B1936
Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)
Pinpoint Test T: DTC B1936
Refer to Wiring Diagrams Set 46, Supplemental Restraint System for schematic and connector information. Electrical Diagrams
Normal Operation
The Restraints Control Module (RCM) continuously monitors the driver air bag module stage 1 and circuits for the following faults:
- Resistance out of range
- Unexpected voltage
- Short to ground
- Faulted driver air bag module
If a fault is detected, the RCM (Restraints Control Module) will store DTC B1936 in memory and send a message to the Instrument Cluster (IC) module to illuminate the air bag warning indicator.
- DTC B1936 (Air Bag Driver Circuit Short to Ground)- When the RCM (Restraints Control Module) senses a short to ground on either driver air bag stage 1 circuit, a fault will be indicated.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Driver air bag module
- Clockspring
- RCM (Restraints Control Module)
PINPOINT TEST T : DTC B1936
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 (Supplemental Restraint System).
NOTE: The SRS (Supplemental Restraint System) must be fully operational and free of faults before releasing the vehicle to the customer.
T1 RETRIEVE RCM (Restraints Control Module) DTCs
NOTE: All RCM (Restraints Control Module) 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 (Restraints Control Module).
- Select the DTC and view DTC Status information.
Does the status information for DTC B1936 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 T2.
No
This is an intermittent fault. The DTC Status information indicates the fault was not present at time of request. GO to T8.
T2 CHECK THE DRIVER AIR BAG STAGE 1 FOR A FAULT STATUS CHANGE
NOTE: This pinpoint test step will attempt to change the fault reported by the RCM (Restraints Control Module) by inducing a different fault condition. If the fault reported changes, this indicates the RCM (Restraints Control Module) is functioning correctly and is not the source of the fault.
- Ignition OFF.
- Depower the SRS (Supplemental Restraint System). Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Remove the driver air bag module. Refer to Driver Air Bag Module .
- Repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) 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 (Restraints Control Module).
- Select the DTC and view DTC Status information.
- DIAGNOSTIC TIP: When viewing DTCs with the driver air bag module disconnected, open circuit faults would normally be retrieved on stage 1 and 2.
Does the status information for DTC B1936 indicate a fault was present at the time of request?
Yes
GO to T3.
No
GO to T5.
T3 CHECK THE DRIVER AIR BAG STAGE 1 FOR A FAULT STATUS CHANGE (CLOCKSPRING DISCONNECTED)
NOTE: This pinpoint test step will attempt to change the fault reported by the RCM (Restraints Control Module) by inducing a different fault condition. If the fault reported changes, this indicates the RCM (Restraints Control Module) is functioning correctly and is not the source of the fault.
- 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.
- Disconnect: Clockspring C218.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test- RCM (Restraints Control Module).
- Select the DTC and view DTC Status information.
- DIAGNOSTIC TIP: When viewing DTCs with the driver air bag module/clockspring disconnected, open circuit faults would normally be retrieved on stage 1 and 2.
Does the status information for DTC B1936 indicate a fault was present at the time of request?
Yes
GO to T4.
No
GO to T6.
T4 CHECK THE DRIVER AIR BAG STAGE 1 CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Depower the system. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: RCM (Restraints Control Module) C310A and C310B.
- Measure the resistance between clockspring:
- C218-1, circuit 15S-JA8 (GN/RD), harness side and ground.
- C218-2, circuit 91S-JA8 (BK/OG), harness side and ground.
Are the resistances greater than 10,000?
Yes
GO to T7.
No
REPAIR circuit 15S-JA8 (GN/RD) or 91S-JA8 (BK/OG). GO to T9.
T5 CONFIRM THE DRIVER AIR BAG MODULE FAULT
NOTE: Make sure all restraint system components and the RCM (Restraints Control Module) electrical connectors are connected before carrying out the self-test. If not, DTCs will be recorded.
- Ignition OFF.
- Depower the SRS (Supplemental Restraint System). Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Install the driver air bag module. Refer to Driver Air Bag Module .
- Repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) 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 (Restraints Control Module).
- Select the DTC and view DTC Status information.
Does the status information for DTC B1936 indicate a fault was present at the time of request?
Yes
INSTALL a new driver air bag module. REFER to Driver Air Bag Module . GO to T10.
No
In the process of diagnosing the fault, the fault condition has become intermittent. Do not install any new SRS (Supplemental Restraint System) components at this time. SRS (Supplemental Restraint System) components should only be installed when directed to do so in the pinpoint test.
GO to T8.
T6 CONFIRM THE CLOCKSPRING FAULT
NOTE: Make sure all restraint system components and the RCM (Restraints Control Module) electrical connectors are connected before carrying out the self-test. If not, DTCs will be recorded.
- Ignition OFF.
- Depower the SRS (Supplemental Restraint System). Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Connect: Clockspring C218.
