ABS / traction light on: Codes, Causes & Fixes

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 P0500 Powertrain The engine computer lost its vehicle speed signal – speedometer, shifting and cruise control… Moderate P0501 Powertrain A speed signal exists, but it doesn't match what engine rpm, gear and other sensors say the car… Low

C1256 Toyota · Chassis The brake system's high-pressure accumulator is below its minimum, so power brake assist can't… Critical C1300 Toyota · Chassis The ABS/VSC computer failed its own internal self-test and has shut down ABS and stability… Moderate C1391 Toyota · Chassis The hybrid brake system is losing stored hydraulic pressure internally, so the pump keeps… High C1513 Kia · Chassis The stability control module thinks the brake light switch is lying about whether you're… Moderate 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 P0501 Powertrain A speed signal exists, but it doesn't match what engine rpm, gear and other sensors say the car… Low P0503 Powertrain The speed signal jumps, spikes or reads impossibly high – usually electrical noise or a loose… Low P0504 Powertrain The two contacts in the brake pedal switch disagree on whether you're braking; check the pedal… Moderate P0561 Powertrain System voltage jumps up and down instead of holding steady – often loose terminals… Low 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 P0571 Powertrain The engine computer doesn't trust the brake pedal switch signal – cruise control usually stops… Low 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 U0104 Network The adaptive cruise radar (or cruise module) went silent on the network, so cruise is switched… Low U0114 Network The module that engages the AWD coupling went silent; the car falls back to front… Low 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