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.

### DTC Descriptor

DTC 064: Communication/ID Performance

### Circuit/System Description

The passenger presence system (PPS) communicates over a serial data communication circuit to the inflatable restraint sensing and diagnostic module (SDM). When the ignition is turned ON, the PPS module will check to make sure the PPS verification ID matches that stored in the SDM. If the SDM cannot communicate with the PPS, the SDM will set a DTC and request the instrument panel cluster (IPC) to illuminate the AIR BAG warning indicator. If the SDM can communicate to the PPS but the verification ID does not match, the PPS will set DTC 064 and notify the SDM that a fault has occurred. The SDM will then set DTC B0081 indicating a problem within the PPS and will suppress the deployment of the instrument panel (I/P) module and then illuminate the AIR BAG warning indicator.

### Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

### Conditions for Setting the DTC

• | The PPS has lost communications with the SDM.

• | The PPS verification ID does not match the ID that is stored in the SDM.

### Action Taken When the DTC Sets

• | The PPS will set a DTC, and then communicate with the SDM.

• | The SDM will set DTC B0081.

• | The SDM disables the I/P module deployment loop.

• | The PPS will illuminate the passenger air bag status OFF indicator.

• | The SDM requests the instrument panel cluster (IPC) to illuminate the AIR BAG warning indicator.

### Conditions for Clearing the DTC

• | The condition for setting the DTC no longer exists.

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

### Diagnostic Aids

The SDM has received an incorrect PPS verification ID. The SDM will continue to request the verification ID from the PPS for 5 seconds. If the SDM does not communicate or receive the correct verification ID from the PPS within 5 seconds, the SDM will set DTC B0081 as current.

### Reference Information

#### Schematic Reference

SIR Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

SIR System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### 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.

• | PPS module

• | SDM module

• | PPS wiring harness connector

• | SDM wiring harness connector

1. Ignition OFF, disconnect the harness connector at the PPS module and the SDM.
2. Test for less than 1.0 ohm between the serial data circuit terminal 18 at the PPS harness connector and terminal 60 at the SDM harness connector.

⇒ | If greater than the specified range, test the signal circuit for an open/high resistance.

3. If all circuits test normal, test or replace the PPS module.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | SIR/SRS Wiring Repairs

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