GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2008 🢒 Epica 🢒 Body Systems 🢒 Fixed and Moveable Windows 🢒 DTC B2502

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using the diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B2502 :  Passenger Air Bag Disabled Indicator Circuit Malfunction

Circuit/System Description

When the ignition switch is turned to ON, the sensing and diagnostic module (SDM) will perform a turn-on test to diagnose critical malfunctions within the SDM itself.

At this time, the SDM will establish communication with the passenger presence detection (PPD)/seat belt reminder (SBR) and the PPD/SBR will respond to the SDM by commanding the passenger air bag OFF indicator On for 5 seconds.

Conditions for Running the DTC

Ignition voltage is within the normal operating voltage range.

Conditions for Setting the DTC

The passenger OFF indicator lamp does not properly blink ON and OFF.

Action Taken When the DTC Sets

The SDM commands the air bag indicator ON.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Reference Information

Schematic Reference

SIR Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Circuit/System Testing

    Important: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.

       • The I/P module
       • The SDM module
       • The I/P wiring harness connector
       • The SDM wiring harness connector

  1. Disconnect the passenger air bag/seat belt warning lamp connector.
  2. Ignition ON, check for 9-16V at terminal 5 of the passenger air bag/seat belt warning lamp connector.
    3. ⇒If voltage is not as specified, test circuit for an open, high resistance or short to ground.
  3. Inspect the connection between terminal 5 and terminal  6 (LHD), terminal 1 (RHD) of the passenger air bag/seat belt warning lamp.
    4. ⇒If connection is not ok, replace the passenger air bag/seat belt warning lamp.
  4. Ignition OFF, disconnect the connector of the sensing and diagnostic module (SDM).
  5. Check for 0 ohms between terminal  6 (LHD), terminal 1 (RHD) of the passenger air bag/seat belt warning lamp and terminal 56 of the SDM connector.
    6. ⇒If resistance is not as specified, test circuit for an open or high resistance.
  6. Check for infinite ohms between the terminal 56 of the SDM connector and ground, battery positive.
    7. ⇒If resistance is not as specified, test circuit for a short to ground or short to voltage.
    ⇒If resistance is as specified, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for SDM replacement, setup, and programming