Pinpoint Test H: DTC B1868
Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)
Pinpoint Tests
Pinpoint Test H: 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 air bag warning indicator will illuminate continuously for approximately 6 seconds and then go out if no air bag fault exists. Control of the air bag warning indicator is a function of the Instrument Cluster (IC) module based on information it receives from the Restraints Control Module (RCM). The RCM sends a message to the IC module to turn the indicator off if no air bag fault exists. If the RCM detects a fault with the Supplemental Restraint System (SRS), it will send a message to the IC module to turn the air bag warning indicator on.
If the IC module detects a fault 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 H: DTC B1868
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: 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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H1 RETRIEVE RCM DTCs
NOTE: All RCM diagnosis will be carried out using Continuous Memory Diagnostic Trouble Codes (CMDTCs) and status information. Refer to DTC Fault Reporting and Status Information. DTC Fault Reporting and Status Information
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Select the DTC and view DTC Status information.
- Does the status information for DTC B1868 indicate a fault was present at the time of request?
Yes
This fault cannot be cleared until it is corrected and the DTC is no longer retrieved during the self-test. GO to H2.
No
This is an intermittent fault. The DTC Status information indicates the fault was not present at time of request.
REFER to Instrumentation and Warning Chimes Testing and Inspection for diagnostic direction. GO to H4.
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H2 CHECK FOR IC MODULE DTCs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - IC.
- Were any DTCs retrieved indicating a fault?
Yes
REFER to Instrumentation and Warning Chimes Testing and Inspection to diagnosis IC module concerns. GO to H4.
No
If the IC module does communicate with the scan tool, GO to H3.
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 H4.
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H3 CHECK THE IC MODULE
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - IC .
- 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 H4.
No
INSTALL a new IC module. REFER to Instrumentation and Warning Chimes Service and Repair. GO to H4.
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H4 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.
- NOTE: When selecting Restraints from the Self Test menu, DTCs will be retrieved from the RCM and OCSM.
- Select the DTC and view DTC Status information.
- Does the status information for any RCM DTC indicate a fault is present and/or are any OCSM on-demand DTCs retrieved?
Yes
Do not clear any DTCs until all DTC concerns have been resolved. GO to the DTC Charts for pinpoint test direction. Diagnostic Trouble Code Tests and Associated Procedures
No
CLEAR all RCM and OCSM CMDTCs. PROVE OUT the SRS. Repair is complete. RETURN the vehicle to the customer.
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