OBD Code B1658: Seat Driver Rear Up Circuit Short To Ground

Q: What does OBD code B1658 mean?

Seat Driver Rear Up Circuit Short To Ground. The driver's rear seat cushion up motor circuit is shorted to ground, meaning electricity is taking an unintended path to ground instead of flowing properly through the motor. Think of it like a water pipe that has a hole in it—the water leaks out before reaching its destination.

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What This Actually Means

In plain language — no jargon

The driver's rear seat cushion up motor circuit is shorted to ground, meaning electricity is taking an unintended path to ground instead of flowing properly through the motor. Think of it like a water pipe that has a hole in it—the water leaks out before reaching its destination.

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Symptoms You May Notice

3 known symptoms for this code

Driver rear seat up button does not work or seat moves erratically

Seat control module warning light illuminates on dashboard

Inability to adjust rear seat cushion height upward

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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors voltage and current flowing through the driver rear seat up motor circuit. It expects a specific voltage drop across the motor when activated; a short to ground causes abnormally high current draw and near-zero voltage at the motor, triggering the fault.

Voltage & Parameter Thresholds

Parameter	Normal Range	Fault Condition
Motor Circuit Voltage	10-14V when activated	<2V (short to ground detected)
Circuit Current Draw	2-8 amps during movement	>15 amps or out-of-range spike

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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex

1

Seat wiring harness connector

Inspect and reseat the connector at the seat motor; corrosion or loose terminals often cause false shorts.

2

Seat motor wiring and insulation

Check for damaged wire insulation, pinched cables, or exposed copper touching the seat frame and repair or replace the affected section.

3

Seat up motor assembly

Replace the motor if it has an internal short or if wiring replacement does not resolve the code.

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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code B1658 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 B1658

What happens after you fix the fault

Once the fault is repaired, B1658 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.