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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 00
- Passenger Occupant Classification Sensor

DTC B0074 0D
- Passenger Occupant Classification Sensor Circuit Resistance Above Threshold

DTC B0074 0E
- Passenger Occupant Classification Sensor Circuit Resistance Below Threshold

DTC B0074 0F
- Passenger Occupant Classification Sensor Circuit Erratic (Wet Seat)

Diagnostic Fault Information





Circuit/System Description

The passenger presence system (PPS) sensor continually monitors itself and if a fault in this circuit occurs, a DTC will set. When the sensing and diagnostic module (SDM) detects this DTC within the PPS, it will notify the customer of the enable/disable status by illuminating 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 disable the deployment of the instrument panel (I/P) module and then illuminate the AIR BAG warning indicator.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

* The PPS detects the voltage at the pressure sensor signal is less than 0.5 volts or greater than 4.5 volts for 500 milliseconds.
* The PPS detects the voltage at the pressure sensor voltage reference is less than 4.5 volts or greater than 9.1 volts for 500 milliseconds.
* The PPS detects the amperage at the PPS sensor low reference is 25 mA or greater for 500 milliseconds.

Action Taken When the DTC Sets

* The SDM disables the I/P module deployment loop.
* The SDM will illuminate the OFF portion of the PASSENGER AIR BAG ON/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 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:


* PPS pressure sensor

* PPS pressure sensor wiring harness connector


1. Verify that DTC B0074 0F is not set.

If the DTC is set, verify the seat is dry. If the seat is wet, allow 24-48 hours dry time.

2. Ignition OFF, disconnect the harness connector at the PPS sensor.
3. Test for less then 10 ohms between the ground circuit terminal D and ground.

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

4. 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.

5. Reconnect all PPS components and perform the Passenger Presence System Preload Test (Programming and Relearning) procedure.
6. Clear DTCs, verify DTC B0074 is not set.

If the DTC sets, replace the PPS sensor.

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