Every code Codewise explains

252 OBD-II trouble codes — generic and manufacturer-specific (P1) across 14 brands. Each has a plain-English meaning, an honest safe-to-drive verdict, the likely causes, and what to check first. Or decode any code in the live tool →

C0xxx codes

• C0035 Left Front Wheel Speed Sensor Circuit
• C0040 Right Front Wheel Speed Sensor Circuit
• C0045 Left Rear Wheel Speed Sensor Circuit
• C0050 Right Rear Wheel Speed Sensor Circuit
• C0561 ABS System Disabled

P0xxx codes

• P0011 Camshaft Timing (Bank 1) Over-Advanced / Performance
• P0016 Crankshaft / Camshaft Position Correlation (Bank 1)
• P0025 Camshaft Position 'B' (Exhaust) Timing Over-Retarded (Bank …
• P0087 Fuel Rail / System Pressure Too Low
• P0101 Mass Air Flow (MAF) Range / Performance
• P0102 MAF Circuit Low Input
• P0106 MAP Sensor Range / Performance
• P0107 MAP Sensor Circuit Low Voltage
• P0108 MAP Sensor Circuit High Voltage
• P0111 Intake Air Temperature Sensor Range / Performance
• P0112 Intake Air Temperature Sensor Circuit Low
• P0113 Intake Air Temp (IAT) Sensor High Input
• P0116 Engine Coolant Temperature Sensor Range / Performance
• P0117 Engine Coolant Temperature Sensor Circuit Low
• P0118 Engine Coolant Temperature Sensor Circuit High
• P0121 Throttle Position Sensor Range / Performance
• P0122 Throttle Position Sensor Circuit Low Voltage
• P0123 Throttle Position Sensor Circuit High Voltage
• P0125 Insufficient Coolant Temp for Closed-Loop Fuel Control
• P0128 Coolant Temp Below Thermostat Regulating Temp
• P0131 O2 Sensor Low Voltage (Bank 1, Sensor 1)
• P0133 O2 Sensor Slow Response — Bank 1, Sensor 1
• P0134 O2 Sensor No Activity — Bank 1, Sensor 1
• P0135 O2 Sensor Heater Circuit (Bank 1, Sensor 1)
• P0137 O2 Sensor Low Voltage — Bank 1, Sensor 2
• P0138 O2 Sensor High Voltage — Bank 1, Sensor 2
• P0141 O2 Sensor Heater Circuit Malfunction — Bank 1, Sensor 2
• P0151 O2 Sensor Low Voltage — Bank 2, Sensor 1
• P0157 O2 Sensor Low Voltage — Bank 2, Sensor 2
• P0161 O2 Sensor Heater Circuit Malfunction — Bank 2, Sensor 2
• P0170 Fuel Trim Malfunction (Bank 1)
• P0171 System Too Lean (Bank 1)
• P0172 System Too Rich (Bank 1)
• P0174 System Too Lean (Bank 2)
• P0175 System Too Rich — Bank 2
• P0193 Fuel Rail Pressure Sensor Circuit High
• P0201 Injector Circuit Malfunction — Cylinder 1
• P0202 Injector Circuit Malfunction — Cylinder 2
• P0203 Injector Circuit Malfunction — Cylinder 3
• P0204 Injector Circuit Malfunction — Cylinder 4
• P0222 Throttle Position Sensor B Circuit Low
• P0223 Throttle Position Sensor B Circuit High
• P0234 Turbocharger / Supercharger Overboost Condition
• P0299 Turbocharger Underboost
• P0300 Random / Multiple Cylinder Misfire
• P0301 Cylinder 1 Misfire Detected
• P0302 Cylinder 2 Misfire Detected
• P0303 Cylinder 3 Misfire Detected
• P0304 Cylinder 4 Misfire Detected
• P0305 Cylinder 5 Misfire Detected
• P0306 Cylinder 6 Misfire Detected
• P0307 Cylinder 7 Misfire Detected
• P0308 Cylinder 8 Misfire Detected
• P0316 Misfire Detected on Startup (First 1000 Revolutions)
• P0325 Knock Sensor 1 Circuit — Bank 1
• P0330 Knock Sensor 2 Circuit — Bank 2
• P0335 Crankshaft Position Sensor Circuit
• P0340 Camshaft Position Sensor Circuit
• P0341 Camshaft Position Sensor Range/Performance - often TIMING C…
• P0351 Ignition Coil A Primary/Secondary Circuit
• P0352 Ignition Coil B Primary/Secondary Circuit
