B1BBC-OCS NEGATIVE SYSTEM WEIGHT






OCS SEAT WEIGHTS MRL #9077



Possible Causes
DAMAGE TO THE PASSENGER SEAT STRUCTURE, RISER ASSEMBLY, CROSSMEMBERS, SEAT TRACKS, FLOOR PAN
OBJECT UNDER SEAT OR REAR SEAT FOLDED DOWN AND RESTING AGAINST PASSENGER SEAT
OCCUPANT CLASSIFICATION MODULE (OCM)




Diagnostic Test

1. CHECK FOR ACTIVE OCM DTCs

NOTE: Ensure 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 listed above?

Yes


No

2. ACTIVE OR STORED DTC

With the scan tool, read OCM DTCs.

Does the scan tool display active: B1BBC-OCS NEGATIVE SYSTEM WEIGHT?

Yes


No

3. PERFORM OCCUPANT CLASSIFICATION MODULE SYSTEM VERIFICATION TEST

Verify that the passenger seat is empty.

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, proceed as follows.
With the scan tool, read OCM DTCs.

Does the scan tool display active: B1BA8-OCS NOT CALIBRATED DTC?

Yes


No


No

4. VERIFY SEAT WEIGHT SENSOR TORQUE

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. Refer to Group 23 for 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, proceed as follows.
With the scan tool, read OCM DTCs.

Does the scan tool display active: B1BA8-OCS NOT CALIBRATED DTC?

Yes


No


No

5. STORED B1BBC-OCS NEGATIVE SYSTEM WEIGHT DTC

With the scan tool, record and erase all DTCs from all Airbag System Modules.
If any ACTIVE codes are present they must be resolved before diagnosing any stored codes.

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 wiring and connectors.
Look for chafed, pierced, pinched, or partially broken wires and broken, bent, pushed out, spread, corroded, or contaminated terminals.
The following additional checks may assist you in identifying a possible intermittent problem.
Reconnect any disconnected components and harness connector.

WARNING: To avoid serious or fatal injury, turn the ignition on, then reconnect the battery.


With the scan tool monitor active codes as you work through the following steps.
Wiggle the wiring harness and connectors of the related airbag circuit or component.
If only stored codes return continue the test until the problem area has been isolated.
In the previous steps you have attempted to recreate the conditions responsible for setting active DTC in question.

Are any ACTIVE DTC's present?

Yes


No