What does it mean?
C1726 is a Chassis (ABS, traction control, steering) fault code. It indicates: Battery Voltage of RR Transmitter Drops. .
Symptoms
- Tyre pressure telltale flashing then staying on, showing a system fault
- No pressure value or an intermittent value for the right rear position
- Warning present even though all four tyres check out correctly with a gauge
- Symptom worse in winter and after the car has stood for a long time
- Relearn procedure fails or completes without the right rear reporting
Likely causes
- Normal end of life of the sealed cell in the right rear sensor
- Sensor stuck awake and transmitting continuously because of an internal circuit fault
- Long periods parked in extreme cold or extreme heat draining the cell faster
- Corrosion inside the sensor from moisture or tyre sealant
- Damage to the sensor stem or body during a previous tyre change
- Reused sensor from another vehicle with a partly exhausted battery
- Weak or intermittent radio signal from that corner interpreted as a low battery
How to fix it
- Read TPMS live data and note which sensors report and which do not
- Trigger all four sensors with a TPMS tool and compare their battery status
- Check that the ID stored for the right rear matches the sensor on that wheel, especially after a rotation
- Inspect the sensor, valve seal and the inside of the tyre for water or sealant when the tyre is removed
- Replace the right rear sensor, as the battery is sealed within the assembly
- Program the ID, perform the relearn and verify all four pressures appear
- Advise on the age of the other sensors so the customer can plan a set replacement