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 B0074 00: Passenger Occupant Classification Sensor Circuit
DTC B0074 01: Passenger Occupant Classification Sensor Circuit Short To Battery
DTC B0074 02: Passenger Occupant Classification Sensor Circuit Short To Ground
DTC B0074 08: Passenger Occupant Classification Sensor Circuit Signal Invalid

### Diagnostic Fault Information

Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | --- | ---
Pressure Sensor Signal | B0074 02 | -- | -- | B0074 01 | B0074 00, B0074 08
Pressure Sensor Voltage Reference | B0074 02 | -- | -- | B0074 01 | B0074 00, B0074 08
Pressure Sensor Low Reference | -- | -- | -- | B0074 01 | B0074 00, B0074 08

### Circuit/System Description

When the ignition is turned ON, the passenger presence system module continually monitors the status of the passenger presence system pressure sensor. If the pressure sensor does not communicate or the passenger presence system module determines the pressure sensor has an internal malfunction DTC B0074 will set.

### Conditions for Running the DTC

Ignition voltage is between 9-16 V.

### Conditions for Setting the DTC

The SDM has received a fault message from the passenger presence system module.

### Action Taken When the DTC Sets

The SDM requests the instrument panel cluster to illuminate the AIR BAG 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.

### 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 Testing

Note: When removing connectors, inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector:

• | Passenger presence system sensor

• | SDM module

• | Passenger presence system sensor wiring harness connector

• | SDM wiring harness connector

1. Ignition OFF, disconnect the harness connector at the B60 passenger presence system sensor.
2. Disconnect the harness connector at the K36 SDM connector
3. Ignition ON, test for less than 1 V between the signal circuit terminal 2 and ground

⇒ | If greater than the specified range, test the circuit for a short to voltage.

4. Ignition ON, test for less than 1 V between the low reference circuit terminal 1 and ground

⇒ | If greater than the specified range, test the circuit for a short to voltage.

5. Test for infinite resistance between the signal circuit terminal 2 and ground

⇒ | If less than the specified value, test the circuit for a short to ground.

6. Test for less than 1 Ω between the signal circuit terminal 2 and the K36 SDM terminal listed below:

• | With RPO code AW7 terminal 47 X2

• | Without RPO code AW7 terminal 47 X3

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

7. Test for less than 1 Ωbetween the low reference circuit terminal 1 and the SDM terminal listed below:

• | With RPO code AW7 terminal 44 X2

• | Without RPO code AW7 terminal 44 X3

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

8. If all circuits test normal replace the B60 passenger presence system sensor. If the DTC resets, replace the K36 SDM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for passenger presence system and SDM replacement, setup, and programming