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Tahoe / Yukon Service Manual

DTC B1A7A

Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. DTC Descriptors DTC B1A7A Automatic Occupant Sensing Display Circuit/System Description When the ignition is turned ON, the K36 Restraints Control Module and the K85P Restraints Occupant Classification System Module perform tests to diagnose critical malfunctions. Upon a successful power-up mode the Restraints Control Module will illuminate both PASSENGER AIRBAG ON/OFF indicators located in the A103 Roof Console. If the Restraints Control Module detects a fault in the Restraints Occupant Classification System Module, it may disable the front passenger Airbag deployment loop, set DTC B1A7A and illuminate the AIRBAG indicator. Conditions for Running the DTC Ignition voltage is between 9–16 V. Conditions for Setting the DTC Any of the following conditions must exist for 5 s B1A7A 00 The Restraints Occupant Classification System Module Programming and Setup procedure has not been attempted/performed. Action Taken When the DTC Sets The Restraints Control Module requests the instrument cluster to illuminate the AIRBAG indicator. The passenger instrument panel Airbag deployment loop will be disabled. Conditions for Clearing the DTC The condition for setting the DTC no longer exists. A history DTC will clear once 100 malfunction-free ignition cycles have occurred. Diagnostic Aids If the Restraints Control Module or Body Control Module were replaced verify that the correct part numbers were used for the vehicle application. Reference Information Description and Operation Supplemental Inflatable Restraint System Description and Operation Scan Tool Reference Control Module References for scan tool information Circuit/System Verification

  1. Verify that U0100 — U02FF codes are not present. ⇒ If U0100 — U02FF codes are present, diagnose before continuing
  2. Verify that DTC B1A7A is not set in the K36 Restraints Control Module. ⇒ If DTC B1A7A is set in the K36 Restraints Control Module Conduct circuit system testing for short to ground, B+ and Open circuit before replacing A103 Roof Console ⇓ If DTC B1A7A is not set in the K36 Restraints Control Module
  3. A fault is not currently present and may be an intermittent condition. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Control Module References for passenger presence system replacement, programming and setup For wiring repair refer to: Wiring Repairs