For 1990-2009 cars

### DTC Descriptor

DTC B1001: System Sensors Data Mismatch

### Diagnostic Fault Information

Perform the Diagnostic System Check - SIR prior to using this diagnostic procedure.

### Circuit/System Description

When the ignition switch is turned ON, the sensing and diagnostic module (SDM) compares the restraints ID that is stored in itself to the restraints ID that is stored in the body control module (BCM). The restraints ID that is being compared contains the last four digits of the SDM part number. The SDM then compares the VIN stored in itself to the VIN stored in the BCM.

### Conditions for Running the DTC

Ignition ON.

### Conditions for Setting the DTC

The restraints ID or VIN information stored in the SDM does not match that which is stored in the BCM.

### Action Taken When the DTC Sets

• | The airbag indicator will illuminate

• | The SDM will disable all deployment loops

### Conditions for Clearing the DTC

A current DTC will clear when the SDM and BCM data matches

### Reference Information

#### Schematic Reference

SIR Schematics

#### Connector End View Reference

SIR Connector End Views

#### Description and Operation

SIR System Description and Operation

#### Electrical Information Reference

• | Wiring Repairs

• | Connector Repairs

### Circuit/System Verification

1. Ignition ON, verify that DTC B1001 is not set.

⇒ | If the DTC is set, reprogram the BCM with the proper vehicle option content. If the DTC resets, replace the BCM.

2. Replace the SDM.

### Repair Instructions

• | Body Control Module Replacement

• | Inflatable Restraint Sensing and Diagnostic Module Replacement