Pinpoint Test AB: DTC B2987
Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)
Pinpoint Test AB: DTC B2987
Refer to Wiring Diagram Set 46, Supplemental Restraint System for schematic and connector information. Diagrams By Number
Lamp Fault Codes (LFCs)
The following Lamp Fault Code (LFC) indicates the specific fault associated with DTC B2987:
- LFC 12-10 - Deployable Steering Column Circuit Resistance Low on Squib
Normal Operation
As part of the Supplemental Restraint System (SRS), the vehicle is equipped with a deployable steering column. The Restraints Control Module (RCM) will deploy (collapse) the steering column during a frontal collision when seat position information and other parameters reach predetermined limits. Refer to Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS) Description and Operation.
The RCM checks the deployable steering column circuits for faults. If the RCM detect low resistance on either circuit, it will store DTC B2987 in memory and flash LFC 12-10 on the air bag warning indicator.
- DTC B2987 (Deployable Steering Column Circuit Resistance Low on Squib) - If the RCM detects low resistance on the deployable steering column circuits, it will set this DTC.
This pinpoint test is intended to diagnose the following:
- Wiring, terminal or connectors
- Deployable steering column
- RCM
PINPOINT TEST AB: DTC B2987
WARNING: Remove restraint system diagnostic tools from the vehicle prior to road testing. If tools are not removed, the supplemental restraint system (SRS) device may not deploy in a crash. Failure to follow this instruction may result in serious personal injury or death in a crash and possibly violate vehicle safety standards.
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: The SRS must be fully operational and free of faults before releasing the vehicle to the customer.
NOTE: 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.
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AB1 CHECK FOR ON-DEMAND AND CONTINUOUS DTCs
- Enter the following diagnostic mode on the scan tool: Self-Test - RCM.
- Was DTC B2987 retrieved on-demand during self-test?
Yes
The fault condition is still present. This fault cannot be cleared until it is corrected and the DTC is no longer retrieved during the on-demand self-test. GO to AB2.
No
This is an intermittent fault when present as a Continuous Memory Diagnostic Trouble Code (CMDTC) only (DTC not retrieved on demand). The fault condition is not present at this time. GO to AB5.
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AB2 CHECK THE DEPLOYABLE STEERING COLUMN
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Deployable Steering Column C2318.
- Connect: Restraint System Diagnostic Service Tool 418-F395 to the Deployable Steering Column C2318.
- 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.
- Enter the following diagnostic mode on the scan tool: Self-Test - RCM.
- Was DTC B2987 retrieved on-demand during self-test?
Yes
GO to AB3.
No
INSTALL a new steering column. REFER to Steering Column Steering Column. GO to AB6.
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AB3 CHECK FOR A SHORT BETWEEN DEPLOYABLE STEERING COLUMN CIRCUITS 2136 (OG) AND 2137 (RD/BU)
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Restraint System Diagnostic Service Tool to the Deployable Steering Column C2318.
- Measure the resistance between deployable steering column C2318-1, circuit 2136 (OG), harness side and C2318-2, circuit 2137 (RD/BU), harness side.
- Is the resistance less than 800 ohms?
Yes
GO to AB4.
No
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to AB6.
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AB4 CHECK THE RCM FOR LOW RESISTANCE
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM C310a pin 21, component side and pin 22, component side.
- Is the resistance less than 800 ohms?
Yes
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to AB6.
No
REPAIR circuits 2136 (OG) and 2137 (RD/BU). GO to AB6.
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AB5 CHECK FOR AN INTERMITTENT FAULT
- Ignition OFF.
- Enter the following diagnostic mode on the scan tool: Self-Test - RCM.
- Was DTC B2987 retrieved on-demand during self-test?
Yes
The fault condition is now present. This fault cannot be cleared until it is corrected and the DTC is no longer retrieved during the on-demand self-test. GO to AB3.
No
CHECK for causes of the intermittent fault. ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. ACTIVATE other systems in the same wire harness. 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. REPAIR any intermittent wiring, terminal or connector concerns found. GO to AB6.
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AB6 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 - RCM.
- Are any RCM DTCs retrieved on-demand during self-test?
Yes
Do not clear any DTCs until all DTCs have been resolved. GO to the DTC Charts for pinpoint test direction. [1][2]Diagnostic Trouble Code Descriptions
No
CLEAR all RCM continuous memory DTCs. PROVE OUT the SRS. Repair is complete. RETURN the vehicle to the customer.
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