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Car / OBD-II codes
P, C, B and U codes with manufacturer-specific causes, severity ratings, and real fix costs.
68 guidesEquipment fault codes
Mini-splits, generators, forklifts and industrial gear — the same in-depth, hand-researched guides.
4 guidesReal repair costs
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Equipment guides
Mini-splits and industrial equipment fault codes.
Indoor / Outdoor Communication Error (EL01)
Mrcool · DIY Mini-split
Indoor / Outdoor Communication Error
Mitsubishi · Mini-split
Refrigerant Leak / Low Charge Detected (EL0C)
Mrcool · DIY Mini-split
Communication Fault Between Indoor and Outdoor Units
Daikin · Mini-split / VRV
In-depth car code guides
Hand-researched OBD-II diagnostics, costs and fixes.
Left Front Wheel Speed Sensor Circuit
Intake Camshaft Timing Over-Advanced (Bank 1)
Exhaust Camshaft Timing Over-Advanced (Bank 1)
Crankshaft/Camshaft Position Correlation (Bank 1, Sensor A)
Crankshaft/Camshaft Position Correlation (Bank 1, Sensor B)
Mass Air Flow (MAF) Sensor Range/Performance Problem
Mass Air Flow (MAF) Sensor Circuit Low Input
Intake Air Temperature (IAT) Sensor Circuit High
Engine Coolant Temperature (ECT) Sensor Circuit High
Insufficient Coolant Temperature for Closed Loop
Coolant Thermostat Below Regulating Temperature
O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1)
O2 Sensor Slow Response (Bank 1, Sensor 1)
O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)
O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 2)
System Too Lean (Bank 1)
P0171 System Too Lean on Ford: Causes, Fixes & Cost
P0171 on Honda & Acura: System Too Lean — Causes, Fixes & Cost
P0171 on Toyota & Lexus: System Too Lean — Causes, Fixes & Cost
System Too Rich (Bank 1)
System Too Lean (Bank 2)
System Too Rich (Bank 2)
Throttle/Pedal Position Sensor B Circuit High
Turbocharger/Supercharger Overboost Condition
Turbocharger/Supercharger Underboost Condition
Random/Multiple Cylinder Misfire Detected
P0300 Random Misfire on Ford: Causes, Fixes & Cost
P0300 Random Misfire on Toyota & Lexus: Causes, Fixes & Cost
Cylinder 1 Misfire Detected
P0301 Cylinder 1 Misfire on Ford: Causes, Fixes & Cost
P0301 Cylinder 1 Misfire on Honda & Acura: Causes, Fixes & Cost
Cylinder 2 Misfire Detected
Cylinder 3 Misfire Detected
Cylinder 4 Misfire Detected
Cylinder 5 Misfire Detected
Cylinder 6 Misfire Detected
Knock Sensor 1 Circuit Low (Bank 1)
Crankshaft Position Sensor Circuit Malfunction
Camshaft Position Sensor Circuit Malfunction
Camshaft Position Sensor Range/Performance
Exhaust Gas Recirculation (EGR) Flow Insufficient
Secondary Air Injection System Incorrect Flow
Catalyst System Efficiency Below Threshold (Bank 1)
P0420 on Chevrolet & GMC: Catalyst Efficiency — Causes, Fixes & Cost
P0420 on Ford: Catalyst Efficiency Below Threshold — Causes, Fixes & Cost
P0420 on Toyota & Lexus: Causes, Fixes & Cost
Catalyst System Efficiency Below Threshold (Bank 2)
EVAP System Malfunction
P0440 EVAP System Malfunction on Ford: Causes, Fixes & Cost
P0440 EVAP System Malfunction on Toyota & Lexus: Causes, Fixes & Cost
EVAP System Small Leak Detected
EVAP Vent Control Circuit Malfunction
EVAP System Large Leak Detected
EVAP System Very Small Leak Detected
EVAP Leak Detected (Loose/Faulty Fuel Cap)
Idle Air Control (IAC) System Malfunction
Idle Air Control System RPM Lower Than Expected
Idle Air Control System RPM Higher Than Expected
Engine Oil Pressure Sensor Range/Performance
System Voltage High
ECM/PCM Processor Fault
Transmission Control System Malfunction
Torque Converter Clutch Circuit Malfunction
Torque Converter Clutch Performance / Stuck Off
Post-Catalyst Fuel Trim System Too Lean (Bank 1)
O2 Sensor Signal Stuck Lean (Bank 1, Sensor 1)
Lost Communication With ECM/PCM A
Lost Communication With TCM