A fault code doesn’t yet mean the unit or sensor itself is faulty: often it’s the plug and connector leading to it.
OOleg’s tip: it’s not always the sensor
It may not be the sensor itself but what it reads the signal from: the tone ring on the hub or axle shaft, or, on many cars, a magnetic ring that is built into the wheel bearing itself. Dirt, rust, a crack or damaged teeth, or bearing play — and there’s no signal even though the sensor is fine.
Remove the sensor and, turning the wheel slowly, look at the tone ring: are all the teeth intact and clean? Rock the wheel by hand — bearing play also disrupts the signal. The magnetic ring isn’t replaced separately: it’s part of the bearing.
Possible causes
- The sensor isn’t seated properly: too big a gap to the ring, or rust under the sensor
- This wheel’s speed sensor
- The tone ring or the bearing’s magnetic ring: a crack, dirt, stuck-on metal shavings, bearing play
What you can do yourself
- This code is stored in the sensor check mode (the scan tool’s test mode).
- Inspect this wheel’s sensor and its wire up to the connector: dirt, corroded pins, chafed insulation. Clean the connector, remove the sensor and clean its tip and its seat of dirt and rust.
- Check the tone ring or the bearing’s magnetic ring: cracks, damaged teeth, stuck-on metal shavings. Don’t clean a magnetic ring with a magnet.
Stop and don’t drive on if:
- The red brake light is on, or the brake pedal feels soft or sinks
- The steering became very heavy, or the car pulls to one side when braking
Find the part on Kaspi ShopBefore buying, check the part number or match the part by VIN in the Kaspi “Garage”.
On cars with flash-code self-diagnosis the ABS light shows this code as 73. This is the Toyota and Lexus meaning. On other makes this number means something else: if your car isn’t a Toyota or Lexus, change the make at the top.
Source: obdadvisor.com (C1271, C1272); Toyota ABS flash codes 71–74
The explanation comes from the error code reference in the AvtoElektrik PRO app.