C0905 code meaning
TPMS Sensor 3 Battery Low
What C0905 means
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.
C0905 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 1.5 hours
- Clears after repairAfter a drive cycle
Symptoms of C0905
- TPMS lamp flashes about a minute after start, then stays on
- Pressure values still shown, warning returns after every restart
Common causes of C0905
- Most likelySensor cell near end of life (typically after many years)
- Less likelySensor stuck in a fast transmit mode, drawing the cell down early
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Tpms sensorTpms receiver
What each part of C0905 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 05 | The exact fault in that area. |
What to do next
- Note C0905 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about C0905
What does C0905 mean?
C0905 means "TPMS Sensor 3 Battery Low". No manufacturer is known to use C0905; none of the code lists, service indexes or NHTSA bulletins searched contains it. It is a generic code, so it means the same on every make.
Is it safe to drive with C0905?
C0905 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will C0905 fail an emissions test?
C0905 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is C0905 to fix?
Difficulty: medium. A typical repair takes 0.5 to 1.5 hours of work. This is a job for a workshop.
Will C0905 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.