C0903 code meaning
TPMS Sensor 2 Position Performance
What C0903 means
Searches found C0903 neither in code lists nor in maker documents; a single NHTSA hit is a truck maker's campaign number. The title addresses locating transmitter 2 on the vehicle. Two methods are documented. A Ford patent puts a low frequency initiator into each wheel well: the controller fires it above about 20 mph, waits 3 seconds for the sensor to answer with its ID and a special status flag, raises the transmit power step by step and declares an error once the limit is reached without reply. A 2022 Mitsubishi system without initiators derives the position from the timing between the wheel speed sensors and each tire sensor. If either check ends without a clear match, the corner of sensor 2 stays unknown.
C0903 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.3 to 1.5 hours
- Clears after repairAfter a drive cycle
Symptoms of C0903
- TPMS lamp on with all tires correctly inflated
- Display shows pressures without assigning them to wheel positions
Common causes of C0903
- Most likelyLocation learning interrupted, e.g. short trips at low speed after tire service
- PossibleSensor does not answer the wheel well initiator (weak LF field, misaligned initiator)
- Less likelyAcceleration or rotation detection inside the sensor faulty
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 C0903 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 03 | The exact fault in that area. |
What to do next
- Note C0903 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 C0903
What does C0903 mean?
C0903 means "TPMS Sensor 2 Position Performance". Searches found C0903 neither in code lists nor in maker documents; a single NHTSA hit is a truck maker's campaign number. It is a generic code, so it means the same on every make.
Is it safe to drive with C0903?
C0903 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will C0903 fail an emissions test?
C0903 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 C0903 to fix?
Difficulty: medium. A typical repair takes 0.3 to 1.5 hours of work. This is a job for a workshop.
Will C0903 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.