Car won't start: Codes, Causes & Fixes

P0335 Powertrain The engine computer lost the crankshaft position signal. Expect stalling or a crank-no-start. High P0340 Powertrain The computer lost the camshaft signal on bank 1. Expect long cranking, less power… Moderate P0562 Powertrain The engine computer sees too little supply voltage – usually a charging, battery or ground… Moderate P0606 Powertrain The engine computer failed its own internal self-test – check its power and grounds before… Moderate 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

P1690 Hyundai · Powertrain The engine computer asked the SMARTRA immobilizer unit to check your key and got no answer back. Moderate P1693 Kia · Powertrain The immobilizer couldn't read a valid code from the chip in your Kia key, so the engine isn't… Moderate P1702 Ford · Powertrain Ford's gear selector position signal drops out now and then, so the PCM briefly loses track… Moderate P1E00 Chevrolet · Powertrain Volt/Bolt pointer code: the hybrid/EV controller found a fault and asked for the check engine… Moderate P204F Powertrain The DEF/SCR system isn't cutting NOx the way it should; ignored, it leads to a severe speed… Moderate P207F Powertrain The ECM thinks the DEF in the tank is too weak or contaminated, often right after a refill. Moderate P20E8 Powertrain The DEF pump can't build or hold enough pressure; suspect a leak, frozen line, clogged filter… Moderate P20EE Powertrain The SCR catalyst isn't removing enough NOx; DEF quality, dosing, a NOx sensor or the catalyst… Moderate P2105 Powertrain The engine computer shut the engine off on purpose because it could no longer control… Critical P2293 Powertrain The second fuel pressure control stage can't hold its target; on VW/Audi 2.0T often… Moderate P229F Powertrain The NOx sensor after the SCR catalyst is sending believable-looking but wrong or sluggish… Moderate P2502 Powertrain The ECM distrusts the charging system – no output, wrong voltage or an implausible alternator… Moderate P2503 Powertrain The alternator can't reach the voltage the ECM asks for – usually a worn alternator or slipping… Moderate P2BAC Powertrain EGR has been shut off because of a fault, so NOx is above the limit; fix the EGR code stored… Moderate P3000 Toyota · Powertrain Toyota's hybrid computer flags a fault in the high-voltage battery system and limits hybrid… High P3191 Toyota · Powertrain The hybrid system spun the gas engine with its motor-generator, but the engine never fired up. High 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 U0103 Network The electronic shifter (dial, knob or joystick) stopped talking to the transmission and engine… High U0105 Network The PCM lost contact with the separate module that fires the injectors, common on diesel… 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 U0115 Network Modules lost contact with the second engine computer on vehicles that use two of them. 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 U0146 Network The central gateway that links the car's networks went silent, so many modules report errors… Moderate U0404 Network The electronic shifter reports a lever position the transmission can't trust, so Park may not… High U0422 Network The body control module is sending data other modules reject, often after a BCM swap or wiring… Low U1000 Chevrolet · Network A module on an older GM's Class 2 data line couldn't communicate, so modules stopped hearing… Moderate