OBD-II and manufacturer-specific diagnostic trouble codes for cars and trucks across all major manufacturers.
178 error codes
178 codes
P0A0F means on a hybrid, the engine failed to start when the hybrid system commanded it — the petrol engine did not fire as expected.
P0A80 means the hybrid battery pack has degraded to the point the system requests replacement — one or more cell blocks are weak or imbalanced.
P0AA6 means the hybrid/EV system detected a loss of isolation between the high-voltage battery and the chassis — a potential high-voltage safety fault.
P0010 means a fault in the camshaft variable valve timing (VVT) actuator "A" circuit on bank 1 — the oil-control solenoid that adjusts cam timing.
P0011 means the camshaft (variable valve timing) on bank 1 is over-advanced or the system isn’t responding correctly.
P0014 means the exhaust camshaft timing on bank 1 is over-advanced — the cam is more advanced than the ECM commanded.
P0016 means the crankshaft and camshaft position signals are out of sync — they don’t correlate as the ECM expects.
P0068 means the ECM sees a mismatch between the air-flow (MAF/MAP) reading and the throttle position — the airflow doesn't match how far the throttle is open.
P0069 means the ECM sees a mismatch between the manifold pressure (MAP) and barometric pressure readings — the two pressure signals disagree.
P0071 means the ambient (outside) air temperature sensor reading is out of its expected range — the sensor used for climate control and some fuel calculations.
P0087 means the fuel pressure in the rail/system is lower than the ECM commands.
P0088 means the fuel rail pressure is higher than the ECM commands — the high-pressure fuel system is over-pressurised.
P0090 means a fault in the fuel pressure regulator control circuit — the ECM cannot correctly control fuel pressure (common on direct-injection/diesel systems).
P0100 means a malfunction in the mass air flow (MAF) sensor circuit — the sensor that measures how much air enters the engine so the ECM can meter fuel.
P0101 means the mass air flow sensor’s signal is outside the expected range for engine conditions.
P0102 means the mass air flow (MAF) sensor signal is lower than expected — the ECM is reading less airflow than the engine is actually drawing.
P0103 means the mass air flow (MAF) sensor signal is higher than expected — the ECM is reading more airflow than is plausible.
P0106 means the manifold absolute pressure (MAP) sensor is reading outside its normal range — the sensor that measures intake vacuum/pressure for fuelling and timing.
P0107 means the manifold absolute pressure (MAP) sensor signal is too low — often read as very high vacuum or an open circuit.
P0108 means the manifold absolute pressure (MAP) sensor signal is too high — often read as low vacuum or a shorted circuit.
P0112 means the intake air temperature (IAT) sensor signal is too low — the ECM reads an implausibly high intake temperature.
P0113 means the intake air temperature sensor is reporting an abnormally high (or open-circuit) signal.
P0116 means the coolant temperature sensor’s reading is implausible or doesn’t change as expected.
P0117 means the engine coolant temperature (ECT) sensor signal is too low — the ECM reads an implausibly high temperature.
P0118 means the engine coolant temperature (ECT) sensor signal is too high — the ECM reads an implausibly cold temperature.
P0120 means a malfunction in the throttle/pedal position sensor "A" circuit — the primary sensor telling the ECM the throttle opening.
P0121 means the throttle position sensor signal doesn’t match expected values or the other throttle inputs.
P0122 means the throttle position sensor (TPS) signal is too low — the ECM cannot read how far the throttle is open.
P0123 means the throttle position sensor (TPS) signal is too high — an implausible wide-open reading.
P0125 means the engine is not reaching the temperature needed for closed-loop fuel control within the expected time.
P0128 means the engine isn’t reaching normal operating temperature in the expected time — usually a thermostat stuck open.
P0130 means a malfunction in the upstream oxygen sensor circuit (bank 1, sensor 1) — the main sensor the ECM uses to trim the air/fuel mixture.
P0131 means the upstream oxygen sensor on bank 1 is reading persistently low (lean) voltage.
P0132 means the upstream oxygen sensor (bank 1, sensor 1) is reporting a persistently high voltage — a rich reading or a shorted signal.
P0133 means the upstream oxygen (O2) sensor (bank 1, sensor 1) is responding too slowly to changes in the exhaust mixture.
