SAAB WIS ONLINE

DTC B0074

DTC B0074

Diagnostic Instructions


• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• Diagnostic Procedure Instructions provides an overview of each diagnostic category.


DTC Descriptors

DTC B0074 00

Passenger Presence Sensor Circuit Malfunction

DTC B0074 04

Passenger Presence Sensor Open

Circuit/System Description

The passenger presence module monitors the sensor status continually. Whenever the sensor mat has an internal malfunction, the passenger presence module will set DTC B0074.

Conditions for Running the DTC

Ignition voltage is between 9-16 V.

Conditions for Setting the DTC

B0074 00

The passenger presence module has detected a disconnection from the sensor mat.

B0074 04

The passenger presence module has detected an open circuit.

The passenger presence module has received a fault signal from the sensor mat.

Action Taken When the DTC Sets

The SDM requests the instrument panel cluster to illuminate the AIR BAG indicator.

Conditions for Clearing the DTC


• The condition responsible 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 returns 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 returns 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

Connector End View Reference

Component Connector End Views

Description and Operation

SIR System Description and Operation

Electrical Information Reference


• Circuit Testing

• Testing for Intermittent Conditions and Poor Connections

• Connector Repairs

• Wiring Repairs


Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Note

This system allows you to service each component separately (module and sensor/sensor harness). Perform a preloading test on the passenger presence system whenever a component is replaced. See Passenger presence system, programming and setting . Check the following component connectors for damage or corrosion. Repair or replace the affected component/connector:

• Passenger presence sensor

• Passenger presence sensor harness connector

• Passenger presence module

• Passenger presence module harness connector

• Seat wiring harness to vehicle harness connector

The connector and connector position assurance (CPA) may seat independent of each other. Both the connector and CPA should seat with an audible and/or tactile click.



1. Verify the diagnostic trouble code B0074 remains while the following measures are taken:

• Move the passenger seat forward and back toward each end position.

• Move the wiring at K85 Passenger presence module

• Move the wiring on the passenger presence senor

• Move the wiring near the seat's wiring to vehicle's wiring harness connector

2. If diagnostic trouble code B0074 does not remain:

3. Check that each connector and CPA are correctly fitted and inspect each connector terminal for damage or corrosion and repair as necessary.

4. If diagnostic trouble code B0074 does remain:

5. Refer to Circuit/System Testing below.


Circuit/System Testing

Note

This system is serviced as a kit (seat foam, module, and/or sensing mat). Perform a Passenger Presence System Preload procedure whenever a component is replaced. Inspect the following component connectors for damage or corrosion. Repair or replace the affected component/connector:



1. Confirm that all passenger presence module and sensor connectors are fully seated.

2. Verify DTC B0074 is not set.

3. If diagnostic trouble code B0074 is registered

4. Replace K85 passenger presence module.

5. If diagnostic trouble code B0074 is not set

6. All OK.


Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

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