Pinpoint Test B: DTC B1868
Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)
Pinpoint Tests - Supplemental Restraint System (SRS)
Pinpoint Test B: DTC B1868
Refer to Wiring Diagram Set 46, Supplemental Restraint System for schematic and connector information. Diagrams By Number
Normal Operation
During normal operation, the Instrument Cluster (IC) module will illuminate the air bag warning indicator continuously for 6 seconds after the ignition is ON. If the Supplemental Restraint System (SRS) is fault free, the air bag warning indicator will turn off and remain off. If a fault is detected the air bag warning indicator will illuminate and remain illuminated for the rest of each key cycle until the fault is no longer detected. The Restraints Control Module (RCM) communicates to the IC module via HS-CAN. The IC module will illuminate the air bag warning indicator based on messaging from the RCM or if there is no communication between the RCM and IC module.
If the IC module detects a problem with the air bag warning indicator, it will send a fault message to the RCM. The RCM and IC module will store DTC B1868 in memory.
- DTC B1868 Lamp Air Bag Warning Indicator Circuit Failure - If the RCM receives a message from the IC module of an air bag warning indicator failure, it will set this DTC.
This pinpoint test is intended to diagnose the following:
- IC module
- RCM
PINPOINT TEST B: DTC B1868
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: 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 B1868 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 B2.
No
This is an intermittent fault when present as a continuous memory DTC only. The fault condition is not present at this time. CHECK the IC module for DTCs and REPAIR as needed. REFER to Instrumentation, Message Center, and Warning Chimes Testing and Inspection. GO to B4.
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B2 RETRIEVE IC DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - IC Module.
- Was DTC B1868 retrieved on-demand during self-test?
Yes
REFER to Instrumentation, Message Center, and Warning Chimes Testing and Inspection to diagnosis IC module concerns. GO to B4.
No
If the IC module does communicate with the scan tool, GO to B3.
If the IC module does not communicate with the scan tool, REFER to Module Communications Network Testing and Inspection to diagnose the concern. GO to B4.
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B3 CHECK IC MODULE
- Enter the following diagnostic mode on the scan tool: DataLogger - IC Module - Active Command - All_Lamp.
- Does the air bag warning indicator turn on and off when using the active command?
Yes
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to B4.
No
INSTALL a new IC module. REFER to Instrumentation, Message Center, and Warning Chimes Instrument Cluster (IC). GO to B4.
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B4 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 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 - Restraints.
- Are any RCM and/or OCSM DTCs retrieved indicating a fault?
Yes
Do not clear any DTCs until all concerns/faults have been resolved. GO to the DTC Charts for pinpoint test direction. [1][2]Diagnostic Trouble Code Descriptions
No
CLEAR all RCM and OCSM CMDTCs. PROVE OUT the SRS. Repair is complete. RETURN the vehicle to the customer.
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