• P0354 Ignition Coil D Primary/Secondary Circuit
• P0401 EGR Insufficient Flow
• P0402 Exhaust Gas Recirculation Flow Excessive
• P0403 Exhaust Gas Recirculation Circuit
• P0404 Exhaust Gas Recirculation Circuit Range/Performance
• P0405 EGR Sensor A Circuit Low
• P0410 Secondary Air Injection System Malfunction
• P0411 Secondary Air Injection System — Incorrect Flow
• P0420 Catalyst Efficiency Below Threshold (Bank 1)
• P0430 Catalyst Efficiency Below Threshold (Bank 2)
• P0440 EVAP System Malfunction (general)
• P0441 EVAP Emission Control System — Incorrect Purge Flow
• P0442 EVAP Small Leak Detected
• P0443 EVAP Purge Control Valve Circuit
• P0446 EVAP Vent Control Circuit
• P0449 EVAP Vent Valve / Solenoid Circuit
• P0451 EVAP Pressure Sensor Range/Performance
• P0452 EVAP Pressure Sensor Circuit Low
• P0453 EVAP Pressure Sensor Circuit High
• P0455 EVAP Large Leak Detected
• P0456 EVAP Very Small Leak Detected
• P0457 EVAP System Leak Detected — Fuel Cap Loose/Off
• P0461 Fuel Level Sensor Circuit Range/Performance
• P0480 Cooling Fan 1 Control Circuit
• P0496 EVAP System High Purge Flow
• P0505 Idle Control System Malfunction
• P0506 Idle Speed Lower Than Expected
• P0507 Idle Speed Higher Than Expected
• P0511 Idle Air Control Circuit
• P0513 Invalid SKIM Key (Sentry Key Immobilizer)
• P0520 Engine Oil Pressure Sensor/Switch Circuit
• P0521 Engine Oil Pressure Sensor / Switch Range
• P0522 Engine Oil Pressure Sensor Circuit Low
• P0523 Engine Oil Pressure Sensor Circuit High
• P0532 A/C Refrigerant Pressure Sensor Circuit Low
• P0562 System Voltage Low
• P0600 Serial Communication Link Malfunction
• P0601 Internal Control Module Memory Check Sum Error
• P0603 Internal Control Module Keep Alive Memory (KAM) Error
• P0605 Internal Control Module ROM Error
• P0606 PCM / ECM Processor Fault
• P0641 Sensor Reference Voltage 'A' Circuit Open / Out of Range (5…
• P0651 Sensor Reference Voltage 'B' Circuit Open / Out of Range
• P0685 ECM/PCM Power Relay Control Circuit / Open
• P0688 ASD / ECM-PCM Power Relay Sense Circuit Open
• P0700 Transmission Control System Malfunction (request MIL)
• P0705 Transmission Range Sensor Circuit Malfunction
• P0711 Transmission Fluid Temperature Sensor Circuit Range/Perform…
• P0712 Transmission Fluid Temperature Sensor Low Input
• P0713 Transmission Fluid Temperature Sensor High Input
• P0715 Input/Turbine Speed Sensor Circuit
• P0716 Input/Turbine Speed Sensor Circuit Range/Performance
• P0717 Input/Turbine Speed Sensor Circuit No Signal
• P0720 Output Speed Sensor Circuit
• P0722 Output Speed Sensor Circuit No Signal
• P0730 Incorrect Gear Ratio
• P0731 Gear 1 Incorrect Ratio
• P0732 Gear 2 Incorrect Ratio
• P0733 Gear 3 Incorrect Ratio
• P0734 Gear 4 Incorrect Ratio
• P0740 Torque Converter Clutch Circuit Malfunction
• P0741 Torque Converter Clutch Performance / Stuck Off
• P0742 Torque Converter Clutch Circuit Stuck On
• P0743 Torque Converter Clutch Solenoid Circuit Electrical
• P0746 Pressure Control Solenoid Performance / Stuck Off
• P0748 Pressure Control Solenoid Electrical
• P0750 Shift Solenoid A Malfunction
• P0751 Shift Solenoid A Performance / Stuck Off
• P0755 Shift Solenoid B Malfunction
• P0756 Shift Solenoid B Performance / Stuck Off
• P0846 Transmission Fluid Pressure Sensor/Switch 'B' Circuit Range…
• P0894 Transmission Component Slipping