P0134 means the upstream oxygen (O2) sensor (bank 1, sensor 1) is inactive — the ECM sees no varying signal from it.
P0135 means the heater circuit inside the upstream O2 sensor (bank 1) is faulty.
P0136 means a malfunction in the downstream oxygen sensor circuit (bank 1, sensor 2) — the post-catalyst sensor used to monitor converter efficiency.
P0138 means the downstream oxygen sensor (bank 1, sensor 2) is reporting a persistently high voltage — an unusually rich reading after the converter.
P0139 means the downstream oxygen sensor (bank 1, sensor 2) is responding too slowly — the post-catalyst monitor is sluggish.
P0140 means the downstream oxygen sensor (bank 1, sensor 2) shows no activity — the ECM sees a flat, unresponsive signal.
P0141 means a fault in the heater circuit of the downstream oxygen sensor (bank 1, sensor 2) — the heater that brings the sensor to operating temperature.
P0150 means a malfunction in the upstream oxygen sensor circuit on bank 2, sensor 1 (the second cylinder bank on V-engines).
P0155 means a fault in the heater circuit of the upstream oxygen sensor on bank 2, sensor 1.
P0161 means a fault in the heater circuit of the downstream oxygen sensor on bank 2, sensor 2 (the second cylinder bank on V-engines).
P0170 means the fuel trim on bank 1 has drifted beyond its correction limits — the ECM can no longer keep the mixture correct.
On a Toyota Camry, P0171 means the engine computer has found the Bank 1 air-fuel mixture running too lean — more air than the fuel system can compensate for — after fuel trims maxed out trying to correct it.
P0172 means the engine on bank 1 is running rich — too much fuel or too little air — beyond what the ECM can trim out.
P0174 means the engine on bank 2 is running lean — the same lean condition as P0171 but on the other cylinder bank.
P0175 means bank 2 is running too rich — the ECM is pulling fuel out but the mixture is still over-fuelled.
P0182 means the fuel temperature sensor "A" signal is too low — the sensor used (mainly on diesels/flex-fuel) to adjust fuelling for fuel density.
P0191 means the fuel rail pressure sensor is reading out of its expected range — critical on direct-injection and diesel high-pressure fuel systems.
P0217 means the engine has exceeded its safe coolant temperature — the ECM has recorded an overheat condition.
P0221 means the second throttle position sensor (TPS "B") is out of its expected range — used on electronic throttle bodies as a redundant signal.
P0230 means a fault in the fuel pump primary (control) circuit — the relay/driver circuit that powers the fuel pump.
P0234 means the turbocharger or supercharger is producing more boost pressure than the ECM commands (overboost).
P0299 means the turbocharger or supercharger is producing less boost than the ECM commands (underboost).
The engine control module has detected misfires across multiple cylinders.
P0315 means the crankshaft position system variation has not been learned — the ECM needs this relearn to accurately detect misfires.
P0316 means the ECM detected a misfire during the first seconds after starting — an early misfire before the engine settles.
P0320 means a fault in the ignition/distributor engine speed (RPM) input circuit — the ECM isn't getting a reliable engine-speed signal.
P0325 means a fault in the knock (detonation) sensor circuit on bank 1 — the sensor that lets the ECM retard timing to prevent knock.
P0326 means the knock sensor signal on bank 1 is out of its expected range — the sensor that detects detonation so the ECM can retard timing.
P0327 means the knock sensor circuit (bank 1) signal is too low — the sensor that detects engine detonation so the ECM can retard timing.
P0335 means a fault in the crankshaft position sensor circuit — the sensor that tells the ECM engine speed and position.
P0336 means the crankshaft position (CKP) sensor signal is out of range — the sensor that reports engine speed and position for spark and injection.
P0340 means a fault in the camshaft position sensor circuit — the sensor the ECM uses to identify cylinder timing.
P0341 means the camshaft position (CMP) sensor signal is out of range or out of sync with the crankshaft — used for injection/ignition timing and cam control.
P0344 means the camshaft position sensor "A" (bank 1) signal is intermittent — it drops out occasionally.
P0350 means a general fault in the ignition coil primary/secondary circuit — the ECM detected a coil circuit problem.
P0400 means a general fault in exhaust gas recirculation (EGR) flow — the EGR system isn't flowing correctly.
