Pinpoint Test G: LFC 53/DTC B1892
Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS)
Pinpoint Tests
Pinpoint Test G: LFC 53/DTC B1892
Refer to Wiring Diagram Set 46, Supplemental Restraint System for schematic and connector information. Diagrams By Number
Normal Operation
The connection between the Instrument Cluster (IC) module and Restraints Control Module (RCM) is used to signal a chime if the primary air bag warning indicator is inoperative and another Supplemental Restraint System (SRS) fault exists. The RCM monitors this connection to the IC module at C220 pin 23.
If the RCM detects a circuit failure on the connection to the IC module, it will store DTC B1891 in memory and flash Lamp Fault Code (LFC) 53 (or a higher priority code if one exists) on the air bag warning indicator.
- DTC B1892 Air Bag Tone Warning Indicator Circuit Failure - If the RCM detects an open circuit or short to ground on the air bag tone warning indicator circuit, it will set this DTC.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- IC module
- RCM
PINPOINT TEST G: LFC 53/DTC B1892
WARNING: Remove restraint system diagnostic tools from the vehicle prior to road testing. If tools are not removed, the supplemental restraint system (SRS) device may not deploy in a crash. Failure to follow this instruction may result in serious personal injury or death in a crash and possibly violate vehicle safety standards.
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: 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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G1 RETRIEVE RCM DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was RCM DTC B1892 retrieved on-demand during the self test?
Yes
This fault cannot be cleared until it is corrected and the DTC is no longer retrieved during the on-demand self test. GO to G2.
No
This is an intermittent fault when present as a CMDTC only. The fault condition is not present at this time. GO to G5.
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G2 CHECK THE AIR BAG TONE WARNING INDICATOR CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Depower the SRS. Refer to Supplemental Restraint System (SRS) Depowering and Repowering Supplemental Restraint System (SRS) Depowering and Repowering.
- Disconnect: RCM C2041a and C2041b.
- Disconnect: IC Module C220.
- Measure the resistance between IC module C220-23, circuit 1083 (LB/BK), harness side and ground.
- Is resistance greater than 10,000 ohms?
Yes
GO to G3.
No
REPAIR circuit 1083 (LB/BK). GO to G6.
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G3 CHECK THE AIR BAG TONE WARNING INDICATOR CIRCUIT FOR AN OPEN
- Measure the resistance between RCM C2041a-22, circuit 1083 (LB/BK), harness side, and IC module C220-23, circuit 1083 (LB/BK), harness side.
- Is resistance less than 5 ohms?
Yes
GO to G4.
No
REPAIR circuit 1083 (LB/BK). GO to G6.
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G4 CHECK THE AIR BAG TONE WARNING INDICATOR
- Deactivate the SRS. Refer to Supplemental Restraint System (SRS) Deactivation and Reactivation Supplemental Restraint System (SRS) Deactivation and Reactivation.
- Connect: IC Module C220.
- Ignition ON.
- Measure the voltage between RCM C2041a-22, circuit 1083 (LB/BK), harness side and ground.
- Is voltage greater than 10 volts?
Yes
INSTALL a new RCM. REFER to Restraints Control Module (RCM) Service and Repair. GO to G6.
No
INSTALL a new IC module. GO to G6.
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G5 CHECK FOR AN INTERMITTENT FAULT
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Was RCM DTC B1892 retrieved on-demand during the self test?
Yes
GO to G2.
No
CHECK for causes of intermittent open or short to ground on circuit 1083 (LB/BK). ATTEMPT to recreate the hard fault by flexing the wire harness and cycling the ignition 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 G6.
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G6 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.
- If previously directed to deactivate the SRS, reactivate the SRS. Do notprove out the SRS at this time. Refer to Supplemental Restraint System (SRS) Deactivation and Reactivation Supplemental Restraint System (SRS) Deactivation and Reactivation.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - RCM.
- Are any RCM DTCs retrieved on-demand during the self test?
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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