L20-L38

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

Pinpoint Tests

Pinpoint Test L: LFC 19/21 DTC B2293

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

Normal Operation

The Restraints Control Module (RCM) continuously monitors all front air bag module circuits (loop) for the following faults:

- Resistance out of range
- Unexpected voltage
- Short to ground

If a fault is detected, the RCM will store DTC B2293 in memory and send a message to the Instrument Cluster (IC) module to flash a Lamp Fault Code (LFC) 19 or 21 on the air bag warning indicator. After the LFCs are displayed, the air bag warning indicator will remain illuminated for the rest of the ignition cycle.

The RCM monitors all front air bag module circuits for resistance and expects a normal resistance for the driver air bag module loops between 1.84 and 3.96 ohms. The normal expected resistance for the passenger air bag module loops is between 1.50 and 3.04 ohms.

If a resistance for the driver air bag loops 1 or 2 is between 1.36 and 1.84 ohms or between 3.96 and 4.70 ohms, there exists a strong potential for a fault to occur (a DTC may or may not set). The RCM will also set a DTC if the loop resistance is less than 1.36 ohms or greater than 4.70 ohms.

If a loop resistance for the passenger air bag loops 1 and 2 is between 1.04 and 1.50 ohms or between 3.04 and 3.72 ohms, there exists a strong potential for a fault to occur (a DTC may or may not set). The RCM will also set a DTC if the loop resistance is less than 1.04 ohms or greater than 3.72 ohms.

a Fault PIDs that end in OD indicate an on-demand status and are associated with on-demand DTC B2293. Fault PIDs that end in CM indicate continuous memory status and are associated with continuous DTC B2293.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Clockspring
- Driver air bag module
- Passenger air bag module
- RCM

PINPOINT TEST L: LFC 19/21 DTC B2293

WARNING: Do not handle, move or change the original horizontal mounting position of the restraints control module (RCM) while the RCM is connected and the ignition switch is ON. Failure to follow this instruction may result in the accidental deployment of the Safety Canopy(R) and cause serious personal injury or death.

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 making 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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L20 CHECK THE DRIVER AIR BAG MODULE LOOP 2 FAULT PID FOR A FAULT STATUS CHANGE (OPEN INDICATED)

NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- 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.
- Connect a fused jumper wire between driver air bag module loop 2 electrical connector, pin-1, harness side and pin-2, harness side.
- 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 .
- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - View and Record the Following Fault PIDs .
- 2293_20_OD
- 2293_21_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module loop 2 circuits shorted together, a low resistance fault would normally be retrieved on loop 2. Loop 1 will show an open circuit fault due to the driver air bag being disconnected.
- Did the driver air bag module loop 2 on-demand fault PIDs change from an open circuit to a low resistance fault?

Yes
GO to L46.

No
GO to L21.

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L21 CHECK THE DRIVER AIR BAG MODULE LOOP 2 FAULT PID FOR A FAULT STATUS CHANGE (OPEN INDICATED) (CLOCKSPRING DISCONNECTED)

NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- Ignition OFF.
- Remove the fused jumper wire from driver air bag module loop 2 electrical connector.
- Disconnect: Clockspring C218.
- Connect a fused jumper wire between clockspring C218-2, circuit CR102 (BU), harness side and clockspring C218-10, circuit RR102 (WH), harness side.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM .
- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - View and Record the Following Fault PIDs .
- 2293_20_OD
- 2293_21_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module loop 2 circuits shorted together, a low resistance fault would normally be retrieved on loop 2. Loop 1 will show an open circuit fault due to the driver air bag being disconnected.
- Did the driver air bag module loop 2 on-demand fault PIDs change from an open circuit to a low resistance fault?

Yes
GO to L48.

No
GO to L22.

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L22 CHECK DRIVER AIR BAG MODULE LOOP 2 CIRCUITS FOR AN OPEN (CLOCKSPRING DISCONNECTED)

- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Remove the fused jumper wire from the clockspring connector.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM C310a, harness side and clockspring C218, harness side using the following chart.

