ABS / traction light on: Codes, Causes & Fixes

When the ABS or traction control light is on, the anti-lock and stability functions are usually disabled while normal braking still works – so allow extra stopping distance, especially on wet or icy roads. The most frequent causes are a wheel speed sensor, its wiring or a dirty or cracked tone ring, followed by low brake fluid and ABS module faults. If the red brake warning light is on as well, or the pedal feels soft, stop driving and have the brakes checked.

65Codes

3.0Average severity

12%High or critical

15%DIY-friendly

Severity distribution

Most viewed

C0035 Chassis The ABS module lost a valid signal from the driver-side front wheel speed sensor. Moderate P0562 Powertrain The engine computer sees too little supply voltage – usually a charging, battery or ground… Moderate U0073 Network A module saw so many errors on CAN bus A that it shut off its own transmitter. High U0121 Network Other modules stopped receiving data from the ABS module, so ABS and stability control are off. Moderate U0122 Network Other modules lost contact with the stability control computer, so ESC and traction control… Moderate P0500 Powertrain The engine computer lost its vehicle speed signal – speedometer, shifting and cruise control… Moderate

All codes (55)

All Severity 3+ Severity 4+

C1611 Hyundai · Chassis The ABS/ESC module stopped hearing from the engine computer on the CAN bus and shut off… Moderate C2200 Jeep · Chassis The ABS module found a fault in its own electronics and shut off ABS, traction and stability… Moderate P0500 Powertrain The engine computer lost its vehicle speed signal – speedometer, shifting and cruise control… Moderate P0504 Powertrain The two contacts in the brake pedal switch disagree on whether you're braking; check the pedal… Moderate P0562 Powertrain The engine computer sees too little supply voltage – usually a charging, battery or ground… Moderate P0563 Powertrain The engine computer sees too much supply voltage – usually an overcharging alternator cooking… Moderate P0572 Powertrain The PCM never sees the brake pedal pressed – brake lights may be out and the car may not shift… Moderate P1380 Chevrolet · Powertrain A misfire was detected, and the ABS module couldn't supply rough-road data to confirm it wasn't… Moderate P1381 Chevrolet · Powertrain A misfire was detected while the PCM had lost contact with the ABS module that supplies… Moderate P2504 Powertrain The charging system is overcharging – too much voltage can boil the battery and damage… High P25A2 Chevrolet · Powertrain The brake module stored a fault and asked the engine computer to turn on the check engine light. Moderate U0001 Network A module found the high-speed CAN network itself misbehaving, not just one silent module. High U0073 Network A module saw so many errors on CAN bus A that it shut off its own transmitter. High U0121 Network Other modules stopped receiving data from the ABS module, so ABS and stability control are off. Moderate U0122 Network Other modules lost contact with the stability control computer, so ESC and traction control… Moderate U0126 Network Modules no longer receive the steering wheel angle, so stability control and lane assist switch… Moderate U0128 Network The electronic parking brake module dropped off the network, so the parking brake may not apply… Moderate U0146 Network The central gateway that links the car's networks went silent, so many modules report errors… Moderate U0401 Network The engine computer is still on the network, but another module doesn't trust the numbers it's… Moderate U0415 Network The ABS module is online, but the wheel-speed data it shares looks wrong to the other modules. Moderate U0416 Network Stability-control data (steering angle, yaw rate) failed a plausibility check in another module. Moderate U0418 Network Brake-control data such as pedal position or brake-assist status looks implausible to another… High U0420 Network The electric power steering module is talking, but its steering angle or torque data doesn't… Moderate U1000 Nissan · Network A Nissan control module couldn't send or receive CAN messages for about 2 seconds or longer. Moderate U1900 Ford · Network A Ford module stopped receiving messages it expects from another module on the CAN network. Moderate

Symptoms

Check engine light on 558 Loss of power 214 Rough idle 184 Limp mode 165 Poor fuel economy 146 Engine stalling 133 Car won't start 123 Harsh or slipping shifts 80 Fuel smell 34 Check engine light flashing 22