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Pinpoint Test T: DTC C1981




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

Pinpoint Tests

Pinpoint Test T: DTC C1981

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

Normal Operation

The seat track position sensor is comprised of integrated circuits called Hall-effect switch. The seat track position sensor indicate to the Restraints Control Module (RCM) the position of the driver seat, forward or rearward.

The RCM supplies current to the seat track position sensor. Current flows through the switch, both in the forward or rearward seat position to ground. The RCM will sense the difference in this current draw, 6 mA (forward) or 15 mA (rearward), and use this information in determining the deployment rate of the dual-stage driver air bag module. If the RCM detects current out of range, it will set a DTC.

If the RCM detects a short to battery on the driver seat track position sensor, it will store DTC C1981 in memory and send a message to the Instrument Cluster (IC) module to illuminate the air bag warning indicator.

- DTC C1981 Front Driver's Seat Track Position Switch Circuit Fault - If the RCM detects a short to voltage on the driver seat track position sensor circuit, it will set this DTC.

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



PINPOINT TEST T: DTC C1981

WARNING: Never probe the electrical connectors on safety belt buckle/retractor pretensioners or adaptive load limiting retractors. Failure to follow this instruction may result in the accidental deployment of the safety belt pretensioners or adaptive load limiting retractors, 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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T1 RETRIEVE RCM DTCs


- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was DTC C1981 retrieved on-demand during self-test?

Yes
This fault cannot be cleared until it is corrected and the DTC is no longer retrieved on-demand during self test. GO to T2.

No
This is an intermittent fault when present as a CMDTC only. GO to T5.

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T2 CHECK THE DRIVER SEAT TRACK POSITION SENSOR CIRCUIT FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Driver Seat Track Position Sensor C356.
- 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.
- Measure the voltage between driver seat track position sensor C356-2, circuit VR215 (OG), harness side and ground.




- Is any voltage present?

Yes
REPAIR circuit VR215 (OG). GO to T5.

No
GO to T3.

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T3 CONFIRM THE RCM FAULT


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

- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- 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 C2041a and C2041b connector position assurance 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 C2041a and C2041b.
- Connect: Driver Seat Track Position Sensor C356.
- 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.
- Was DTC C1981 retrieved on-demand during self-test?

Yes
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to T4.

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 T4.

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T4 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 the driver seat track position sensor C356:
- 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.
- repair any concerns found.

Refer to wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number

- Connect: All Previously Disconnected Component(s)/Connector(s).
- 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.
- Was DTC C1981 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 on-demand during self test. GO to T2.

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. REPAIR any intermittent wiring, terminal or connector concerns found.
GO to T5.

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T5 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 - Restraints.
- NOTE: When selecting Restraints from the Self Test menu, DTCs will be retrieved from the RCM and OCSM.
- Are any RCM and/or OCSM DTCs retrieved indicating a fault?

Yes
Do not clear any DTCs until all DTCs 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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