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Home >> Lincoln >> 2011 >> Town Car V8-4.6L >> Repair and Diagnosis >> Restraints and Safety Systems >> Air Bag Systems >> Testing and Inspection >> Pinpoint Tests >> Pinpoint Test W: DTC B2792 >> Pinpoint Test W14-W26

Pinpoint Test W14-W26




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

Pinpoint Test W: DTC B2792

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 B2792:

- LFC 12-11 - Cross Link Between Firing Loops

Normal Operation

The Restraints Control Module (RCM) monitors all deployable devices for a cross link fault between circuits. If the RCM detects a short between any of the deployable circuits, it will store a DTC B2792 in memory, flash LFC 12-11 on the air bag warning indicator.





a Fault PIDs that end in OD indicate an on-demand status and are associated with on-demand DTC B2792. Fault PIDs that end in CM indicate continuous memory status and are associated with continuous DTC B2792.

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


PINPOINT TEST W: B2792

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.

WARNING: Never disassemble or tamper with safety belt buckle/retractor pretensioners or adaptive load limiting retractors or probe the electrical connectors. 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: The Supplemental Restraint System (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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W14 CHECK FOR A SHORT BETWEEN DRIVER AIR BAG MODULE LOOP 2 CIRCUITS AND DRIVER SEAT SIDE AIR BAG MODULE CIRCUITS


- Ignition OFF.
- Depower the SRS. 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 Driver Air Bag Module.
- Disconnect: Driver Seat Side Air Bag Module C315.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM:
- C310a-5, circuit 1516 (YE/WH), harness side and RCM C310b-1, circuit 1257 (WH/LB), harness side.
- C310a-5, circuit 1516 (YE/WH), harness side and RCM C310b-2, circuit 1258 (RD), harness side.
- C310a-6, circuit 1517 (RD/OG), harness side and RCM C310b-1, circuit 1257 (WH/LB), harness side.
- C310a-6, circuit 1517 (RD/OG), harness side and RCM C310b-2, circuit 1258 (RD), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W38.

No
REPAIR the affected circuits. GO to W40.

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W15 CHECK FOR A SHORT BETWEEN DRIVER AIR BAG MODULE LOOP 2 CIRCUITS AND PASSENGER SEAT SIDE AIR BAG MODULE CIRCUITS


- Ignition OFF.
- Depower the SRS. 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 Driver Air Bag Module.
- Disconnect: Passenger Seat Side Air Bag Module C316.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM:
- C310a-5, circuit 1516 (YE/WH), harness side and RCM C310b-21, circuit 1259 (WH/YE), harness side.
- C310a-5, circuit 1516 (YE/WH), harness side and RCM C310b-22, circuit 1260 (BN/YE), harness side.
- C310a-6, circuit 1517 (RD/OG), harness side and RCM C310b-21, circuit 1259 (WH/YE), harness side.
- C310a-6, circuit 1517 (RD/OG), harness side and RCM C310b-22, circuit 1260 (BN/YE), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W38.

No
REPAIR the affected circuits. GO to W40.

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W16 CHECK FOR A SHORT BETWEEN DRIVER AIR BAG MODULE LOOP 2 CIRCUITS AND DEPLOYABLE STEERING COLUMN CIRCUITS


- Ignition OFF.
- Depower the SRS. 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 Driver Air Bag Module.
- Disconnect: Deployable Steering Column C2318.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM:
- C310a-5, circuit 1516 (YE/WH, harness side and RCM C310a-21, circuit 2136 (OG), harness side.
- C310a-5, circuit 1516 (YE/WH), harness side and RCM C310a-22, circuit 2137 (RD/BU), harness side.
- C310a-6, circuit 1517 (RD/OG), harness side and RCM C310a-21, circuit 2136 (OG), harness side.
- C310a-6, circuit 1517 (RD/OG), harness side and RCM C310a-22, circuit 2137 (RD/BU), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W38.

No
REPAIR the affected circuits. GO to W40.