P1xxx codes

• P1000 OBD System Readiness Test Not Complete
• P1030 Valvetronic Control Motor Position Deviation (Bank 1)
• P1083 Fuel Control Mixture Lean (Bank 1, Sensor 1)
• P1085 Fuel Control Mixture Lean (Bank 2, Sensor 1)
• P1086 Tumble Generator Valve #2 (LH) Position Sensor Circuit Low …
• P10DF DISA / intake-manifold runner control fault (modern BMW hex…
• P1100 BARO (Barometric Pressure) Sensor Circuit
• P1103 Turbocharger Wastegate Actuator
• P1104 Turbocharger Wastegate Solenoid
• P1105 Fuel Pressure Regulator / Solenoid Control
• P1106 Barometric Pressure (BARO) Sensor Circuit Range/Performance
• P1116 Engine Coolant Temperature Sensor Out of Self-Test Range
• P1125 Throttle Control Motor Circuit (ETCS)
• P1128 Long-Term Fuel Trim Mult., Bank 1 System Too Lean
• P1130 Air-Fuel Ratio Sensor Circuit Range/Performance (Bank 1 Sen…
• P1131 Lack of Upstream HO2S Switch — Indicates Lean (Bank 1)
• P1132 Lack of Upstream HO2S Switch — Indicates Rich (Bank 1)
• P1133 HO2S Insufficient Switching (Bank 1 Sensor 1)
• P1135 Air/Fuel Ratio Sensor Heater Circuit Response (Bank 1 Senso…
• P1136 Long-Term Fuel Trim Add. Fuel, Bank 1 System Too Lean
• P1142 Mass Air Flow (MAF) Sensor Circuit Low Input
• P1148 Closed Loop Control Function (Bank 1) Inoperative
• P1151 Lack of Upstream HO2S Switch — Indicates Lean (Bank 2)
• P1153 HO2S Insufficient Switching (Bank 2 Sensor 1)
• P1155 Air/Fuel Ratio Sensor Heater Circuit (Bank 2 Sensor 1)
• P1162 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Slow Response
• P1166 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Heater System Electr…
• P1167 Air/Fuel Ratio (A/F) Sensor (Sensor 1) Heater System Malfun…
• P1170 Front HO2S (Bank 1 Sensor 1) Circuit Fixed / Inactive
• P1217 Engine Over Temperature (Overheat)
• P1235 Throttle / MAF Plausibility (Volumetric Efficiency)
• P1259 PATS Function Fault — VIP / Anti-Theft System Active
• P1260 Theft Detected — Vehicle/Engine Immobilized
• P1270 Engine RPM or Vehicle Speed Limiter Reached
• P1273 Air/Fuel (A/F) Sensor 1 (Bank 1) Lean Shift / Lean Mixture
• P1278 Air/Fuel (A/F) Sensor 1 (Bank 1) Slow Response
• P1281 Engine Is Cold Too Long (slow warm-up)
• P1289 Cylinder Head Temperature (CHT) Sensor High Input
• P1296 Cooling System Malfunction (coolant temp / thermostat)
• P1297 Electrical Load Detector (ELD) Circuit Low Voltage
• P1299 Cylinder Head Over-Temperature Protection Active
• P1300 Igniter Circuit Malfunction No. 1
• P1320 Ignition Signal Circuit Malfunction
• P1326 Knock Sensor Detection System (KSDS) - rod-knock detection
• P1335 No Crankshaft Position Sensor Signal (Engine Running)
• P1336 Crankshaft/Camshaft Position Sensor Input Signal Error (PIP…
• P1340 Camshaft/Crankshaft Position Sensor Signals Out of Sequence
• P1345 Crankshaft/Camshaft Position Correlation
• P1346 Variable Valve Timing (VVT) Sensor / Camshaft Position Rang…
• P1349 Variable Valve Timing (VVT) System Malfunction (Bank 1)
• P1351 Ignition Control (IC) Circuit High Voltage / Open
• P1361 Ignition Control (IC) Circuit Low Voltage
• P1380 Misfire Detected — Rough Road Data Not Available (EBCM)
• P1381 Misfire Detected — No EBCM/PCM Serial Data