P0401 means the EGR system isn’t flowing enough exhaust gas back into the intake, usually from carbon blockage.
P0402 means exhaust gas recirculation (EGR) flow is excessive — too much exhaust is being recirculated.
P0403 means an electrical fault in the exhaust gas recirculation (EGR) control circuit — the ECM cannot properly command the EGR valve.
P0404 means the exhaust gas recirculation (EGR) position/feedback is out of range — the valve isn't reporting the expected position.
P0410 means a malfunction in the secondary air injection system — the pump that adds air to the exhaust on cold start to cut emissions.
P0411 means the secondary air injection system is delivering incorrect airflow — the system that pumps air into the exhaust on cold start to reduce emissions.
The catalytic converter on bank 1 is not operating as efficiently as expected.
P0421 means the warm-up catalytic converter efficiency on bank 1 is below threshold — the converter is not cleaning the exhaust well enough during warm-up.
P0422 means the main catalytic converter efficiency on bank 1 is below threshold — the converter isn't cleaning the exhaust well enough.
P0430 means the catalytic converter on bank 2 isn’t cleaning the exhaust efficiently — the same fault as P0420 but on the other bank.
P0431 means the warm-up catalytic converter efficiency on bank 2 is below threshold (the bank not containing cylinder 1 on V-engines).
P0432 means the main catalytic converter efficiency on bank 2 is below threshold — the converter on the second bank isn't cleaning exhaust well enough.
P0440 means a general fault in the evaporative emissions (EVAP) system — fuel vapour is not being contained or purged correctly.
P0441 means the evaporative emissions (EVAP) system purge flow is incorrect — fuel vapour is not being drawn into the engine as expected.
P0442 means the evaporative-emissions system has a small leak that lets fuel vapour escape.
P0443 means an electrical fault in the evaporative emissions (EVAP) purge control valve circuit — the valve that lets stored fuel vapour into the intake.
P0446 means a fault in the EVAP vent valve/control circuit — the valve that lets the charcoal canister breathe.
P0447 means the evaporative emissions (EVAP) vent control circuit is open — the vent valve isn't responding, so leak tests can't run.
P0449 means an electrical fault in the evaporative emissions (EVAP) vent valve/solenoid circuit — the valve that seals the charcoal canister for leak tests.
P0452 means the evaporative emissions (EVAP) pressure sensor signal is too low — the sensor used to run fuel-system leak tests.
P0455 means the evaporative-emissions system has a large leak — a significant vapour escape.
P0456 means the evaporative emissions (EVAP) system has a very small leak — vapour is escaping through a tiny gap.
P0457 means the evaporative emissions (EVAP) system detected a leak traced to the fuel cap — usually loose, missing, or a bad seal.
P0462 means the fuel level sensor signal is too low — the ECM reads an implausibly low fuel level.
P0480 means a fault in the cooling fan control circuit (fan 1) — the ECM/relay that switches the radiator fan.
P0483 means the cooling fan system failed a rationality (performance) check — the fan isn't behaving as the ECM expects.
P0496 means the evaporative emissions (EVAP) system is showing high purge flow — vapour is being drawn in when it should not be, often a stuck-open purge valve.
P0500 means the ECM isn’t receiving a valid vehicle speed signal.
P0501 means the vehicle speed sensor (VSS) signal is out of its expected range — the sensor that reports road speed to the ECM and speedometer.
P0505 means a fault in the idle air control system — the ECM can’t maintain the target idle speed.
P0506 means the engine is idling lower than the ECM’s target.
P0507 means the engine is idling higher than the ECM’s target.
P0508 means the idle air control (IAC) circuit signal is too low — the valve that meters idle air isn't being controlled correctly.
P0513 means the immobilizer (anti-theft) system does not recognise the key — the transponder signal is missing or incorrect.
P0521 means the oil pressure sensor is sending an implausible signal — it doesn’t match expected oil pressure.
P0522 means the engine oil pressure sensor is reporting a low signal/voltage — which may indicate low oil pressure or a sensor/wiring fault.
P0523 means the engine oil pressure sensor is reporting an implausibly high signal/voltage.
P0562 means the electrical system voltage is lower than the ECM expects — a charging or battery problem.
P0563 means the ECM has detected a higher-than-normal system (battery) voltage — usually a charging-system problem.
