B2502 (North America Vehicles)

DTC B2502 (North America Vehicles)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using the diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptors
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.

Upon passing these tests, the ignition and deployment loop voltages are measured to ensure that these voltages are within the normal ranges. The SDM monitors the voltages at the driver low and the passenger low to detect shorts to ground or voltage in the deployment loops.

The SDM tests the voltage continuously from the warning lamp terminal.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

The passenger OFF indicator lamp does not operate depending on the status of passenger presence.

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.
* A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

Reference Information
Schematic Reference

SIR Schematics (with WHB) (SIR Schematics (with WHB))SIR Schematics (without WHB) (SIR Schematics (without WHB))
Connector End View Reference

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Circuit/System Testing

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

* The steering wheel coil module
* The SDM module
* The steering wheel coil module wiring harness connector
* The SDM wiring harness connector

1. Ignition OFF, disconnect the clock assembly connector
2. Inspect the bulb of the passenger air bag ON indicator.

• If bulb is bad, replace the bulb.

3. Ignition ON, test for B+ at terminal 1 of the clock wiring connector

• If voltage is not as specified, repair the open, high resistance or short to ground in the circuit.

4. Ignition OFF, disconnect the sensing and diagnostic module (SDM) connector.
5. Test for less than 1 ohm between terminal 56 of the SDM and terminal 10 of the clock connector.

• If resistance is not as specified, repair the open or high resistance in the circuit.

• If all circuits test normal, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Steering Wheel Inflatable Restraint Module Coil Replacement (Removal and Replacement)
* Steering Wheel Inflatable Restraint Module Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for SDM replacement, setup, and programming