B1B78
B1B78-PASSENGER SEAT WEIGHT SENSOR 3 - LEFT FRONT PERFORMANCE
For a complete wiring diagram refer to Diagrams/Electrical.
- When Monitored:
When CAN ignitions status is Run or Signal Not Available (SNA), during auto zero and while performing the Occupant Classification Module System Verification Test.
- Set Condition:
During the Occupant Classification Module system verification test: if the module detects that the sensor input is less than 1.4 volts or greater than 3.6 volts. During auto zero: if the module detects that the sensor input is less than 1 volt or greater than 4 volts.
Diagnostic Test
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
- Diagnose and repair the DTCs.
No
- Go To 2
2. VERIFY THAT DTC B1B78-PASSENGER SEAT WEIGHT SENSOR 3 - LEFT FRONT PERFORMANCE IS ACTIVE
With the scan tool, read OCM DTCs.
Does the scan tool display active: B1B78-PASSENGER SEAT WEIGHT SENSOR 3 - LEFT FRONT PERFORMANCE?
Yes
- Go To 3
No
- Go To 6
3. INSPECT PASSENGER SEAT HARNESS WIRES AND CONNECTORS
WARNING: To avoid serious or fatal injury, 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.
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.
- Perform *OCM SYSTEM VERIFICATION TEST. Occupant Classification Module (OCM) System Verification Test
No
- Go To 4
Diagnostic Test
4. PERFORM THE OCM VERIFICATION TEST
NOTE: Ensure that the battery is fully charged.
NOTE: The Occupant Classification Seat Weights 9077 are required to perform this test.
Remove any special tools or jumper wires and reconnect all previously disconnected components - except the battery.
WARNING: To avoid serious or fatal injury, turn the ignition on, then reconnect the battery.
NOTE: Failure to follow the test instructions or aborting the test will cause 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 OCM DTCs.
Does the scan tool display any active PASSENGER SEAT WEIGHT SENSOR DTCs?
Yes
- Go To 5
No
- Perform *AIRBAG SYSTEM VERIFICATION TEST - VER 1. Airbag System Verification Test
5. PERFORM SEAT WEIGHT SENSOR VERIFICATION TEST
WARNING: To avoid serious or fatal injury, turn the ignition off, disconnect the battery and wait two minutes before proceeding.
Verify that all of the Seat Weight Sensor mounting screws are tightened to torque specification.
WARNING: To avoid serious or fatal injury, turn the ignition on, then reconnect the battery.
NOTE: Failure to follow the test instructions or aborting the test will cause 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 OCM DTCs.
Does the scan tool display any active PASSENGER SEAT WEIGHT SENSOR PERFORMANCE?
Yes
- Perform the *Diagnosis/Checkout Procedure For Seat Weight Sensors. Component Tests and General Diagnostics
No - But Other DTCs Present
- Diagnose and repair the DTCs.
No Active DTCs Present
- Perform *AIRBAG SYSTEM VERIFICATION TEST - VER 1. Airbag System Verification Test
6. CHECKING STORED OR INTERMITTENT CODES
NOTE: Diagnose and repair all active codes before diagnosing stored codes.
With the scan tool, record and erase all Airbag System Module DTCs.
WARNING: To avoid serious or fatal injury, 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 serious or fatal injury, 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
- Select the appropriate diagnostic procedure.
No
- No problem found at this time. Perform the Occupant Classification Module System Verification Test. Erase all codes before returning vehicle to customer. Occupant Classification Module (OCM) System Verification Test