For 1990-2009 cars

### 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.

⇒ | 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.

⇒ | 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.

⇒ | 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.

⇒ | 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