OBD-II Trouble Codes: Meaning & Fixes

P0174 Powertrain The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction… Moderate P0420 Powertrain The bank 1 catalytic converter no longer stores enough oxygen to clean the exhaust properly. Low B0001 Body The airbag module found a fault in the firing circuit for the driver's front airbag (stage 1). High C0035 Chassis The ABS module lost a valid signal from the driver-side front wheel speed sensor. Moderate P0101 Powertrain The MAF sensor's airflow reading doesn't match what the engine computer expects… Low P0113 Powertrain The intake air temperature signal is stuck at maximum voltage, which usually means an open… Low

P1614 Nissan · Powertrain The Nissan immobilizer couldn't read the transponder chip in the key, so the engine isn't… Moderate P1626 Chevrolet · Powertrain The engine computer lost the 'OK to fuel' signal from the Chevy anti-theft system, so it may… Moderate P1631 Chevrolet · Powertrain The engine computer received the wrong anti-theft password, so it blocks starting or fuel. Moderate P1633 Ford · Powertrain Ford's PCM lost its constant battery feed, so the memory holding learned fuel, idle and shift… Low P1656 Toyota · Powertrain Toyota's ECM has found an open or short in the electrical circuit of the VVT-i oil control… Low P1682 Chevrolet · Powertrain The engine computer's two ignition power feeds disagree, which can cause stalling or Reduced… High P1684 Jeep · Powertrain An informational code: your Jeep's PCM lost battery power at some point in the last 50 engine… Minor 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 P1698 Jeep · Powertrain The engine computer stopped hearing from the transmission computer, often leaving the Jeep… Moderate P1702 Ford · Powertrain Ford's gear selector position signal drops out now and then, so the PCM briefly loses track… Moderate P1735 Volkswagen · Powertrain The DSG control unit lost a valid signal from the sensor that tracks clutch 1 and locks out… High P175D Volkswagen · Powertrain The DSG computer saw clutch 1 let go while it was supposed to stay engaged, so it cut… High P1778 Nissan · Powertrain The Jatco CVT's step motor is being commanded, but the pulley ratio isn't following it as it… High P17F0 Nissan · Powertrain The TCM detected judder it blames on the CVT itself, usually belt or pulley slip inside… High P17F1 Nissan · Powertrain The TCM caught a judder event it links to the CVT's control valve (valve body), not yet to belt… Moderate P1E00 Chevrolet · Powertrain Volt/Bolt pointer code: the hybrid/EV controller found a fault and asked for the check engine… Moderate P2002 Powertrain The ECU thinks the diesel particulate filter isn't trapping soot properly — or it can't measure… Moderate P2004 Powertrain The intake runner or tumble flaps stay open when told to close, usually a vacuum or linkage… Low P2006 Powertrain The intake swirl or runner flaps stay shut when the ECU wants them open, choking airflow… Moderate P2009 Powertrain The runner or tumble flap solenoid circuit reads too low: a short to ground, an open coil… Low P200A Powertrain The ECU switched the intake runner flaps but the system didn't respond the way it should. Low P2015 Powertrain The sensor on the intake manifold flaps reports a position that doesn't match what the ECU… Low 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 P2096 Powertrain The sensor behind the catalytic converter keeps reporting lean, and the ECU has run out of room… Low P2097 Powertrain The sensor behind the converter keeps seeing rich exhaust, and the ECU can't lean the mixture… Low 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 P2100 Powertrain The computer can't push current through the throttle motor – the circuit to the throttle body… High