AutoLogicTools
Tools
OBD-II connector linked to a graphite sedan and its diagnostic systems

Diagnostic library

1,801 OBD-II Trouble Code GuidesA code is the first clue.

Use the AutoLogicTools library to understand what a scan-tool result means. A code is a starting point for diagnosis, not proof that a particular part has failed.

1,801 current guides4 systems · 17 code rangesSeverity & next steps
Live code library

Start typing to search all 1,801 codes, or browse by system and code range below.

Browse by system

Every code belongs to a system, named by the letter it starts with. Larger systems are split into code ranges so each page stays readable — the number in each link is how many codes are published there.

Powertrain codes (P)

1,387 codes

Engine, transmission, fuel, ignition and emissions. By far the largest group, and where most check engine lights land.

Chassis codes (C)

60 codes

ABS, traction control, stability control, steering and suspension.

Body codes (B)

73 codes

Airbags and restraints, climate control, lighting and cabin electronics.

Network codes (U)

281 codes

Module-to-module communication, bus faults and software compatibility between control units.

Code families and subjects

Some codes only make sense as a set — the same fault across lettered slots, or one subject spread over a grid of solenoids and fault modes. These hubs cover a whole group at once and list every code in it.

Shift Solenoid Codes (43)Pressure Control Solenoid Codes (27)Lost Communication With Restraints System Sensor (10)Software Incompatibility With Hybrid/EV Battery Interface Control Module (10)Invalid Data Received From Restraints System Sensor (8)Throttle/Pedal Position Sensor Maximum Stop Performance (6)Throttle/Pedal Position Sensor Minimum Stop Performance (6)Invalid Data Received From Body Control Module (5)Invalid Data Received From Gateway (5)Lost Communication With Gateway (5)Lost Communication with Body Control Module (4)Software Incompatibility With Active Grille Air Shutter Module (4)Software Incompatibility With Battery Energy Control Module (3)Driver Seat Occupant Classification Sensor (Subfault) (2)Driver Seat Occupant Position Sensor (Subfault) (2)Invalid Data Received From Automated Driving System Control Module (2)Invalid Data Received From Automated Driving System Interface Module (2)Invalid Data Received From Battery Energy Control Module (2)Invalid Data Received From Chassis Control Module (2)Invalid Data Received From Exhaust Gas Recirculation Control Module (2)Invalid Data Received From Information Center (2)Invalid Data Received From Power Steering Control Module (2)Invalid Data Received From Rocker Arm Control Module (2)Invalid Data Received From Suspension Control Module (2)Invalid Data Received From Turbocharger/Supercharger Control Module (2)Invalid Data Received From Vacuum Sensor (2)Lost Communication with Battery Energy Control Module (2)Passenger Seat Occupant Classification Sensor (Subfault) (2)Software Incompatibility With Body Control Module (2)

Main automotive tools

Pair a code lookup with the calculators to plan parts, labor, and your repair budget.

VIN Decoder & Vehicle Specs

Decode a VIN and view vehicle year, make, model, engine details, body style, manufacturing info, confidence notes, and verification checklist.

Car Payment Calculator

Estimate monthly auto loan payment, amount financed, total interest, taxes, fees, and total loan cost.

MPG & Fuel Cost Calculator

Estimate fuel cost, gallons used, cost per mile, and savings between vehicles with different MPG ratings.

Repair Cost Estimator

Estimate common car repair costs using repair type, vehicle category, parts, labor hours, and labor rate.

Car Value Estimator

Estimate a rough used car value range based on vehicle year, mileage, condition, vehicle type, and sale scenario.

Tire Size Calculator

Compare tire sizes, sidewall height, diameter, circumference, revolutions per mile, and speedometer impact.

Maintenance Cost Calculator

Estimate routine vehicle maintenance costs, monthly budget, annual cost, cost per mile, and service milestones.

About this code library

AutoLogicTools code pages provide general OBD-II trouble code information for planning conversations with a mechanic. A scan-tool reading is only the starting point. Verify diagnoses, parts, and labor with a qualified automotive professional before approving any repair.