B0339Rear Seat Heater Circuit
- Generic OBD-II code · Body
- How the car detects it
- B0339 shows up neither in the public code lists nor in published service material. Rear seat heating is an option on larger cars; the GM-built 2011 Saab 9-4X with heated rear seats has a dedicated control module behind the rear backrest. It feeds both mats through a common supply, regulates by switching their ground with PWM and checks current and voltage every 10 s: B2425/B2430 0D mean element resistance too high, 0B/0E too much current or too little resistance. Each rear seat also carries an NTC sensor (B1925/B2170), and B2345 13 reports the shared disable line. US5229579A shows why such controllers shut off on a short or an open circuit.
- What you may notice
- One or both rear seat heaters stay cold
- Rear seat heating indicator flashes or goes out
- Likely causes
- LikelyHeating mat in a rear seat cushion broken
- PossibleConnector damaged when the rear seat was folded or removed
- PossibleRear seat heating control module or its supply faulty
- RareSeat temperature sensor implausible so heating is disabled
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.