OBD Code B1656: Seat Driver Rear Up Circuit Open

Q: What does OBD code B1656 mean?

Seat Driver Rear Up Circuit Open. The driver's rear seat up motor circuit has an open connection, meaning electricity can't flow to move the seat upward. It's like a broken light switch where the wire is cut and the light won't turn on.

💬

What This Actually Means

In plain language — no jargon

The driver's rear seat up motor circuit has an open connection, meaning electricity can't flow to move the seat upward. It's like a broken light switch where the wire is cut and the light won't turn on.

⚡

Symptoms You May Notice

3 known symptoms for this code

Driver rear seat up button doesn't respond or seat won't move upward

No clicking or motor sound when pressing the rear seat up control

Dashboard or seat control module warning light illuminated

🔬

How Your ECU Detects This

Technical sensor logic and voltage thresholds

The body control module monitors the driver's rear seat up motor circuit for proper voltage and current draw when the up command is activated. It detects an open circuit condition when expected current flow drops below threshold, indicating a broken wire, disconnected connector, or failed motor.

Voltage & Parameter Thresholds

Parameter	Normal Range	Fault Condition
Motor Circuit Current	2.5-8 amps during seat movement	Below 0.5 amps or no current detected
Circuit Voltage	12-14V when activated	0V or erratic voltage

🔧

Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex

1

Wiring connectors and terminals

Inspect and reseat all connectors at the seat motor and control module, cleaning corrosion from terminals.

2

Wiring harness

Check the entire circuit for pinched, cut, or damaged wires between the motor and body control module, repairing as needed.

3

Seat motor assembly

Test the motor with direct 12V power; if it doesn't respond, the motor is failed and requires replacement.

⚠️

When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code B1656 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.

🔄

How to Clear Code B1656

What happens after you fix the fault

Once the fault is repaired, B1656 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.