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
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Passenger Presence Sensor Circuit Voltage Below Threshold
DTC B0074 07
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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 in the passenger presence module. When the passenger presence module detects a fault, it will illuminate 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 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 passenger presence module detects a failure within itself.
Action Taken When the DTC Sets
* The passenger presence module will set a DTC, and then communicate with the SDM.
* The SDM disables the passenger instrument panel air bag deployment loop.
* The passenger presence module 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.
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 1-2 Shift Solenoid (SS) Valve (M30)
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
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 passenger presence sensor.
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 Control Module References for passenger presence system replacement, setup, and programming