Seat Driver Front Up Switch Circuit Failure
The seat's up switch circuit isn't communicating properly with the control module, like a broken button that doesn't send its signal when pressed. The ECU can't detect when you're trying to move the seat upward.
The ECU monitors the voltage signal from the driver seat up switch circuit. When the switch is pressed, it should toggle a signal from high to low voltage. If the ECU detects an open circuit, short circuit, or voltage outside expected range, it logs the fault.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Switch signal voltage | 12V when inactive, 0V when activated | Stuck voltage, no transition, or signal loss |
| Circuit resistance | Below 1 ohm when closed | Above 5 ohms or infinite resistance (open circuit) |
Code B1709 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.
Once the fault is repaired, B1709 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.