Buick Regal: 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 0D
Passenger Presence Sensor Resistance Above Threshold
DTC B0074 0E
Passenger Presence Sensor Resistance Below Threshold
DTC B0074 0F
Passenger Presence Sensor Erratic (Wet Seat)
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 0D
The passenger presence module has detected a resistance above threshold.
B0074 0E
The passenger presence module has detected a resistance below threshold.
B0074 0F
The passenger presence module has detected a wet seat fault.
Action Taken When the DTC Sets
The inflatable restraint sensing and diagnostic module requests the
instrument panel cluster 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 inflatable restraint sensing and diagnostic module or
passenger presence module 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, power inverter, 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
Reference Information
Schematic Reference
SIR Wiring Schematics
Connector End View Reference
Component Connector End View Index
Description and Operation
Supplemental Inflatable Restraint System Description and Operation
Electrical Information Reference
- Circuit Testing
- Testing for Intermittent Conditions and Poor Connections
- Connector Repairs
- Wiring Repairs
Scan Tool Reference
Refer to Control Module References for scan tool information.
Circuit/System Verification
NOTE: This system is serviced as a kit (seat foam, module and/or
sensing mat).
Perform a Passenger Presence System Preload whenever a component is
replaced, refer to Passenger Presence System Re-Zeroing. Inspect component
connectors for damage or corrosion. Repair or replace the affected
component/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 DTC remains current while moving the passenger seat forward and
backward through it's full
range of motion.
- If the DTC changes to History
If the status changes this could be indication of a seat to vehicle
harness connection issue, refer to
Circuit/System Testing.
- Go to next step: If the DTC remains Current
2. Verify with the scan tool, the fault does not change status while moving
the harness near each connector
listed below.
- K85 Passenger Presence Module
- B60 Passenger Presence Sensor
- Any seat harness inline
- Inspect each connector terminal for damage or corrosion and repair as
necessary.
- Ensure each connector and CPA is correctly seated.
- Go to next step: If the status does not change
3. 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 whenever a component is
replaced, refer to Passenger Presence System Re-Zeroing. Inspect component
connectors for damage or corrosion. Repair or replace the affected
component/connector:
1. Confirm that all passenger presence system connectors are fully seated.
2. Verify that DTC B0074 0F is not set.
NOTE: 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 B60 Passenger
Presence Sensor. Clear passenger presence module DTCs.
- Verify there are no electronic devices on the passenger seat.
- Completely empty the passenger seat of any objects
- Go to next step: If the seat is empty
- 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.
- Go to next step: If the seat is dry
- If the DTC is history, do not replace B60 Passenger Presence Sensor, and
clear passenger presence
module DTCs.
- Go to next step: DTC B0074 0F does not set.
3. Verify DTC B0074 00, B0074 0D or B0074 0E is not set.
- DTC B0074 00, B0074 0D or B0074 0E is set.
Replace the K85 Passenger Presence Module.
- Go to next step: DTC B0074 00, B0074 0D or B0074 0E do not set.
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
READ NEXT:
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.
Diag
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.
Diag
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.
Diag
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