C0905TPMS Sensor 3 Battery Low
- Generic OBD-II code · Chassis
- Needs a drive cycle to confirm a fix
- How the car detects it
- No manufacturer is known to use C0905; none of the code lists, service indexes or NHTSA bulletins searched contains it. The title names a weak battery in the third wheel transmitter. GM and Saab file this condition by wheel rather than by number, as subcode 03 Low Voltage under C0750 to C0765; on the 2011 Saab 9-5 the check needs more than 40 km/h, when a centrifugal roll switch puts each sensor into rolling mode and the door lock receiver forwards its data to the body module. Mitsubishi's counterpart for tire 3 is C1930, raised when the reception warning stems from low transmitter voltage. A low battery alone leaves pressures readable at first, so this is an early warning; the sensor will soon need replacing.
- What you may notice
- TPMS lamp flashes about a minute after start, then stays on
- Pressure values still shown, warning returns after every restart
- Likely causes
- LikelySensor cell near end of life (typically after many years)
- RareSensor stuck in a fast transmit mode, drawing the cell down early
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.