For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### Circuit/System Description

The inflatable restraint sensing and diagnostic module (SDM) sends the status of the passenger seat belt switch to the Passenger Air Bag ON/OFF indicator via a serial data communication message. The body control module (BCM) controls the passenger seat belt indicator by using the serial data communication message from the SDM. If the seat belt is unfastened, only if an occupant is seated in the front passenger seat, the SDM will send a message to the BCM to illuminate the fasten safety belt indicator for 72 seconds or until the seat belt is fastened.

### Reference Information

#### Schematic Reference

Seat Belt Schematics

#### Connector End View Reference

Seat Belt 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 BCM module

• | The seat belt switch - right

• | The SDM module

• | The seat belt switch - right wiring harness connector

• | The SDM wiring harness connector

1. Observe the Passenger Air Bag ON/OFF status indicator located in the instrument panel (I/P). Turn ON the ignition, both ON and OFF indicators will turn ON for 5 seconds. Verify that the Passenger Air Bag ON/OFF status indicator illuminates.

⇒ | If the Passenger Air Bag ON/OFF status indicator does not illuminate, refer to Passenger Presence System Indicator Circuit Malfunction .

2. Sit in the front passenger seat with the ignition ON and observe the Passenger Air Bag ON/OFF indicator, which contains the passenger seat belt indicator. Monitor the passenger seat belt indicator while buckling and unbuckling the passenger seat belt. The passenger seat belt indicator should turn OFF and ON when the passenger seat belt is unbuckled and buckled. Verify that the passenger seat belt indicator turns ON and OFF.

⇒ | If the indicator does perform as described, turn OFF the ignition, then remove the SDM connector and the passenger seat belt buckle connector. Refer to SDM replacement in Repair Instructions for connector location.

⇒ | Test and repair both seat belt switch - right signal and ground circuit for an open, high resistance. If both circuits test normal then replace the seat belt switch - right.

3. Ignition OFF, remove the BCM connector and the Passenger Air Bag ON/OFF connector. Refer to Inflatable Restraint Instrument Panel Module Indicator Replacement . Test the Passenger Seat Belt Indicator Control circuit between the SDM and the passenger seat belt for an open or high resistance. Verify that an open or high resistance does not exist.

⇒ | If any of the above conditions are found, make the appropriate repair.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Front Seat Belt Buckle Replacement

• | Inflatable Restraint Instrument Panel Module Indicator Replacement

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