Chassis, generic

C0905 TPMS Sensor 3 Battery Low

Check engine lightUsually off
EmissionsNot relevant
Drive cycleRequired
Limp modeNo

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.

Likely causes

Sensor cell near end of life (typically after many years)
Sensor stuck in a fast transmit mode, drawing the cell down early

Symptoms

  • TPMS lamp flashes about a minute after start, then stays on
  • Pressure values still shown, warning returns after every restart

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–200
Time0.5–1.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

tpms sensortpms receiver

Related codes

C0907C0900C0902C0952

References: saabwisonline.com, mitsubishitechinfo.com.