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 and overview of each diagnostic category.

### DTC Descriptors

DTC B0081 3A: Passenger Presence System Incorrect Component Installed
DTC B0081 39: Passenger Presence System Internal Electronic Failure
DTC B0081 71: Passenger Presence System Invalid Serial Data Received

### Circuit/System Description

When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. When the SDM has completed the power-up mode, the SDM will establish communication with the passenger presence system (PPS) module. The PPS module will respond by illuminating both of the PASSENGER AIR BAG ON/OFF indicators ON for 5 seconds. The SDM will then transmit a request message to the PPS module to receive the PPS module verification ID. The PPS module will transmit the verification ID to the SDM, and the SDM will compare the ID received to data stored in memory. If the data stored in memory does not match the information transmitted by the PPS module or the SDM has detects that the PPS module has set a current DTC the SDM will then disable the instrument panel (I/P) module deployment loop, set DTC B0081 and illuminate the AIR BAG indicator.

### Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

### Conditions for Setting the DTC

All of the following conditions must exist for 5 seconds:

#### B0081 3A

• | The SDM has received an ID message from the PPS which does not match the ID stored in the SDM memory.

• | The SDM has reset the PPS module twice without detecting the correct ID message.

#### B0081 39

• | The SDM has received a NOK message from the PPS.

• | The SDM has not received a message.

#### B0081 71

The SDM has received invalid serial data from the PPS.

### Action Taken When the DTC Sets

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

• | The I/P module deployment loop will be disabled.

### 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 255 malfunction-free ignition cycles have occurred.

### Diagnostic Aids

If either the SDM or PPS module were replaced verify that the correct part numbers were used for the vehicle application as this can cause B0081.

### 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 Verification

Important: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected.

• | PPS module

• | PPS module wiring harness

• | SDM

• | SDM wiring harness

1. Verify that DTC B0081 39 is not set.

⇒ | If the DTC is set replace the PPS module.

2. Verify the correct SDM and PPS module part number are installed for the vehicle configuration.

⇒ | If an incorrect SDM or PPS module was installed, replace with the correct module.

3. Verify that no PPS DTCs are present.

⇒ | If PPS DTCs are present, refer to Diagnostic Trouble Code (DTC) List - Vehicle for the appropriate DTC diagnostic procedure.

4. Ignition ON, Verify the appropriate inflatable restraint passenger air bag ON/OFF indicator illuminates.

⇒ | If the appropriate inflatable restraint passenger air bag ON/OFF indicator does not illuminate, refer to Passenger Presence System Indicator Circuit Malfunction.

5. Verify that DTC B0081 is not set.

⇒ | If the DTC is set as current, replace the SDM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | SIR/SRS Wiring Repairs

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