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 Descriptors

DTC B2501 : 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 ON 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

#### 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

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. 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.

3. Inspect the bulb of the passenger air bag ON indicator.

⇒ | If bulb is bad, replace the bulb.

⇒ | If all circuits test normal, replace the clock assembly.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Steering Wheel Inflatable Restraint Module Coil Replacement

• | Steering Wheel Inflatable Restraint Module Replacement

• | Control Module References for SDM replacement, setup, and programming