- Install the driver air bag module. Refer to Driver Air Bag Module .
- Repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) 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 (Restraints Control Module).
- Select the DTC and view DTC Status information.
Does the status information for DTC B1936 indicate a fault was present at the time of request?
Yes
INSTALL a new clockspring. REFER to Clockspring . GO to T10.
No
In the process of diagnosing the fault, the fault condition has become intermittent. Do not install any new SRS (Supplemental Restraint System) components at this time. SRS (Supplemental Restraint System) components should only be installed when directed to do so in the pinpoint test.
GO to T8.
T7 CONFIRM THE RCM (Restraints Control Module) FAULT
NOTE: Make sure all restraint system components and the RCM (Restraints Control Module) electrical connectors are connected before carrying out the self-test. If not, DTCs will be recorded.
- Ignition OFF.
- Depower the SRS (Supplemental Restraint System). Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Prior to reconnecting any previously disconnected SRS (Supplemental Restraint System) 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 (Restraints Control Module) C310A and C310B Connector Position Assurance (CPA) lever/lock for correct operation. Refer to Restraints Control Module (RCM) .
- repair any concerns found.
Refer to Wiring Diagrams Set 5, Connector Repair Procedures for schematic and connector information. Electrical Diagrams
- Install the driver air bag module. Refer to Driver Air Bag Module .
- Connect: Clockspring C218 (if previously disconnected).
- Connect: RCM (Restraints Control Module) C310A and C310B (if previously disconnected).
- Repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) 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 (Restraints Control Module).
- Select the DTC and view DTC Status information.
Does the status information for DTC B1936 indicate a fault was present at the time of request?
Yes
INSTALL a new RCM (Restraints Control Module). REFER to Restraints Control Module (RCM) . GO to T10.
No
In the process of diagnosing the fault, the fault condition has become intermittent. Do not install any new SRS (Supplemental Restraint System) components at this time. SRS (Supplemental Restraint System) components should only be installed when directed to do so in the pinpoint test. GO to T8.
T8 CHECK FOR AN INTERMITTENT FAULT
- Ignition OFF.
- Depower the SRS (Supplemental Restraint System). Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Remove the driver air bag module. Refer to Driver Air Bag Module .
- Disconnect: Clockspring C218.
- Disconnect: RCM (Restraints Control Module) C310A and C310B.
- Inspect for the following:
- inspect harness and component connectors for 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 (Restraints Control Module) C310A and C310B CPA (Connector Position Assurance) lever/lock for correct operation. Refer to Restraints Control Module (RCM) .
- repair any concerns found.
Refer to Wiring Diagrams Set 5, Connector Repair Procedures for schematic and connector information. Electrical Diagrams
- Connect: All Previously Disconnected Component(s)/Connector(s).
- Repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) 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 (Restraints Control Module).
- Select the DTC and view DTC Status information.
Does the status information for DTC B1936 indicate a fault was present at the time of request?
Yes
The fault condition is now present. Do not clear any DTCs until all DTC concerns have been resolved.
GO to T2.
No
The fault is not present and cannot be recreated at this time. Do not install any new SRS (Supplemental Restraint System) components at this time. SRS (Supplemental Restraint System) components should only be installed when directed to do so in the pinpoint test. GO to T9.
T9 CHECK THE HARNESS AND CONNECTORS
- Ignition OFF.
- Depower the SRS (Supplemental Restraint System). Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- If previously installed, remove the driver air bag module:
- inspect connector(s) (including any in-line connectors) for corrosion, 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 (Restraints Control Module) C310A and C310B CPA (Connector Position Assurance) lever/lock for correct operation. Refer to Restraints Control Module (RCM) .
Were any concerns found?
Yes
REPAIR as necessary.
Refer to Wiring Diagrams Set 5, Connector Repair Procedures for schematic and connector information. GO to T10. Electrical Diagrams
No
The fault is not present and cannot be recreated at this time. Do not install any new SRS (Supplemental Restraint System) components at this time. SRS (Supplemental Restraint System) components should only be installed when directed to do so in the pinpoint test. GO to T10.
T10 CHECK FOR ADDITIONAL SRS (Supplemental Restraint System) 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 (Supplemental Restraint System) components (if previously disconnected).
- If previously directed to depower the SRS (Supplemental Restraint System), repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) 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 (Restraints Control Module) and OCSM (Occupant Classification System Module).
- Select the DTC and view DTC Status information.
Does the status information for any RCM (Restraints Control Module) DTC indicate a fault is present and/or are any OCSM (Occupant Classification System Module) 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. Air Bag Systems / Seat Belt Systems
No
CLEAR all RCM (Restraints Control Module) and OCSM (Occupant Classification System Module) CMDTCs (Continuous Memory Diagnostic Trouble Codes). PROVE OUT the SRS (Supplemental Restraint System). Repair is complete. RETURN the vehicle to the customer.