Pinpoint Test W: DTC B1993

Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)

Pinpoint Tests

Pinpoint Test W: DTC B1993

Refer to Wiring Diagram Set 46, Supplemental Restraint System for schematic and connector information. Diagrams By Number

Normal Operation

The Restraints Control Module (RCM) continuously monitors the driver seat side air bag circuits for the following faults:

- Resistance out of range
- Unexpected voltage
- Short to ground
- Faulted driver seat side air bag module

If a fault is detected, the RCM will store DTC B1993 in memory and send a message to the Instrument Cluster (IC) module to illuminate the air bag warning indicator.

- DTC B1993 (Driver Side, Side Mount Airbag Circuit Short to Ground) - When the RCM senses a short to ground on either driver seat side air bag circuit, a fault will be indicated.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Driver seat side air bag
- RCM


PINPOINT TEST W: DTC B1993

WARNING: Never probe the electrical connectors on air bag, Safety Canopy(R) or side air curtain modules. Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.

NOTICE: Use the correct probe adapter(s) from the Flex Probe Kit when taking measurements. Failure to use the correct probe adapter(s) may damage the connector.

Most faults are due to connector and/or wiring concerns. Carry out a thorough inspection and verification before proceeding with the pinpoint test. Inspection and Verification

NOTE: Supplemental Restraint System (SRS) components should only be disconnected or reconnected when instructed to do so within a pinpoint test step. Failure to follow this instruction may result in incorrect diagnosis of the SRS.

NOTE: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.

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W1 RETRIEVE RCM DTCs


NOTE: All RCM diagnosis will be carried out using Continuous Memory Diagnostic Trouble Codes (CMDTCs) and status information. Refer to DTC Fault Reporting and Status Information. DTC Fault Reporting and Status Information

- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Select the DTC and view DTC Status information.
- Does the status information for DTC B1993 indicate a fault was present at the time of request?

Yes
This fault cannot be cleared until it is corrected and the DTC Status information indicates the fault is no longer present. GO to W2.

No
This is an intermittent fault. The DTC Status information indicates the fault was not present at time of request. GO to W5.

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W2 CHECK THE DRIVER SEAT SIDE AIR BAG FOR A FAULT STATUS CHANGE


NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Driver Seat Bulkhead Connector.
- Repower the SRS. Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Select the DTC and view DTC Status information.
- DIAGNOSTIC TIP: When viewing DTCs with the driver seat side air bag disconnected, an open circuit fault would normally be retrieved.
- Does the status information for DTC B1993 indicate a fault was present at the time of request?

Yes
GO to W3.

No
REMOVE the seat side air bag module jumper harness and INSPECT the harness and connector terminals for damage. REFER to Side Air Bag Module Side Air Bag Module. If a concern is found, REPAIR as necessary.

If a concern is not found, INSTALL a new driver seat side air bag module. REFER to Side Air Bag Module Side Air Bag Module. GO to W6.

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W3 CHECK THE DRIVER SEAT SIDE AIR BAG CIRCUITS FOR A SHORT TO GROUND


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: RCM C310A and C310B.
- Measure the resistance between the driver seat side air bag:
- C339A-2, circuit 15S-JA37 (GN/BK), harness side and ground.
- C339A-1, circuit 91S-JA37 (BK/GN), harness side and ground.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W4.

No
REPAIR circuit 15S-JA37 (GN/BK) or 91S-JA37 (BK/GN). GO to W6.

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W4 CONFIRM THE RCM FAULT


NOTE: Make sure all restraint system components and the RCM electrical connectors are connected before carrying out the self-test. If not, DTCs will be recorded.

- Prior to reconnecting any previously disconnected SRS component:
- inspect connector(s) (including any in-line connectors) for pushed-out, loose or spread terminals and loose or frayed wire connections at terminals.
- inspect wire harness for any damage, pinched, cut or pierced wires.
- inspect RCM C310A and C310B Connector Position Assurance (CPA) lever/lock for correct operation. Refer to Restraints Control Module (RCM) Service and Repair.
- repair any concerns found.
Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number

- Connect: RCM C310A and C310B .
- Connect: Driver Seat Bulkhead Connector.
- Repower the SRS. Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Select the DTC and view DTC Status information.
- Does the status information for the DTC B1993 indicate a fault was present at the time of request?

Yes
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to W6.

No
In the process of diagnosing the fault, the fault condition has become intermittent. Do not install any new SRS components at this time. SRS components should only be installed when directed to do so in the pinpoint test. GO to W5.

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W5 CHECK FOR AN INTERMITTENT DRIVER SEAT SIDE AIR BAG SHORT TO GROUND FAULT


- Attempt to recreate the fault by wiggling connectors (including any in-line connectors) and flexing the wire harness.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Select the DTC and view DTC Status information.
- Does the status information for DTC B1993 indicate a fault was present at the time of request?

Yes
DEPOWER the SRS and REPAIR as necessary.
Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number
GO to W6.

No
The fault is not present and cannot be recreated at this time. Do not install any new SRS components at this time. SRS components should only be installed when directed to do so in the pinpoint test. GO to W6.

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W6 CHECK FOR ADDITIONAL SRS DTCs


- Ignition OFF.

- WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.

- Reconnect all SRS components (if previously disconnected).
- If previously directed to depower the SRS, repower the SRS. Do not prove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - Restraints.

- NOTE: When selecting Restraints from the Self Test menu, DTCs will be retrieved from the RCM and OCSM.

- Select the DTC and view DTC Status information.
- Does the status information for any RCM DTC indicate a fault is present and/or are any OCSM on-demand DTCs retrieved?

Yes
Do not clear any DTCs until all DTC concerns have been resolved. GO to the DTC Charts for pinpoint test direction. Diagnostic Trouble Code Tests and Associated Procedures

No
CLEAR all RCM and OCSM CMDTCs. PROVE OUT the SRS. Repair is complete. RETURN the vehicle to the customer.

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