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 [1][2]Air Bag Systems

Connector End View Reference
Component Connector End Views

Description and Operation
SIR System Description and Operation 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/sensing mat). Perform a passenger presence system preload test procedure whenever a component is replaced. Refer to Passenger Presence System Programming and Setup. Inspect 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. Observe with the scan tool if the fault changes status while moving the passenger seat forward and backward through its full range of motion. The status should stay consistent.
2. If the status changes this could be indication of a seat to vehicle harness connection issue, refer to Circuit/System Testing.
3. Observe with the scan tool if the fault changes status while moving the harness near each connector listed below. The status should stay consistent.
- Passenger presence module
- Passenger presence sensor
- Any seat harness inline
- If the reading is erratic while moving the harness, perform the following:
- Inspect each connector terminal for damage or corrosion and repair as necessary.
- Insure each connector and CPA is correctly seated.

4. All OK.

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. Replace the K85 passenger presence module.
4. All OK.

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

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