OBD2 Fault Code Library

Free lookup for thousands of OBD2 trouble codes: filter by family, read short meanings, and open deeper articles. Desktop ELM327 scanner with live data and AI guidance.

OBD2 symptoms

Look up diagnostic trouble codes by what the car is doing: misfire, overheating, rough idle, a check engine light, and other common symptoms.

• Engine misfire
• Engine overheating
• Rough idle
• Check engine light
• Poor fuel economy
• Hard starting
• Engine stalling
• Catalytic converter efficiency
• Oxygen sensor fault
• EVAP leak
• Thermostat not reaching temperature
• Lean air-fuel mixture
• Rich air-fuel mixture
• EGR flow fault
• Engine knock
• Charging system
• Throttle position
• Mass airflow sensor
• Turbo underboost
• Coolant temperature sensor
• Transmission fault

• P1316 — OBD2 code P1316 flags a problem with the sensor and actuator circuits (A/C clutch circuit fault). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, faulty sensor or actuator of the affected circuit, corroded, loose or damaged connector.
• P1317 — P1317 — Misfire Monitor AICE Chip Fault. A fault in the engine misfire monitoring. Short, gentle driving to a shop is usually possible. Typical causes: clogged or leaking fuel injector, low compression in the affected cylinder(s), incorrect fuel pressure or a weak fuel pump.
• P1318 — P1318 — Timer Position Sensor Circuit Malfunction. P1318 identifies a fault in the timer position sensor circuit.
• P1319 — P1319 — Timer Position Sensor Circuit Fault. P1319 affects a critical engine timing reference and may cause stalling or a no-start condition.
• P1320 — P1320 — Distributor Signal Interrupt. P1320 indicates an interrupted distributor reference signal, which can cause stalling, rough running, or a no-start condition.
• P1321 — P1321 — Cylinder 9 Ignition Coil Short. P1321 indicates a short in the cylinder 9 ignition path, and continued misfire can damage the catalytic converter.
• P1324 — P1324 — Cylinder 12 Ignition Coil Primary Short. P1324 indicates a short in the cylinder 12 ignition-coil circuit and should be diagnosed promptly.
• P1325 — P1325 — Cylinder 9 Ignition Coil Open Circuit. P1325 can prevent cylinder 9 from firing and create a confirmed misfire.
• P1326 — P1326 — Cylinder 10 Positive-to-Negative Ignition Circuit Open. P1326 can leave cylinder 10 without proper ignition and may cause rough running or power loss.
• P1327 — P1327 — Cylinder 11 Coil Circuit Open. P1327 can prevent normal ignition on cylinder 11, causing rough running, misfire, and reduced power.
• P1328 — P1328 — Cylinder 12 Ignition Coil Open Circuit. P1328 can leave cylinder 12 without reliable ignition, causing rough running and reduced power.
• P1329 — P1329 — Injector Control Pressure Running Fault. P1329 should be diagnosed promptly because pressure outside its expected running range can cause misfires, stalling, power loss, and injector damage.
• P1330 — P1330 — Injector Control Pressure Engine-Running Fault. P1330 indicates that expected injector-control pressure was not detected while the engine was running.
• P1331 — P1331 — Turbo High-Pressure Boost Control Open Circuit. P1331 can leave turbocharger boost poorly controlled, including excessive boost in some designs.
• P1332 — P1332 — High-Pressure Boost Control Low Voltage. P1332 can prevent the turbo from producing its commanded boost, causing sluggish performance or reduced-power operation.
• P1333 — P1333 — Turbo High-Side Boost Voltage Too High. P1333 warrants prompt diagnosis because an electrical fault can leave boost control ineffective or allow unintended boost.
• P1334 — P1334 — EGR Performance at Minimum Throttle Position. P1334 indicates an EGR-flow performance fault during acceleration from minimum throttle.
• P1335 — P1335 — EGR Performance at Minimum Throttle Position. P1335 is generally not an immediate stop condition, but rough idle, hesitation, stalling, smoke, or substantial power loss should prompt avoiding further driving until the fault is repaired.
• P1337 — P1337 — Throttle Position Output Signal Fault. P1337 can affect throttle-command accuracy and may trigger reduced-power operation.
• P1338 — P1338 — Fuel Pump Module Communication Failure. P1338 can cause incorrect fuel-pump control, hesitation, or stalling.
• P1339 — P1339 — Fuel Pump Control Module Communication Failure. P1339 can disrupt fuel-pump control and produce stalling or a no-start condition.
• P1340 — OBD2 code P1340 flags a problem with the engine misfire monitoring (misfire rate catalyst damage fault - bank 2). Short, gentle driving to a shop is usually possible. Common culprits: incorrect fuel pressure or a weak fuel pump, faulty crankshaft/camshaft position signal, failed ignition coil or coil wiring.
• P1342 — P1342 — Pedal Demand Sensor A Range/Performance. P1342 can affect how the powertrain interprets accelerator pedal demand.
• P1344 — P1344 — Pedal Demand Sensor C Range/Performance Fault. P1344 can affect how the powertrain interprets accelerator demand, so reduced response or fail-safe operation may occur.