OBD Code B1704: Seat Driver Recline Forward Switch Circuit Short To Ground

Q: What does OBD code B1704 mean?

Seat Driver Recline Forward Switch Circuit Short To Ground. The seat's recline forward switch is sending a constant ground signal to the ECU, like a light switch stuck in the 'on' position. This electrical short prevents the seat control system from properly detecting when you want to adjust the seat recline.

Q: How do I fix OBD fault code B1704?

Inspect connector at seat base for moisture, corrosion, or loose pins; clean with electrical contact cleaner and reseat firmly.. Test switch continuity with multimeter; replace if stuck or showing zero resistance in rest state.. Inspect entire circuit from switch to seat module for damaged insulation, chafing, or pinched wires causing ground contact.

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What This Actually Means

In plain language — no jargon

The seat's recline forward switch is sending a constant ground signal to the ECU, like a light switch stuck in the 'on' position. This electrical short prevents the seat control system from properly detecting when you want to adjust the seat recline.

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Symptoms You May Notice

3 known symptoms for this code

Seat recline control not responding or stuck in one position

Seat adjustment warning light or message on dashboard

Inability to manually recline driver seat forward

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Embedded Systems Insight

What the ECU/ECM is actually computing

The ECU monitors the voltage signal from the driver seat recline forward switch. Under normal operation, the switch should toggle between high and low voltage when pressed. A short to ground forces the signal to remain at 0V continuously, indicating a persistent fault condition that the ECU detects as abnormal circuit resistance.

Voltage & Parameter Thresholds

Parameter	Normal Range	Fault Condition
Switch Signal Voltage	5V (unpressed) to 0V (pressed) with proper resistance	Continuous 0V or <0.5V indicating short to ground
Circuit Resistance	>10kΩ open, <100Ω closed	<1Ω indicating direct short path

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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex

1

Wiring harness connector

Inspect connector at seat base for moisture, corrosion, or loose pins; clean with electrical contact cleaner and reseat firmly.

2

Driver seat recline switch

Test switch continuity with multimeter; replace if stuck or showing zero resistance in rest state.

3

Wiring harness

Inspect entire circuit from switch to seat module for damaged insulation, chafing, or pinched wires causing ground contact.