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Pinpoint Tests AA: DTC B2986




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


Pinpoint Tests


Pinpoint Test AA: DTC B2986

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 B2986:

- LFC 12-9 - Deployable Steering Column Circuit Short to Ground

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 detects a short to ground on either circuit, it will store DTC B2986 in memory and flash LFC 12-9 on the air bag warning indicator.

- DTC B2986 Deployable Steering Column Circuit Short to Ground - If the RCM detects a short to ground on the deployable steering column circuits, it will set this DTC.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Deployable steering column
- RCM



PINPOINT TEST AA: DTC B2986

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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AA1 CHECK FOR ON-DEMAND AND CONTINUOUS DTCs


- Enter the following diagnostic mode on the scan tool: Self-Test - RCM.
- Was DTC B2986 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 AA2.

No
This is an intermittent fault when present as a continuous memory DTC only (DTC not retrieved on demand). The fault condition is not present at this time. GO to AA5.

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AA2 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 B2986 retrieved on-demand during self-test?

Yes
GO to AA3.

No
REPAIR circuit 2136 (OG) or 2137 (RD/BU). GO to AA6.

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AA3 CHECK CIRCUITS 2136 (OG) AND 2137 (RD/BU) 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: Deployable Steering Column Restraints System Diagnostic Tool.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between deployable steering column:
- C2318-1, circuit 2136 (OG), harness side and ground.
- C2318-2, circuit 2137 (RD/BU), harness side and ground.




- Are the resistances greater than 10,000 ohms?

Yes
GO to AA4.

No
REPAIR circuit 2136 (OG) or 2137 (RD/BU). GO to AA6.

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AA4 CONFIRM THE RCM FAULT


NOTE: Make sure all Restraint System Diagnostic Service Tools, sensor electrical connectors and the RCM electrical connectors are connected before carrying out the self-test. If not, erroneous DTCs will be recorded.

- Ignition OFF.
- Connect: Restraint System Diagnostic Service Tool 418-F395 to Deployable Steering Column C2318.
- Connect: RCM C310a and C310b.
- 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 B2986 retrieved on-demand during self-test?

Yes
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to AA6.

No
In the process of diagnosing the fault, the fault condition has become intermittent. CHECK for causes of the intermittent fault in the areas previously worked in, particularly the pins and terminals of electrical connectors that were disconnected. ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition key frequently. 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 AA6.

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AA5 CHECK FOR AN INTERMITTENT FAULT


- 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.
- Enter the following diagnostic mode on the scan tool: Self-Test - RCM.
- Was DTC B2986 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 AA3.

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 AA6.

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AA6 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 notprove 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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