Part 4

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

Pinpoint Tests

Pinpoint Test H: 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 an acceptable resistance range, unacceptable voltage and shorts to ground. The RCM will set on-demand and store DTC B2293 in memory if any of these conditions are detected. If the RCM detects a fault on any of the front air bag circuits, it will store DTC B2293 in memory and send a message to the Instrument Cluster (IC) module to illuminate the air bag warning indicator.

As the RCM continuously monitors all front air bag module circuits for resistance, it expects a normal loop resistance between 1.31 to 4.29 ohms.

If any loop (loop 1, loop 2, canister vent and/or adaptive tether) resistance for the driver and/or passenger air bag is between 0.9 and 1.31 or between 4.29 and 5 ohms, there exists a strong potential for an intermittent fault, a DTC may or may not set. The RCM will also set an on-demand DTC if the loop resistance is less than 0.9 ohm or greater than 5 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
- Air bag module
- RCM

PINPOINT TEST H: 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: Always tighten the fasteners of the restraints control module (RCM) and impact sensor (if equipped) to the specified torque. Failure to do so may result in incorrect restraint system operation, which increases the risk of personal injury or death in a crash.

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 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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H46 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 jumper wire from passenger air bag module C256.
- Disconnect: RCM C310a and C310b.
- Measure resistance between RCM C310a-1, circuit CR103 (GY/BU), harness side and passenger air bag module C256-3, circuit CR103 (GY/BU), harness side.

- Measure resistance between RCM C310a-2, circuit RR103 (VT/GN), harness side and passenger air bag module C256-4, circuit RR103 (VT/GN), harness side.

- Are resistances less than 0.5 ohm?

Yes
GO to H80.

No
REPAIR circuit CR103 (GY/BU) or RR103 (VT/GN). GO to H88.

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H47 CHECK THE PASSENGER AIR BAG MODULE LOOP 1 FAULT PIDs (2293_27_OD) AND (2293_25_OD) FOR A CHANGE IN FAULT STATUS

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 system 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 (Air Bag Circuit Open - Loop No. 1, Front Passenger Side)
- 2293_27_OD (Air Bag Circuit Short to Ground - Loop No. 1, Front Passenger Side)
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the passenger air bag module disconnected, open circuit faults would normally be retrieved for loop 1 and loop 2.
- Did the passenger air bag module loop 1 on-demand fault PIDs change from indicating a short to ground to an open circuit fault?

Yes
GO to H78.

No
GO to H48.

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H48 CHECK 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 resistance between RCM:
- C310a-1, circuit CR103 (GY/BU), harness side and ground.
- C310a-2, circuit RR103 (VT/GN), harness side and ground.

- Are resistances greater than 10,000 ohms?

Yes
GO to H80.

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 CR103 (GY/BU) or RR103 (VT/GN). GO to H88.

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H49 CHECK PASSENGER AIR BAG MODULE LOOP 1 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: Passenger Air Bag Module C256.
- Disconnect: RCM C310a and C310b.
- Repower the SRS. Do not prove out the system at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Measure voltage between passenger air bag module:
- C256-3, circuit CR103 (GY/BU), harness side and ground.
- C256-4, circuit RR103 (VT/GN), 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 CR103 (GY/BU) or RR103 (VT/GN). GO to H88.

No
GO to H80.

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H50 CHECK PASSENGER AIR BAG MODULE LOOP 2 RESISTANCE PID (P_ABAGR2)

- Enter the following diagnostic mode on the scan tool: DataLogger - RCM - PID.
- Enter the following diagnostic mode on the scan tool: P_ABAGR2 (Passenger Side Air Bag #2 Resistance) Resistance PID.
- Does the resistance PID value read between 1.31 and 4.29 ohms?

Yes
GO to H80.

No
GO to H51.

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H51 CHECK PASSENGER AIR BAG MODULE LOOP 2 RESISTANCE PID (P_ABAGR2) WHILE CARRYING OUT A HARNESS TEST

- NOTE: Do not remove the passenger air bag module from its mounted position at this time.
- With the passenger air bag in its mounted position, continue monitoring the P_ABAGR2 (Passenger Side Air Bag #2 Resistance) resistance PID while carrying out a harness test of the passenger air bag module circuits and accessible connectors (including any inline connectors), by wiggling connectors and flexing the wire harness.
- Does the resistance PID value read between 1.31 and 4.29 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 H88.

