Pinpoint Test B: DTC B1868
Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)
Pinpoint Test - 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 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) over the High Speed Controller Area Network (HS-CAN). The default mode for the air bag warning indicator is on. 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 problem 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 problem with the air bag warning indicator, it will send a fault message to the RCM and the RCM 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: 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: 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 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 Diagnostic Trouble Code (CMDTC) only. CHECK the IC module for DTCs and REPAIR as needed. REFER to Instrument Panel, Gauges and Warning Indicators. GO to B4.
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B2 CHECK IC MODULE DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - IC Module .
- Were any DTCs retrieved during self test?
Yes
REFER to Instrument Panel, Gauges and Warning Indicators to diagnose 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 Information Bus to diagnose the HS-CAN concern. GO to B4.
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B3 CHECK THE IC MODULE ACTIVE COMMAND (All_Lamp) PID
- Enter the following diagnostic mode on the scan tool: DataLogger - IC Module - All_Lamp (Active Command).
- 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 Instrument Panel, Gauges and Warning Indicators. GO to B4.
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B4 CHECK FOR ADDITIONAL SRS DTCs
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.
- Ignition OFF.
- 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 - Restraints.
- NOTE: When selecting Restraints from the Self Test menu, DTCs will be retrieved from the RCM and OCSM.
- Are any RCM and/or OCSM DTCs retrieved on-demand during self-test?
Yes
Do not clear any DTCs until all DTCs 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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