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 Descriptors

DTC B0081 0F: Passenger Presence System Erratic
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 passenger presence system (PPS) and 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 PPS. The PPS will respond by commanding both of the PASSENGER AIR BAG ON/OFF indicators ON for 5 seconds. If the SDM determines the correct PPS is installed and functioning normally, the SDM will turn the passenger side airbag(s) ON or OFF based on messages from the PPS. The SDM will also send a message to the instrument panel cluster to turn the appropriate PASSENGER AIR BAG ON/OFF indicator on.

### 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 0F

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

• | The PPS is in assembly plant mode and the SDM is in production mode.

• | After the PPS change states, the SDM signal stating the Passenger Status Data Received is not valid within 2.6 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 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 commands the AIR BAG indicator ON via serial data communications.

• | The SDM will disable passenger airbag(s) that are suppressed for this vehicle.

• | The SDM commands the PASSENGER AIR BAG indicator to display OFF via serial data communication

### 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 a certain number of malfunction-free ignition cycles have occurred, typically 100.

### Diagnostic Aids

If either the SDM or PPS were replaced, verify that the correct part numbers were used for the vehicle application.

### 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

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

• | Scan Tool Data List

• | Scan Tool Data Definitions

### 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 PPS module

• | The SDM module

• | The PPS module harness connector

• | The SDM wiring harness connector

1. Ignition ON, Verify the passenger air bag ON/OFF indicators illuminate.

⇒ | If the indicators do not illuminate, refer to .

2. Ignition ON, verify no PPS DTCs are set.

⇒ | If any PPS DTCs are set as current or history, refer to .

3. Verify the correct PPS part number is installed in the vehicle.

⇒ | If the wrong PPS was installed, replace with the correct PPS.

4. Ignition OFF, disconnect the harness connector at the PPS module.
5. Ignition OFF, test for less then 1 ohm of resistance between the PPS module circuit terminal D and ground.

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

6. Ignition ON, verify a test lamp illuminates between the PPS module circuit terminal A and ground.

⇒ | If the test lamp does not illuminate, test the circuit for a short to ground or an open/high resistance. If circuit tests normal replace the PPS module.

7. If all circuits test normal, replace the SDM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | SIR/SRS Wiring Repairs

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