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 00
- Passenger Presence Sensor

DTC B0074 0D
- Passenger Presence Sensor Circuit Resistance Above Threshold

DTC B0074 0E
- Passenger Presence Sensor Circuit Resistance Below Threshold

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

Circuit/System Description

The passenger presence sensor continually monitors itself and if a fault in this circuit occurs, a DTC will set in the passenger presence module. When the inflatable restraint sensing and diagnostic module (SDM) detects this DTC within the passenger presence module, 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 passenger presence module will communicate to the SDM through serial data communications that a PPS fault is present. The SDM will then disable the deployment of the passenger instrument panel air bag and then illuminate the AIR BAG warning indicator.

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 module.
* The passenger presence module detects a wet seat fault if DTC B0074 0F is set.

Action Taken When the DTC Sets

* The SDM disables the passenger instrument panel air bag 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.

Diagnostic Aids

* If either the SDM or PPS were replaced verify that the correct part numbers were used for the vehicle application.
* If this DTC is set as either current or history it may have been caused by an electronic device. If an electronic device (Computers, MP3 Players, Cell Phones, Diagnostic Scan Tool, etc.) was placed on the passenger seat the passenger presence module may command the passenger air bag indicator to turn on and/or command the passenger seat belt indicator to turn on. Make sure there are no objects on the passenger seat and clear the DTCs. If this DTC resets then perform this diagnostic. If the DTC does not reset there is no further work needed on the passenger presence system.
* If this DTC is set as either current or history it may have been caused by an aftermarket seat heater. The aftermarket seat heater may command the passenger air bag indicator to turn on and/or command the passenger seat belt indicator to turn on. Remove the aftermarket seat heater from the passenger seat and clear the DTCs. If this DTC resets then perform this diagnostic. If the DTC does not reset there is no further work needed on the passenger presence system.

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 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 Control Module References for scan tool information

Circuit/System Testing

Note: The passenger presence system (PPS) is a calibrated unit. When replacing the assembly all parts in the service kit must remain together. Do not mix any of the old parts with the new parts. PPS comes in as part of a service kit which contains a seat foam, presence sensor and a electronic control unit (ECU) module (if applicable).

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 module
* Passenger presence sensor wiring harness

1. Verify that no other passenger presence module DTCs are set.

• If other passenger presence module DTCs are set, investigate those DTCs first.

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

• If this DTC is set, verify there are no electronic devices on the passenger seat. If not, then verify the seat is dry by removing the trim from the seat bottom frame. IF the seat is wet, allow 24-48 hours dry time with trim completely off. If the DTC is history, do not replace the passenger presence module. Clear the passenger presence module codes.

3. Verify that DTC B0074 00, B0074 0D, or B0074 0E is not set.

• If any of the DTCs are set then replace the passenger presence module.

Repair Instructions

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

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