Verification Test. Erase all codes before returning vehicle to customer.
2. Perform the *OCCUPANT CLASSIFICATION MODULE SYSTEM VERIFICATION TEST .