Module Communication Trouble Codes: List & Fixes

U0073 Network A module saw so many errors on CAN bus A that it shut off its own transmitter. High U0100 Network Another module stopped hearing from the engine computer on the CAN network. High U0121 Network Other modules stopped receiving data from the ABS module, so ABS and stability control are off. Moderate

P1698 Jeep · Powertrain The engine computer stopped hearing from the transmission computer, often leaving the Jeep… 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 U0100 Network Another module stopped hearing from the engine computer on the CAN network. High U0101 Network The engine computer and other modules stopped hearing from the transmission control module. High U0102 Network Other modules can't hear the 4WD transfer case module, so 4WD shifting is disabled. Moderate U0103 Network The electronic shifter (dial, knob or joystick) stopped talking to the transmission and engine… High U0104 Network The adaptive cruise radar (or cruise module) went silent on the network, so cruise is switched… Low U0105 Network The PCM lost contact with the separate module that fires the injectors, common on diesel… High U0107 Network The engine computer can't reach the module that drives the electronic throttle, so power is cut… High U0109 Network The PCM lost contact with the module that controls fuel pump speed; stalling or no-start can… High U0110 Network The hybrid/EV system lost contact with the module that runs electric drive motor A. Critical U0114 Network The module that engages the AWD coupling went silent; the car falls back to front… Low U0115 Network Modules lost contact with the second engine computer on vehicles that use two of them. 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 U0131 Network The electric power steering module dropped off the network; steering assist may be reduced… High U0140 Network Other modules stopped hearing from the body control module that runs lights, locks, wipers… Moderate U0141 Network A body module labeled "A" went silent; on many trucks and SUVs it is the smart fuse box under… Moderate U0142 Network A secondary body module went silent; it often runs rear lights, liftgate, trailer and rear… Low U0146 Network The central gateway that links the car's networks went silent, so many modules report errors… Moderate U0151 Network Other modules can't reach the airbag computer, so the airbags and seatbelt pretensioners may… High U0155 Network Modules can't reach the instrument cluster, so gauges, warning lights and chimes may go dead. Moderate U0156 Network The main information display or head unit dropped off the network; screen, radio or camera may… Low U0164 Network The climate control module dropped off the network, so heat, A/C, fan or defrost may stop… Low U0199 Network The door module (usually the driver's door) went silent; windows, mirrors and locks on that… Low U0401 Network The engine computer is still on the network, but another module doesn't trust the numbers it's… Moderate U0402 Network The transmission module is online, but the gear, range or torque data it sends doesn't add up. Moderate