B1728
Seat Driver Rear Up Switch Circuit Short To Ground
Body Chassis/Safety Seat Controls 🟢 Low — Fix at next service
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What This Actually Means
In plain language — no jargon

The driver's rear seat up switch is electrically shorted to ground, preventing the seat control module from detecting when the switch is pressed. It's like a light switch that's permanently stuck in the 'on' position due to damaged wiring.

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Symptoms You May Notice
3 known symptoms for this code
Driver rear seat up function does not work
Seat control warning light illuminated on dashboard
Unable to adjust rear seat position upward
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECU monitors voltage on the seat up switch circuit, expecting high voltage when the switch is open and low voltage when activated. A short to ground causes the circuit to remain at 0V continuously, which the module interprets as a permanent fault condition rather than a valid switch input.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Switch Circuit Voltage 12V (open) / 0-2V (activated) Constant 0V or short to ground detected
Circuit Resistance Greater than 10 kOhms open Less than 1 kOhm to ground
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Seat switch connector and wiring harness
Inspect the switch connector under the driver's seat for corrosion, loose pins, or damaged insulation and reseat or replace as needed.
2
Driver rear seat up switch
Test switch continuity with a multimeter; if shorted internally, replace the switch assembly.
3
Seat wiring harness
Check the wiring between seat and module for chafing or pinched areas causing short to ground and repair or replace damaged sections.