OBD Code B1950: Seat Rear Up/Down Potentiometer Feedback Circuit Failure

Q: What does OBD code B1950 mean?

Seat Rear Up/Down Potentiometer Feedback Circuit Failure. The car's computer can't read the feedback signal from the rear seat up/down position sensor, similar to a volume knob that won't report back to your stereo about where it's set. This prevents the seat from adjusting properly or the system from knowing its actual position.

Q: What are the symptoms of fault code B1950?

Rear seat up/down button unresponsive or not functioning, Seat moves but control module cannot verify position, Dashboard warning light or comfort system malfunction indicator

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What This Actually Means

In plain language — no jargon

The car's computer can't read the feedback signal from the rear seat up/down position sensor, similar to a volume knob that won't report back to your stereo about where it's set. This prevents the seat from adjusting properly or the system from knowing its actual position.

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Symptoms You May Notice

3 known symptoms for this code

Rear seat up/down button unresponsive or not functioning

Seat moves but control module cannot verify position

Dashboard warning light or comfort system malfunction indicator

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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors the potentiometer voltage output from the rear seat motor position sensor as it moves up and down. It expects a smooth analog voltage sweep corresponding to seat travel. If voltage remains static, spikes outside expected range, or becomes unreadable, the ECU flags a feedback circuit failure.

Voltage & Parameter Thresholds

Parameter	Normal Range	Fault Condition
Potentiometer Voltage	0.5V to 4.5V (proportional to seat position)	Below 0.1V, above 4.9V, or no change during motor operation
Voltage Rate of Change	Gradual sweep during seat actuation	No voltage change when motor commanded, or erratic jumps

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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex

1

Potentiometer connector and wiring harness

Inspect and reseat the connector at the rear seat motor assembly; clean corroded pins with electrical contact cleaner.

2

Potentiometer sensor

Replace the faulty position sensor if connector cleaning does not resolve the code.

3

Wiring harness section

Repair or splice damaged wiring between the potentiometer and seat control module if corrosion or physical damage is found.

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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code B1950 is a low-severity fault. Your vehicle is generally safe to drive to a workshop for diagnosis. However, do not ignore it indefinitely — low-severity codes often indicate developing problems that become expensive if neglected. Book a diagnostic appointment within 2–4 weeks. If you notice any additional symptoms (rough running, power loss, unusual smells), treat it as higher priority.

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 B1950

What happens after you fix the fault

Once the fault is repaired, B1950 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.