- Are the resistances less than 0.5 ohm?

Yes
GO to L49.

No
REPAIR circuit CR102 (BU) or RR102 (WH). GO to L56.

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L23 CHECK THE DRIVER AIR BAG MODULE LOOP 2 FAULT PID FOR A FAULT STATUS CHANGE (SHORT TO GROUND INDICATED)

NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- 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.
- 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 .
- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - View and Record the Following Fault PIDs.
- 2293_21_OD
- 2293_23_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module disconnected, open circuit faults would normally be retrieved on loop 1 and loop 2.
- Did the driver air bag module loop 2 on-demand fault PID change from a short to ground to an open circuit fault?

Yes
GO to L46.

No
GO to L24.

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L24 CHECK THE DRIVER AIR BAG MODULE LOOP 2 FAULT PID FOR A FAULT STATUS CHANGE (SHORT TO GROUND INDICATED) (CLOCKSPRING DISCONNECTED)

NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- Ignition OFF.
- Disconnect: Clockspring C218.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM .
- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - View and Record the Following Fault PIDs.
- 2293_21_OD
- 2293_23_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module disconnected, open circuit faults would normally be retrieved on loop 1 and loop 2.
- Did the driver air bag module loop 2 on-demand fault PIDs change from a short to ground to an open circuit fault?

Yes
GO to L48.

No
GO to L25.

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L25 CHECK DRIVER AIR BAG MODULE LOOP 2 CIRCUITS 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: RCM C310a and C310b.
- Measure the resistance between clockspring:
- C218-2, circuit CR102 (BU), harness side and ground.
- C218-10, circuit RR102 (WH), harness side and ground.

- Are the resistances greater than 10,000 ohms?

Yes
GO to L49.

No
Due to the shorting bar feature in the RCM electrical connector, the fault can exist in either circuit. Do not remove or defeat the shorting bar.

REPAIR circuit CR102 (BU) or RR102 (WH). GO to L56.

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L26 CHECK THE DRIVER AIR BAG MODULE LOOP 2 FAULT PID FOR A FAULT STATUS CHANGE (SHORT TO BATTERY INDICATED) (CLOCKSPRING DISCONNECTED)

NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- 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: Clockspring C218.
- 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 .
- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - View and Record the Following Fault PIDs .
- 2293_21_OD
- 2293_22_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the driver air bag module/clockspring disconnected, open circuit faults would normally be retrieved on loop 1 and loop 2.
- Did the driver air bag module loop 2 on-demand fault PID change from a short to battery to an open circuit fault?

Yes
GO to L48.

No
GO to L27.

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L27 CHECK THE DRIVER AIR BAG MODULE LOOP 2 CIRCUITS 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: 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.
- Ignition ON.
- Measure the voltage between clockspring:
- C218-2, circuit CR102 (BU), harness side and ground.
- C218-10, circuit RR102 (WH), harness side and ground.

- Is voltage present on either circuit?

Yes
Due to the shorting bar feature in the RCM electrical connector, the fault can exist in either circuit. Do not remove or defeat the shorting bar.

REPAIR circuit CR102 (BU) or RR102 (WH). GO to L56.

No
GO to L49.

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L28 CHECK THE PASSENGER AIR BAG MODULE LOOP 1 (P_ABAGR) PID

- Enter the following diagnostic mode on the scan tool: DataLogger - RCM .
- Enter the following diagnostic mode on the scan tool: P_ABAGR PID .
- Does PID value read between 1.50 and 3.04 ohms?

Yes
GO to L49.

No
GO to L29.

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L29 CHECK THE PASSENGER AIR BAG MODULE LOOP 1 RESISTANCE (P_ABAGR) PID WHILE CARRYING OUT A HARNESS TEST

- While monitoring the P_ABAGR PID while carry out a harness test of the passenger air bag module circuits and accessible connectors (including any in-line connectors), by wiggling connectors and flexing the wire harness.
- Does the resistance PID value read between 1.50 and 3.04 ohms while carrying out the harness test?

