How severe is fault code C1947?

Serious — Stop or limit driving

OBD Code C1947: Seat Track Position Switch Circuit Short to Ground

Q: What does OBD code C1947 mean?

Seat Track Position Switch Circuit Short to Ground. The seat track position sensor is sending a constant ground signal to the ECU instead of varying signals, like a stuck light switch that's always off. This prevents the system from knowing where the seat is positioned.

Q: What are the symptoms of fault code C1947?

Seat position memory function not working, Warning light on dashboard related to seat adjustment, Seat track motor may not respond to adjustment commands

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What This Actually Means

In plain language — no jargon

The seat track position sensor is sending a constant ground signal to the ECU instead of varying signals, like a stuck light switch that's always off. This prevents the system from knowing where the seat is positioned.

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Symptoms You May Notice

3 known symptoms for this code

Seat position memory function not working

Warning light on dashboard related to seat adjustment

Seat track motor may not respond to adjustment commands

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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors the seat track position switch circuit for voltage changes as the seat moves. It expects a variable voltage signal between ground and battery voltage. When the circuit shorts to ground, the ECU detects continuous 0V instead of the expected signal variations, triggering the fault.

Voltage & Parameter Thresholds

Parameter	Normal Range	Fault Condition
Seat Position Signal Voltage	0.5V to 4.5V (variable with seat movement)	Constant 0V or below 0.1V
Signal Resistance	1kΩ to 100kΩ (varies with position)	Less than 50Ω (short to ground)

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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex

1

Wire harness connector

Inspect and reseat the seat track position switch connector at the seat base to eliminate corrosion or loose contact.

2

Wiring harness

Check the seat track wiring under the seat for cuts, abrasion, or pinches that expose conductors to the seat frame.

3

Seat track position switch

Replace the faulty switch if continuity testing confirms it's shorted to ground.

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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code C1947 is classified as a serious fault. If your check engine light is flashing — not just steady — pull over safely and do not continue driving. A flashing CEL indicates an active misfire or critical failure that can cause catalytic converter damage within minutes or permanent engine harm within miles. Contact a certified mechanic immediately. Do not attempt roadside repairs on high-severity codes unless you are trained to do so.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.

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How to Clear Code C1947

What happens after you fix the fault

Once the fault is repaired, C1947 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.

The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.

✅ Safe to Clear When

Fault has been diagnosed and repaired
You want to confirm the repair worked
Code appeared after a sensor was cleaned

⚠️ Do Not Clear When

Preparing for an emissions/PUC test
Root cause is still undiagnosed
Check engine light is flashing

Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.