B1868
Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)
Pinpoint Test H: DTC B1868
Refer to Wiring Diagrams Set 46, Supplemental Restraint System for schematic and connector information. Electrical Diagrams
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 (Restraints Control Module) sends a message to the IC (Instrument Cluster) module to turn the indicator off if no air bag fault exists. If the RCM (Restraints Control Module) detects a fault with the Supplemental Restraint System (SRS), it will send a message to the IC (Instrument Cluster) module to turn the air bag warning indicator on.
If the IC (Instrument Cluster) module detects a fault with the air bag warning indicator, it will send a fault message to the RCM (Restraints Control Module). The RCM (Restraints Control Module) and IC (Instrument Cluster) module will store DTC B1868 in memory.
- DTC B1868 (Lamp Air Bag Warning Indicator Circuit Failure)- If the RCM (Restraints Control Module) receives a message from the IC (Instrument Cluster) module of an air bag warning indicator failure, it will set this DTC.
This pinpoint test is intended to diagnose the following:
- IC (Instrument Cluster) module
- RCM (Restraints Control Module)
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 (Supplemental Restraint System) 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 (Supplemental Restraint System).
NOTE: The SRS (Supplemental Restraint System) must be fully operational and free of faults before releasing the vehicle to the customer.
H1 RETRIEVE RCM (Restraints Control Module) DTCs
NOTE: All RCM (Restraints Control Module) 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 (Restraints Control Module).
- 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 Instrument Panel, Gauges and Warning Indicators for diagnostic direction. GO to H4.
H2 CHECK FOR IC (Instrument Cluster) MODULE DTCs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test- IC (Instrument Cluster).
Were any DTCs retrieved indicating a fault?
Yes
REFER to Instrument Panel, Gauges and Warning Indicators to diagnosis IC (Instrument Cluster) module concerns. GO to H4.
No
If the IC (Instrument Cluster) module does communicate with the scan tool, GO to H3.
If the IC (Instrument Cluster) module does not communicate with the scan tool, REFER to Information Bus to diagnose the concern. GO to H4.
H3 CHECK THE IC (Instrument Cluster) MODULE
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger- IC (Instrument Cluster).
- All_Lamp
Does the air bag warning indicator turn on and off when using the active command?
Yes
INSTALL a new RCM (Restraints Control Module). REFER to Restraints Control Module (RCM) . GO to H4.
No
INSTALL a new IC (Instrument Cluster) module. GO to H4.
H4 CHECK FOR ADDITIONAL SRS (Supplemental Restraint System) 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 (Supplemental Restraint System) components (if previously disconnected).
- If previously directed to depower the SRS (Supplemental Restraint System), repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint 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- Restraints.
NOTE: When selecting Restraints from the Self Test menu, DTCs will be retrieved from the RCM (Restraints Control Module) and OCSM (Occupant Classification System Module).
- Select the DTC and view DTC Status information.
Does the status information for any RCM (Restraints Control Module) DTC indicate a fault is present and/or are any OCSM (Occupant Classification System Module) 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. Air Bag Systems / Seat Belt Systems
No
CLEAR all RCM (Restraints Control Module) and OCSM (Occupant Classification System Module) CMDTCs (Continuous Memory Diagnostic Trouble Codes). PROVE OUT the SRS (Supplemental Restraint System). Repair is complete. RETURN the vehicle to the customer.