No
If the passenger air bag module loop 2 resistance PID is less than 1.31 ohms, GO to H52.

If the passenger air bag module loop 2 resistance PID is greater than 4.29 ohms, GO to H54.

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H52 CHECK PASSENGER AIR BAG MODULE LOOP 2 FAULT PIDs (2293_16_OD) AND (2293_17_OD) FOR A CHANGE IN FAULT STATUS

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 system 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_16_OD (Air Bag Inflator Circuit Resistance Low - Loop No. 2, Front Passenger Side)
- 2293_17_OD (Air Bag Circuit Open - Loop No. 2, Front Passenger Side)
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the passenger air bag module disconnected, open circuit faults would normally be retrieved for loop 1 and loop 2.
- Did the passenger air bag module loop 2 on-demand fault PIDs change from indicating a low resistance to an open circuit fault?

Yes
GO to H78.

No
GO to H53.

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H53 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 resistance between RCM C310a pin 5 and C310a pin 6, component side.

- Is resistance greater than 10,000 ohms?

Yes
REPAIR circuits CR104 (YE/GY) and RR104 (WH/BU). GO to H88.

No
GO to H80.

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H54 CHECK PASSENGER AIR BAG MODULE LOOP 2 FAULT PIDs (2293_17_OD) AND (2293_16_OD) FOR A CHANGE IN FAULT STATUS

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 CR104 (YE/GY), harness side and C256-2, circuit RR104 (WH/BU), harness side.
- Repower the SRS. Do not prove out the system 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_16_OD (Air Bag Inflator Circuit Resistance Low - Loop No. 2, Front Passenger Side)
- 2293_17_OD (Air Bag Circuit Open - Loop No. 2, Front Passenger Side)
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the passenger air bag module loop 2 circuits shorted together, a low resistance fault would normally be retrieved for loop 2. Loop 1 will show an open circuit fault due to the passenger air bag module being disconnected.
- Did the passenger air bag module loop 2 on-demand fault PIDs change from indicating an open circuit to a low resistance fault?

Yes
GO to H78.

No
GO to H55.

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H55 CHECK PASSENGER AIR BAG MODULE LOOP 2 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 jumper wire from passenger air bag module C256.
- Disconnect: RCM C310a and C310b.
- Measure resistance between RCM C310a-5, circuit CR104 (YE/GY), harness side and passenger air bag module C256-1, circuit CR104 (YE/GY), harness side.

- Measure resistance between RCM C310a-6, circuit RR104 (WH/BU), harness side and passenger air bag module C256-2, circuit RR104 (WH/BU), harness side.

- Are resistances less than 0.5 ohm?

Yes
GO to H80.

No
REPAIR circuit CR104 (YE/GY) or RR104 (WH/BU). GO to H88.

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H56 CHECK PASSENGER AIR BAG MODULE LOOP 2 FAULT PIDs (2293_19_OD) AND (2293_17_OD) FOR A CHANGE IN FAULT STATUS

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 system 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_17_OD (Air Bag Circuit Open - Loop No. 2, Front Passenger Side)
- 2293_19_OD (Air Bag Circuit Short to Ground - Loop No. 2, Front Passenger Side)
- DIAGNOSTIC TIP: When viewing DTC B2293 on-demand fault PIDs with the passenger air bag module disconnected, open circuit faults would normally be retrieved for loop 1 and loop 2.
- Did the passenger air bag module loop 2 on-demand fault PIDs change from indicating a short to ground to an open circuit fault?

Yes
GO to H78.

No
GO to H57.

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H57 CHECK PASSENGER 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 resistance between RCM:
- C310a-5, circuit CR104 (YE/GY), harness side and ground.
- C310a-6, circuit RR104 (WH/BU), harness side and ground.

- Are resistances greater than 10,000 ohms?

Yes
GO to H80.

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 CR104 (YE/GY) or RR104 (WH/BU). GO to H88.

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H58 CHECK PASSENGER 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: Passenger Air Bag Module C256.
- Disconnect: RCM C310a and C310b.
- Repower the SRS. Do not prove out the system at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Ignition ON.
- Measure voltage between passenger air bag module:
- C256-1, circuit CR104 (YE/GY), harness side and ground.
- C256-2, circuit RR104 (WH/BU), harness side and ground.