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 39: Replace AOS (Automatic Occupancy Sensing)
DTC B0081 3A: Incorrect AOS Installed (Automatic Occupancy Sensing)
DTC B0081 5A: AOS Not Configured (Automatic Occupancy Sensing)
DTC B0081 71: AOS Range/Performance (Automatic Occupancy Sensing)

### 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 SDM will also request the instrument panel cluster to illuminate both of the PASSENGER AIR BAG ON/OFF indicators for 5 seconds. If the SDM detects that the PPS 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

Any of the following conditions must exist for 1 second:

#### B0081 39

The SDM has received a fault message from the PPS.

#### B0081 3A

The SDM has received a message from the PPS indicating a vehicle and PPS mismatch.

#### B0081 5A

• | When the enabled state between the PPS and the SDM does not match.

• | The SDM signal stating the passenger status data received is not valid within 2.6 seconds after the PPS changes occupant classification.

#### B0081 71

The SDM has received invalid or no 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 disable.

### 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

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

Component Connector End Views

#### Description and Operation

SIR System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Testing for Intermittent Conditions and Poor Connections

• | Connector Repairs

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

Important:

• | A DTC B0081 set in history may not clear until the PPS module enters the sleep mode.

• | When removing connectors inspect for damage, corrosion or poor connection. Damage or corrosion in the following requires repair or replacement of the affected component/connector.

• | PPS module

• | SDM module

• | PPS module harness connector

• | SDM wiring harness connector

1. Ignition ON, retrieve DTCs from the PPS.
2. Verify that DTC B0081 3A is not set as current.

⇒ | If DTC B0081 3A is current, replace the PPS with the correct part number.

3. Verify that DTC B0081 5A is not set as current.

⇒ | If DTC B0081 5A is set as current, replace the PPS.

4. Verify DTC B0081 39 is not set as current.

⇒ | If DTC B0081 39 is current, replace the PPS.

5. Verify DTC B1000 or B1001 is not set as current.

⇒ | If DTC B1000 or B1001 is current, refer to DTC B1000 or DTC B1001.

6. Verify DTC B0081 71 is not set.

⇒ | If DTC B0081 71 is set, clear the SDM DTCs. No other repairs are necessary.

#### Clearing DTC B0081

1. To enter the sleep mode, remove the scan tool, turn the ignition OFF, open and close the driver door.
2. With the ignition OFF and all doors closed, wait 30 seconds.
3. Clear DTC B0081. The DTC should now be cleared.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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