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B0074




DTC B0074

Diagnostic Instructions

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

DTC Descriptors
DTC B0074 03
- Passenger Presence Sensor Circuit Voltage Below Threshold

DTC B0074 07
- Passenger Presence Sensor Circuit Voltage Above Threshold

DTC B0074 08
- Passenger Presence 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 illuminate 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 passenger instrument panel air bag and then illuminate the AIR BAG indicator.

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 passenger instrument panel air bag deployment loop.
* The PPS will illuminate the passenger air bag status OFF indicator.
* The SDM requests the instrument panel cluster (IPC) 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 ([1][2]Air Bag Systems)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

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

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

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:


* Passenger presence sensor

* Passenger presence sensor wiring harness connector


1. Ignition OFF, disconnect the harness connector at the passenger presence sensor.
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 (SIR/SRS Wiring Repairs)
* Control Module References (Programming and Relearning) for passenger presence sensor replacement, setup, and programming