What does it mean?
C1725 is a Chassis (ABS, traction control, steering) fault code. It indicates: Battery Voltage of RF Transmitter Drops. .
Symptoms
- Tyre pressure lamp flashing at key on then remaining lit
- Right front pressure reading missing or dropping in and out in the display
- System reports a sensor fault while all tyres are correctly inflated
- Warning more likely in cold weather when battery output is weakest
- Fault persists through relearn attempts
Likely causes
- End of life of the sealed cell in the right front sensor, typically after several years of service
- Excessive transmission caused by an internal fault that stops the sensor going to sleep when parked
- Heat cycling from the front brake and long motorway runs shortening cell life
- Water ingress past the valve seal or sealant contamination damaging the circuit
- Sensor cracked or stressed by an incorrect tyre fitting procedure
- Second-hand sensor fitted with unknown remaining battery life
- Marginal signal strength at the receiver being logged as a battery fault
How to fix it
- Compare all four sensors' battery and signal status in TPMS live data
- Trigger the right front sensor with a TPMS tool; a completely dead sensor will not respond
- Verify that the ID registered to the right front position belongs to the fitted sensor
- Inspect the valve and sensor for corrosion, sealant contamination and damage when the tyre is dismounted
- Replace the sensor, since the internal cell cannot be serviced separately
- Program the new ID, run the relearn and confirm all positions report pressure
- Check the age of the remaining sensors and advise replacing the set if they date from the same period