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W17 CHECK FOR A SHORT BETWEEN PASSENGER AIR BAG MODULE LOOP 1 CIRCUITS AND PASSENGER AIR BAG MODULE LOOP 2 CIRCUITS


- 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.
- Disconnect: Passenger Air Bag Module C256.
- Measure the resistance between RCM:
- C310a-3, circuit 607 (LB/OG), harness side and RCM C310a-13, circuit 1518 (BK/WH), harness side.
- C310a-3, circuit 607 (LB/OG), harness side and RCM C310a-14, circuit 1519 (LG/RD), harness side.
- C310a-4, circuit 616 (PK/BK), harness side and RCM C310a-13, circuit 1518 (BK/WH), harness side.
- C310a-4, circuit 616 (PK/BK), harness side and RCM C310a-14, circuit 1519 (LG/RD), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W38.

No
REPAIR the affected circuits. GO to W40.

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W18 CHECK FOR A SHORT BETWEEN PASSENGER AIR BAG MODULE LOOP 1 CIRCUITS AND DRIVER SAFETY BELT PRETENSIONER CIRCUITS


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Air Bag Module C256.
- Disconnect: Driver Safety Belt Retractor Pretensioner C323.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM:
- C310a-3, circuit 607 (LB/OG), harness side and RCM C310b-17, circuit 1079 (LG/RD), harness side.
- C310a-3, circuit 607 (LB/OG), harness side and RCM C310b-18, circuit 1080 (LG/BK), harness side.
- C310a-4, circuit 616 (PK/BK), harness side and RCM C310b-17, circuit 1079 (LG/RD), harness side.
- C310a-4, circuit 616 (PK/BK), harness side and RCM C310b-18, circuit 1080 (LG/BK), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W38.

No
REPAIR the affected circuits. GO to W40.

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W19 CHECK FOR A SHORT BETWEEN PASSENGER AIR BAG MODULE LOOP 1 CIRCUITS AND PASSENGER SAFETY BELT PRETENSIONER CIRCUITS


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Air Bag Module C256.
- Disconnect: Passenger Safety Belt Retractor Pretensioner C303.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM:
- C310a-3, circuit 607 (LB/OG), harness side and RCM C310b-35, circuit 1081 (YE/RD), harness side.
- C310a-3, circuit 607 (LB/OG), harness side and RCM C310b-36, circuit 1082 (LB/BK), harness side.
- C310a-4, circuit 616 (PK/BK), harness side and RCM C310b-35, circuit 1081 (YE/RD), harness side.
- C310a-4, circuit 616 (PK/BK), harness side and RCM C310b-36, circuit 1082 (LB/BK), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W38.

No
REPAIR the affected circuits. GO to W40.

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W20 CHECK FOR A SHORT BETWEEN PASSENGER AIR BAG MODULE LOOP 1 CIRCUITS AND DRIVER SEAT SIDE AIR BAG MODULE CIRCUITS


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Air Bag Module C256.
- Disconnect: Driver Seat Side Air Bag Module C315.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM:
- C310a-3, circuit 607 (LB/OG), harness side and RCM C310b-1, circuit 1257 (WH/LB), harness side.
- C310a-3, circuit 607 (LB/OG), harness side and RCM C310b-2, circuit 1258 (RD), harness side.
- C310a-4, circuit 616 (PK/BK), harness side and RCM C310b-1, circuit 1257 (WH/LB), harness side.
- C310a-4, circuit 616 (PK/BK), harness side and RCM C310b-2, circuit 1258 (RD), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W38.

No
REPAIR the affected circuits. GO to W40.

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W21 CHECK FOR A SHORT BETWEEN PASSENGER AIR BAG MODULE LOOP 1 CIRCUITS AND PASSENGER SEAT SIDE AIR BAG MODULE CIRCUITS


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Air Bag Module C256.
- Disconnect: Passenger Seat Side Air Bag Module C316.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM:
- C310a-3, circuit 607 (LB/OG), harness side and RCM C310b-21, circuit 1259 (WH/YE), harness side.
- C310a-3, circuit 607 (LB/OG), harness side and RCM C310b-22, circuit 1260 (BN/YE), harness side.
- C310a-4, circuit 616 (PK/BK), harness side and RCM C310b-21, circuit 1259 (WH/YE), harness side.
- C310a-4, circuit 616 (PK/BK), harness side and RCM C310b-22, circuit 1260 (BN/YE), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W38.

No
REPAIR the affected circuits. GO to W40.

