What does it mean?
C1502 is a Chassis (ABS, traction control, steering) fault code. It indicates: Tire Pressure Sensor 2 Internal .
Symptoms
- Tyre pressure warning lamp on and a service message on the display
- The second wheel position shows no reading or a stale value
- Pressure display does not change after adjusting that tyre
- System fails to complete a relearn because one sensor never answers
- No handling problem, the tyre holds air normally
Likely causes
- End of life internal battery in that sensor, typical after many years of service
- Physical damage to the sensor during tyre fitting or removal
- Broken or corroded valve stem, especially where an aluminium stem meets a steel nut
- Moisture inside the sensor housing after a damaged seal
- Sensor knocked out of position by a kerb or pothole impact
- Tyre sealant residue blocking the pressure port
- Incorrect or unprogrammed replacement sensor fitted to that wheel
How to fix it
- Read all sensor data with a TPMS tool, noting IDs, pressures and battery condition
- Activate each sensor at the wheel and identify the one that will not transmit
- Compare the displayed pressure with a manual gauge reading
- Confirm the sensor ID registered for that position matches the sensor on the wheel
- Inspect the valve stem, nut and seal for corrosion once the tyre is removed
- Fit a new sensor, program the ID and complete the position relearn
- Recheck all four or five positions and clear the stored code