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Pinpoint Test B: DTC B1048




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

Pinpoint Tests

Pinpoint Test B: DTC B1048

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

Normal Operation

The Restraints Control Module (RCM) monitors all deployable devices for a cross link fault between deployable circuits. If the RCM detects a fault between the circuits of one deployable device and another deployable device, it will store a DTC for each of the cross linked loops indicating a fault. The RCM sends a message to the Instrument Cluster (IC) module to flash a Lamp Fault Code (LFC) of the cross link DTCs (or higher priority code if one exists) on the air bag warning indicator. When a normal squib fault is present (one squib is either shorted to battery/ground, has an open circuit or has low resistance), then cross link diagnostics will not be active. Once the normal squib fault is repaired, then the cross link diagnostics will resume.





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



PINPOINT TEST B: DTC B1048

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: 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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B1 RETRIEVE RCM DTCs


- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was DTC B1048 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.

For DTC B1048 and DTC:

B1049, GO to B2.

B1054, GO to B3.

B1057, GO to B4.

No
This is an intermittent fault when present as a Continuous Memory Diagnostic Trouble Code (CMDTC) only. GO to B6.

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B2 CHECK RESISTANCE BETWEEN THE PASSENGER AIR BAG MODULE CIRCUITS AND THE PASSENGER SAFETY BELT RETRACTOR PRETENSIONER 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.
- Disconnect: Passenger Safety Belt Retractor Pretensioner C303.
- Measure the resistance between RCM:
- C310A-1, circuit CR103 (GY/BU), harness side and RCM C310B-33, circuit RR122 (BN), harness side.
- C310A-1, circuit CR103 (GY/BU), harness side and RCM C310B-34, circuit CR122 (WH/OG), harness side.
- C310A-2, circuit RR103 (VT/GN), harness side and RCM C310B-33, circuit RR122 (BN), harness side.
- C310A-2, circuit RR103 (VT/GN), harness side and RCM C310B-34, circuit CR122 (WH/OG), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to B5.

No
REPAIR the affected circuits. GO to B7.

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B3 CHECK RESISTANCE BETWEEN THE PASSENGER AIR BAG MODULE CIRCUITS AND THE DRIVER SAFETY BELT RETRACTOR PRETENSIONER 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.
- Disconnect: Driver Safety Belt Retractor Pretensioner C323.
- Measure the resistance between RCM:
- C310A-1, circuit CR103 (GY/BU), harness side and RCM C310B-31, circuit CR120 (BU/OG), harness side.
- C310A-1, circuit CR103 (GY/BU), harness side and RCM C310B-32, circuit RR120 (BN/GN), harness side.
- C310A-2, circuit RR103 (VT/GN), harness side and RCM C310B-31, circuit CR120 (BU/OG), harness side.
- C310A-2, circuit RR103 (VT/GN), harness side and RCM C310B-32, circuit RR120 (BN/GN), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to B5.

No
REPAIR the affected circuits. GO to B7.

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B4 CHECK RESISTANCE BETWEEN THE PASSENGER AIR BAG MODULE CIRCUITS AND THE DRIVER 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: RCM C310A and C310B.
- Disconnect: Passenger Air Bag Module C256.
- Remove the driver air bag module. Refer to Driver Air Bag Module Driver Air Bag Module.
- Measure the resistance between RCM:
- C310A-1, circuit CR103 (GY/BU), harness side and RCM C310A-3, circuit RR101 (YE/GN), harness side.
- C310A-1, circuit CR103 (GY/BU), harness side and RCM C310A-4, circuit CR101 (VT/BN), harness side.
- C310A-2, circuit RR103 (VT/GN), harness side and RCM C310A-3, circuit RR101 (YE/GN), harness side.
- C310A-2, circuit RR103 (VT/GN), harness side and RCM C310A-4, circuit CR101 (VT/BN), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to B5.

No
REPAIR the affected circuits. GO to B7.

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B5 CONFIRM THE RCM FAULT


- 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.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was DTC B1048 retrieved on-demand during self-test?

Yes
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to B7.

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. REPAIR any intermittent wiring, terminal or connector concerns found. GO to B6.

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B6 CHECK FOR AN INTERMITTENT FAULT


- Disconnect: Passenger Air Bag Module C256.
- If DTC B1049 is also present continuous:
- Disconnect the passenger safety belt retractor pretensioner C303.
- If DTC B1054 is also present continuous:
- Disconnect the driver safety belt retractor pretensioner C323.
- If DTC B1057 is also present continuous:
- 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.
- DIAGNOSTIC TIP: When viewing DTCs with SRS components disconnected, open circuit faults would normally be retrieved.
- Was DTC B1048 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.

For DTC B1048 and DTC:

B1049, GO to B2.

B1054, GO to B3.

B1057, GO to B4.

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. 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 B7.

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B7 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 indicating a fault?

Yes
Do not clear any DTCs until all DTCs have been resolved. GO to the DTC Chart for pinpoint test direction. Diagnostic Trouble Code Tests and Associated Procedures

No
CLEAR all RCM CMDTCs. PROVE OUT the SRS. Repair is complete. RETURN the vehicle to the customer.

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