B1674
Seat Driver Occupied Input Circuit Short To Battery
Body Chassis/Safety Seat Occupancy Detection 🟢 Low — Fix at next service
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What This Actually Means
In plain language — no jargon

The driver seat occupancy sensor is sending a constant 'maximum voltage' signal to the ECU, like a stuck switch that won't turn off. This prevents the system from properly detecting whether someone is actually sitting in the driver's seat.

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Symptoms You May Notice
3 known symptoms for this code
Airbag warning light illuminated on dashboard
Seat belt reminder may not function correctly
Airbag system disabled or not deploying properly
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECU monitors the driver seat occupancy switch circuit voltage to determine if the seat is occupied. A short to battery causes the signal to remain at maximum voltage (12V) continuously, preventing the ECU from detecting normal seat presence changes. The module compares this input against expected voltage thresholds to validate circuit integrity.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Seat Occupancy Signal Voltage 0V to 5V (variable based on seat status) Constant 12V (shorted to battery)
Circuit Resistance Variable resistance 100-10k ohms Near 0 ohms (short condition)
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Wiring harness connector at seat occupancy switch
Inspect connector pins for corrosion, bent terminals, or water damage and reseat firmly.
2
Seat occupancy switch assembly
Unplug connector, test resistance with multimeter; replace switch if reading shows continuity to ground.
3
Driver seat occupancy sensor wiring
Trace wiring harness for pinched, torn, or abraded insulation contacting chassis ground.