P0571 means a fault in the brake switch "A" circuit — the switch that tells modules when the brake pedal is pressed.
P0600 means a fault in the serial communication link between control modules — the network (often CAN bus) modules use to talk to each other.
P0601 means the ECM/PCM has failed its internal memory (checksum) self-test — an internal fault in the control module.
P0603 means the ECM/PCM keep-alive memory (KAM) has failed or been lost — the module's stored adaptive learning was corrupted or reset.
P0604 means the ECM/PCM failed an internal RAM (random-access memory) self-test — an internal fault in the control module.
P0605 means the ECM/PCM failed an internal ROM (read-only memory) self-test — corrupted program memory in the control module.
P0606 means an internal processor fault in the ECM/PCM — the module has detected a problem with its own processor.
P0607 means the ECM/PCM has detected an internal performance fault — the module isn't operating within its own expected parameters.
P0620 means a fault in the generator (alternator) control circuit — the ECM cannot properly control charging output.
P0625 means a fault at the generator (alternator) field terminal circuit — the field/regulator control connection is faulty.
P0627 means a fault in the fuel pump control circuit — the ECM/relay/driver that commands the fuel pump.
P0630 means the vehicle identification number (VIN) is missing or mismatched in the ECM/PCM — usually after a module was replaced/reflashed without programming the VIN.
P0638 means the throttle actuator control on bank 1 is out of range — the electronic throttle isn't reaching its commanded position.
P0642 means the ECM's sensor reference voltage "A" (typically the 5V supply shared by several sensors) is too low — often a short pulling the reference down.
P0645 means a fault in the air-conditioning compressor clutch relay control circuit — the ECM can't reliably engage the A/C clutch.
P0650 means a fault in the malfunction indicator lamp (MIL / check engine light) control circuit — the ECM can't control the warning light correctly.
P0685 means a fault in the ECM/PCM power relay control circuit — the main relay that supplies power to the engine computer.
P0700 means the transmission control module has detected a fault and is asking the ECM to turn on the check engine light — it points you to look for a stored transmission code.
P0703 means a fault in the brake switch "B" circuit — a brake-signal input used by the transmission/torque-converter and cruise control.
P0705 means a fault in the transmission range sensor (PRNDL / neutral safety switch) circuit — the sensor that tells the ECM which gear position is selected.
P0706 means the transmission range sensor (gear-position switch) signal is out of range/performance — the ECM can't confirm the selected gear.
P0710 means a fault in the transmission fluid temperature (TFT) sensor circuit — used to protect the transmission and adapt shifts.
P0715 means a fault in the transmission input/turbine speed sensor circuit — the sensor that reports transmission input shaft speed.
P0716 means the transmission input/turbine speed sensor signal is out of range — the sensor that reports how fast the input shaft/turbine is turning.
P0720 means a fault in the transmission output speed sensor circuit — the sensor that reports gearbox output (road) speed for shift control.
P0725 means a fault in the engine speed input to the transmission controller — the transmission isn't getting a valid engine-RPM signal.
P0730 means the transmission is not achieving the expected gear ratio — the input vs output speed doesn't match the commanded gear.
P0740 means a fault in the torque converter clutch (lock-up) circuit — the clutch that locks the converter for efficiency at cruise.
P0741 means the torque converter clutch (TCC) is not locking up when commanded (stuck off) — so the converter keeps slipping instead of coupling.
P0742 means the torque converter clutch (TCC) is staying applied (stuck on) when it should release — the converter won't unlock.
P0748 means an electrical fault in transmission pressure control solenoid "A" — the solenoid that regulates line/clutch pressure.
P0750 means a fault in shift solenoid "A" — one of the electro-hydraulic valves the transmission uses to change gears.
P0793 means a fault in the transmission intermediate shaft speed sensor circuit — a sensor some gearboxes use for precise ratio/shift control.
P0812 means a fault in the reverse input circuit — the signal that tells modules the transmission is (or should be) in reverse.
P0850 means a fault in the park/neutral position (PNP) switch input — the signal that confirms the transmission is in Park or Neutral for starting.
On Ford vehicles, P1000 means the onboard diagnostic monitors have not finished running — usually seen after a battery disconnect or a cleared code, not a fault in itself.