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W22 CHECK FOR A SHORT BETWEEN PASSENGER AIR BAG MODULE LOOP 1 CIRCUITS AND DEPLOYABLE STEERING COLUMN CIRCUITS


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Air Bag Module C256.
- Disconnect: Deployable Steering Column C2318.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM:
- C310a-3, circuit 607 (LB/OG), harness side and RCM C310a-21, circuit 2136 (OG), harness side.
- C310a-3, circuit 607 (LB/OG), harness side and RCM C310a-22, circuit 2137 (RD/BU), harness side.
- C310a-4, circuit 616 (PK/BK), harness side and RCM C310a-21, circuit 2136 (OG), harness side.
- C310a-4, circuit 616 (PK/BK), harness side and RCM C310a-22, circuit 2137 (RD/BU), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W38.

No
REPAIR the affected circuits. GO to W40.

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W23 CHECK FOR A SHORT BETWEEN PASSENGER AIR BAG MODULE LOOP 2 CIRCUITS AND DRIVER SAFETY BELT PRETENSIONER CIRCUITS


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Air Bag Module C256.
- Disconnect: Driver Safety Belt Retractor Pretensioner C323.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM:
- C310a-13, circuit 1518 (BK/WH), harness side and RCM C310b-17, circuit 1079 (LG/RD), harness side.
- C310a-13, circuit 1518 (BK/WH), harness side and RCM C310b-18, circuit 1080 (LG/BK), harness side.
- C310a-14, circuit 1519 (LG/RD), harness side and RCM C310b-17, circuit 1079 (LG/RD), harness side.
- C310a-14, circuit 1519 (LG/RD), harness side and RCM C310b-18, circuit 1080 (LG/BK), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W38.

No
REPAIR the affected circuits. GO to W40.

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W24 CHECK FOR A SHORT BETWEEN PASSENGER AIR BAG MODULE LOOP 2 CIRCUITS AND PASSENGER SAFETY BELT PRETENSIONER CIRCUITS


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Air Bag Module C256.
- Disconnect: Passenger Safety Belt Retractor Pretensioner C303.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM:
- C310a-13, circuit 1518 (BK/WH), harness side and RCM C310b-35, circuit 1081 (YE/RD), harness side.
- C310a-13, circuit 1518 (BK/WH), harness side and RCM C310b-36, circuit 1082 (LB/BK), harness side.
- C310a-14, circuit 1519 (LG/RD), harness side and RCM C310b-35, circuit 1081 (YE/RD), harness side.
- C310a-14, circuit 1519 (LG/RD), harness side and RCM C310b-36, circuit 1082 (LB/BK), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W38.

No
REPAIR the affected circuits. GO to W40.

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W25 CHECK FOR A SHORT BETWEEN PASSENGER AIR BAG MODULE LOOP 2 CIRCUITS AND DRIVER SEAT SIDE AIR BAG MODULE CIRCUITS


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Air Bag Module C256.
- Disconnect: Driver Seat Side Air Bag Module C315.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM:
- C310a-13, circuit 1518 (BK/WH), harness side and RCM C310b-1, circuit 1257 (WH/LB), harness side.
- C310a-13, circuit 1518 (BK/WH), harness side and RCM C310b-2, circuit 1258 (RD), harness side.
- C310a-14, circuit 1519 (LG/RD), harness side and RCM C310b-1, circuit 1257 (WH/LB), harness side.
- C310a-14, circuit 1519 (LG/RD), harness side and RCM C310b-2, circuit 1258 (RD), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W38.

No
REPAIR the affected circuits. GO to W40.

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W26 CHECK FOR A SHORT BETWEEN PASSENGER AIR BAG MODULE LOOP 2 CIRCUITS AND PASSENGER SEAT SIDE AIR BAG MODULE CIRCUITS


- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: Passenger Air Bag Module C256.
- Disconnect: Passenger Seat Side Air Bag Module C316.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM:
- C310a-13, circuit 1518 (BK/WH), harness side and RCM C310b-21, circuit 1259 (WH/YE), harness side.
- C310a-13, circuit 1518 (BK/WH), harness side and RCM C310b-22, circuit 1260 (BN/YE), harness side.
- C310a-14, circuit 1519 (LG/RD), harness side and RCM C310b-21, circuit 1259 (WH/YE), harness side.
- C310a-14, circuit 1519 (LG/RD), harness side and RCM C310b-22, circuit 1260 (BN/YE), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to W38.

No
REPAIR the affected circuits. GO to W40.

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