• P1389 No ASD Relay Output Voltage at PCM
• P1391 Intermittent Loss of CMP or CKP Signal
• P1399 Random Cylinder Misfire Detected
• P1400 DPFE (EGR) Sensor Circuit Low Voltage
• P1404 EGR Closed Position Performance (valve stuck OPEN)
• P1441 EVAP System Flow During Non-Purge Conditions
• P1443 EVAP Purge Control Valve / Solenoid Fault
• P1444 EVAP Canister Purge Volume Control Solenoid Valve
• P1448 EVAP Canister Vent Control Valve (Stuck Open)
• P1450 Unable to Bleed Up Fuel Tank Vacuum (EVAP)
• P1451 EVAP Canister Vent Solenoid Circuit Malfunction
• P1456 EVAP Control System Leakage (Fuel Tank System)
• P1457 EVAP Control System Leakage (EVAP Canister System)
• P1491 EGR Valve Insufficient Lift
• P1494 EVAP Leak Detection Pump (LDP) Pressure Switch Condition
• P1495 EVAP Leak Detection Pump (LDP) Solenoid Circuit Condition
• P1496 EGR Valve Motor Coil '1' Open or Shorted
• P1500 Alternator FR Terminal Circuit
• P1505 Idle Air Control (IAC) System at Adaptive Clip
• P1516 Throttle Actuator Control (TAC) Module — Throttle Actuator …
• P1518 Starter Switch Circuit Low Input
• P1519 Camshaft Position Actuator 'A' (Intake) Bank 1 - stuck/seiz…
• P1520 Radiator Fan Relay 1 Circuit High Input
• P1525 Camshaft Position Actuator 'A' Control Circuit (VANOS solen…
• P1600 Serial Communication Link / PCM Communication
• P1601 Electronic Throttle System fault — throttle motor / interna…
• P1602 Immobilizer System Communication Error with PCM
• P1604 Startability Malfunction
• P1610 NATS Immobilizer - Lock Mode
• P1611 NATS Immobilizer - ID Discord / IMMU-ECM Communication
• P1620 MIL Requested by the Throttle Unit (ECM-532D) - faulty sign…
• P1626 Theft Deterrent Fuel Enable Signal Lost (PassKey/PassLock)
• P1629 Theft Deterrent — Start Enable Signal Not Received
• P1631 Theft Deterrent Start Enable Signal Not Correct (PassLock/P…
• P1633 Keep Alive Power (KAPWR) Voltage Too Low
• P1635 5-Volt Reference 1 Circuit Malfunction
• P1656 Oil Control Valve (OCV) Circuit (Bank 1)
• P1684 Battery Was Disconnected (memory cleared) — Informational
• P1685 SKIM Reports Invalid/Bad Key Received
• P1686 No SKIM Bus Message Received (PCM <-> SKIM)
• P1693 Companion DTC Stored in Other Module (PCM/TCM)
• P1715 Input/Turbine Speed Sensor (Transmission) Circuit Malfuncti…
• P1726 Electric Throttle Control System
• P1740 TCC or Overdrive Solenoid Performance
• P1750 Solenoid Assembly (Transmission)
• P1777 CVT Step Motor Circuit Malfunction
• P1778 CVT Step Motor Mechanical Malfunction

P2xxx codes

• P2006 Intake Manifold Runner / Swirl Flap Control Stuck Closed (B…
• P2015 Intake Manifold Runner Position Sensor/Switch Circuit (Bank…
• P2074 MAP/MAF — Throttle Position Correlation at Higher Load
• P2096 Post-Cat Fuel Trim Too Lean (Bank 1)
• P2187 System Too Lean at Idle (Bank 1)

U0xxx codes

• U0001 High Speed CAN Communication Bus
• U0073 Control Module Communication Bus Off
• U0100 Lost Communication With ECM/PCM
• U0101 Lost Communication With TCM
• U0121 Lost Communication With ABS Control Module
• U0140 Lost Communication With Body Control Module
• U0155 Lost Communication With Instrument Panel Cluster
• U0401 Invalid Data Received From ECM/PCM