On Volkswagen vehicles, P1128 means the long-term fuel trim on bank 1 has hit its limit because the engine is running lean — the ECM is adding fuel but can't keep up.
On Ford vehicles, P1131 means the upstream heated oxygen sensor on bank 1 is indicating a lean condition / lack of switching — the mixture is reading lean.
On Chevrolet vehicles, P1133 means the upstream oxygen sensor (bank 1, sensor 1) is not switching between rich and lean often enough — a lazy sensor.
On Toyota vehicles, P1135 means a fault in the air/fuel-ratio (A/F) sensor heater circuit for bank 1, sensor 1 — the wideband sensor Toyota uses upstream.
On Volkswagen vehicles, P1136 means the additive (idle) fuel-trim system on bank 1 is at its lean limit — the engine runs lean, especially at idle.
On Nissan vehicles, P1148 means the closed-loop fuel control on bank 1 is not working — the ECM can't use the O2/A-F sensor feedback to trim the mixture.
On Ford vehicles, P1151 means the upstream heated oxygen sensor on bank 2 is indicating a lean condition — the same lean fault as P1131 but on the other cylinder bank.
On Toyota vehicles, P1155 means a fault in the air/fuel-ratio (A/F) sensor heater circuit for bank 2, sensor 1 — the same fault as P1135 on the other bank.
On Chevrolet vehicles, P1258 means the engine has entered coolant-overtemperature protection mode — GM cuts fuel to some cylinders to protect the engine from overheating.
On Honda vehicles, P1259 means a fault in the Honda VTEC variable valve timing/lift system on bank 1 — VTEC isn't engaging correctly.
On Ford vehicles, P1260 means the Ford PATS anti-theft system has detected a theft condition or an unrecognised key and immobilised the engine.
On Toyota vehicles, P1300 means a fault in the igniter/ignition coil circuit on bank 1 — the ECM isn't seeing a correct ignition confirmation signal.
On Nissan vehicles, P1320 means a fault in the primary ignition signal circuit — the ECM isn't seeing a correct ignition (coil/power transistor) signal.
On Chevrolet vehicles, P1336 means the crankshaft position system variation (CASE) relearn has not been performed — needed so the ECM can accurately detect misfires.
On Toyota vehicles, P1349 means a fault in the variable valve timing (VVT/VVT-i) system on bank 1 — the cam timing isn't responding as commanded.
On Honda vehicles, P1399 means a random/multiple-cylinder misfire detected by the Honda ECM — combustion is failing across cylinders.
On Subaru vehicles, P1443 means a malfunction in the evaporative emissions (EVAP) vent control solenoid valve — the valve that seals the charcoal canister so the system can run leak tests.
On Ford vehicles, P1450 means the evaporative (EVAP) system cannot relieve fuel-tank vacuum — excess vacuum is building in the tank.
On Honda vehicles, P1457 means an evaporative emissions (EVAP) leak detected on the charcoal-canister side of the system.
On Dodge vehicles, P1684 means the battery was disconnected or went dead within roughly the last 50 engine warm-up cycles — an informational note, not a fault in itself.
U0001 means a general fault on the high-speed CAN communication bus — the main data network modules use to talk to each other.
U0073 means communication bus "A" has gone "off" (bus-off) — a module has stopped transmitting because it detected too many bus errors.
U0100 means a module has lost communication with the engine control module (ECM/PCM) — it can no longer exchange data with the engine computer.
U0101 means lost communication with the transmission control module (TCM) — the network can no longer talk to the transmission computer.
U0121 means lost communication with the anti-lock brake system (ABS) control module — the network can no longer talk to the ABS/stability computer.
U0126 means lost communication with the steering angle sensor module — the sensor that tells stability control which way the wheel is turned.
U0140 means lost communication with the body control module (BCM) — the module that manages lights, locks, and many body electrics.
U0155 means lost communication with the instrument panel cluster (IPC) — the gauges/display module on the network.
U0164 means lost communication with the HVAC (climate control) module — the network can no longer talk to the heating/AC controller.
U0300 means internal control module software incompatibility — two modules have software versions that don't match/communicate correctly.
U0401 means a module received invalid data from the engine control module (ECM/PCM) — the ECM is on the network but sending data that fails plausibility checks.
U0415 means a module received invalid data from the ABS control module — the ABS module is on the network but its data fails plausibility checks.
