B0074

DTC B0074

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.

DTC Descriptors
DTC B0074 03
- Passenger Occupant Classification Sensor Circuit Voltage Below Threshold

DTC B0074 07
- Passenger Occupant Classification Sensor Circuit Voltage Above Threshold

DTC B0074 08
- Passenger Occupant Classification Sensor Circuit Signal Invalid

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.
* 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 indicator ON.

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 ([1][2]Air Bag Systems)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

SIR System Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information

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 harness connector at the PPS module.
2. Ignition OFF, test for less than 1 ohm between the ground circuit terminal D and ground.

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

3. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal A and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

4. Reconnect all PPS components and perform the Passenger Presence System Rezeroing. Verify DTC B0074 is not set as current.

• If DTC B0074 is set, replace the PPS.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* SIR/SRS Wiring Repairs (Component Tests and General Diagnostics)
* Control Module References (Programming and Relearning)for PPS replacement, setup, and programming