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 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
DTC B0074 11: Passenger Occupant Classification Sensor Circuit Above Maximum Threshold

### Circuit/System Description

The passenger presence system (PPS) uses a sensor mat located underneath the passenger seat cushion to measure the weight of the occupant sitting in the front passenger seat. The PPS continually monitors itself and if a fault occurs, a DTC will set. When the PPS detects a fault, it will turn ON the OFF indicator on the PASSENGER AIR BAG ON/OFF indicators. Then the PPS will communicate to the SDM through serial data communications that a PPS fault is present. The SDM will then suppress the deployment of the instrument panel (I/P) module and then turn the AIR BAG indicator ON.

### Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

### Conditions for Setting the DTC

The PPS detects a failure within itself.

### Action Taken When the DTC Sets

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

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

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

• | The SDM commands ON the AIR BAG warning lamp via serial data communications.

### Conditions for Clearing the DTC

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

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

### Reference Information

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

### 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 PPS module wiring harness connector

1. Ignition OFF, Disconnect the PPS module harness connector.
2. Ignition OFF, test for less then 1 ohm of resistance between the PPS sensor ground circuit and ground.

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

3. Ignition ON, verify a test lamp illuminates between the PPS B + 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.

4. Reconnect all PPS components and perform the Passenger Presence System Rezeroing .
5. Verify DTC B0074 does not exist.

⇒ | If DTC B0074 is set, replace the PPS.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | SIR/SRS Wiring Repairs

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