0X9309E8: Driver Seat Position Sensor

Circuit fault

What 0X9309E8 means

A seat position sensor reports whether the seat is forward or rearward on its track. The ACSM factors that into deployment strategy, because a driver sitting close to the wheel needs a gentler first stage than a driver sitting back. The sensor is usually a Hall effect device or a reed switch mounted on the seat rail, and when its circuit reads open the module logs 0X9309E8.

Position sensors sit low on the rail in a spot that collects everything dropped in the car. They also depend on a magnet or target that has to stay aligned with the sensor as the seat travels. A sensor knocked out of position by a foot or by cargo reads the same as a broken wire once the module stops getting a usable signal from it.

Common causes

• A broken or pulled wire in the seat rail harness where it flexes with seat travel
• The sensor knocked loose from its bracket or the target magnet bent out of alignment
• A connector unlatched or damaged during seat removal or floor work
• Corrosion at the sensor connector from wet carpet
• Debris packed around the sensor blocking the target
• A failed sensor element that no longer switches

Crash data or hardware fault?

Live faults are what this category is about, and 0X9309E8 is one of them. The module reads the sensor circuit continuously and reports an open when it finds one, then drops the entry once continuity returns. Crash data belongs to a separate part of memory, written at deployment, and it is permanent regardless of what any sensor circuit is doing.

Does our reset clear it?

Clearing the module does not reconnect an open circuit. Repair the wiring or replace the sensor, then erase the code normally. Our mail-in reset service is aimed at modules that are locked by stored deployment data, which is a different problem than a seat sensor. Call 501-988-0611 if you are not sure which of the two you are dealing with and we will help sort it out.

Which makes throw it

0X9309E8 is read on BMW vehicles through BMW hex diagnostics. Other manufacturers monitor a driver seat position sensor as well, but they assign their own code numbers to it.

What to do next

Run the seat all the way forward and all the way back while watching live data, because a sensor that changes state at neither end is either disconnected or misaligned. Look under the seat for the sensor and its target and confirm both are still where they belong. If the wiring is broken at the rail, repair it properly rather than splicing loosely, since it will keep moving for the life of the car. Related codes: 0X9309C4, 0X9309FB, B1B08.