Yes
DEPOWER the SRS and REPAIR the connector, terminals or wire harness as needed.

Refer to Wiring Diagram Set 5, Connector Repair Procedures for schematic and connector information. Diagrams By Number
GO to L56.

No
If the P_ABAGR PID is less than 1.50 ohms, GO to L30.

If the P_ABAGR PID is greater than 3.04 ohms, GO to L32.

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L30 CHECK THE PASSENGER AIR BAG MODULE LOOP 1 FAULT PID FOR A FAULT STATUS CHANGE (LOW RESISTANCE INDICATED)

NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- 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.
- 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 .
- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - View and Record the Following Fault PIDs.
- 2293_24_OD
- 2293_25_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the passenger air bag module disconnected, open circuit faults would normally be retrieved on loop 1 and loop 2.
- Did the passenger air bag module loop 1 on-demand fault PID change from a low resistance to an open circuit fault?

Yes
GO to L47.

No
GO to L31.

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L31 CHECK THE RCM FOR LOW RESISTANCE

- 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.
- Measure the resistance between RCM C310a pins 1 and 2, component side.

- Is the resistance greater than 10,000 ohms?

Yes
REPAIR circuits CR103 (GY/BU) and RR103 (VT/GN). GO to L56.

No
GO to L49.

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L32 CHECK THE PASSENGER AIR BAG MODULE LOOP 1 FAULT PID FOR A FAULT STATUS CHANGE (OPEN INDICATED)

NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- 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.
- Connect a fused jumper wire between passenger air bag module C256-1, circuit CR103 (GY/BU), harness side and C256-2, circuit RR103 (VT/GN), harness side.
- 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 .
- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - View and Record the Following Fault PIDs.
- 2293_24_OD
- 2293_25_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the passenger air bag module loop 1 circuits shorted together, a low resistance fault would normally be retrieved on loop 1. Loop 2 will show an open circuit fault due to the passenger air bag being disconnected.
- Did the passenger air bag module loop 1 on-demand fault PID change from an open circuit to a low resistance fault?

Yes
GO to L47.

No
GO to L33.

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L33 CHECK THE PASSENGER AIR BAG MODULE LOOP 1 CIRCUITS FOR AN OPEN

- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Remove the fused jumper wire from passenger air bag module C256.
- Disconnect: RCM C310a and C310b.
- Measure the resistance between RCM C310a, harness side and passenger air bag module C256, harness side using the following chart.

- Are the resistances less than 0.5 ohm?

Yes
GO to L49.

No
REPAIR circuit CR103 (GY/BU) or RR103 (VT/GN). GO to L56.

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L34 CHECK THE PASSENGER AIR BAG MODULE LOOP 1 FAULT PID FOR A FAULT STATUS CHANGE (SHORT TO GROUND INDICATED)

NOTE: This pinpoint test step will attempt to change the fault reported by the RCM by inducing a different fault condition. If the fault reported changes, this indicates the RCM is functioning correctly and is not the source of the fault.

- 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.
- 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 .
- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - View and Record the Following Fault PIDs.
- 2293_25_OD
- 2293_27_OD
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the passenger air bag module disconnected, open circuit faults would normally be retrieved on loop 1 and loop 2.
- Did the passenger air bag module loop 1 on-demand fault PID change from a short to ground to an open circuit fault?

Yes
GO to L47.

No
GO to L35.

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L35 CHECK THE PASSENGER AIR BAG MODULE LOOP 1 CIRCUITS 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: RCM C310a and C310b.
- Measure the resistance between passenger air bag module:
- C256-1, circuit CR103 (GY/BU), harness side and ground.
- C256-2, circuit RR103 (VT/GN), harness side and ground.