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

• C1028 — C1028 — C1028 — ABS Primary Circuit Wheel Pressure: Causes, Symptoms & Fix. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: faulty ABS module or pump motor, blown fuse or low voltage to the ABS module, damaged sensor wiring or corroded connector.
• C1029 — C1029 — C1029 — ABS Primary Circuit Pressure Lower Than Secondary: Causes, Symptoms & Fix. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: damaged tone (reluctor) ring on the hub, failed wheel speed sensor, damaged sensor wiring or corroded connector.
• C102A — C102A — C102A — Brake Secondary Circuit Pressure Mismatch Between Wheels: Causes, Symptoms & Fix. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: blown fuse or low voltage to the ABS module, damaged sensor wiring or corroded connector, failed wheel speed sensor.
• C1091 — OBD2 code C1091 flags a problem with the sensor and actuator circuits (speed wheel sensor all coherency failure). The car is usually drivable while you plan the repair. Common culprits: control module driver fault, faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit.
• C1095 — C1095 — ABS Hydraulic Pump Motor Circuit Failure. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: blown fuse or low voltage to the ABS module, faulty ABS module or pump motor, damaged tone (reluctor) ring on the hub.
• C1096 — C1096 — ABS Hydraulic Pump Motor Circuit Open. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: faulty ABS module or pump motor, damaged tone (reluctor) ring on the hub, damaged sensor wiring or corroded connector.
• C1097 — C1097 — ABS Hydraulic Pump Motor Circuit Short To Ground. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: failed wheel speed sensor, faulty ABS module or pump motor, damaged tone (reluctor) ring on the hub.
• C1098 — C1098 — ABS Hydraulic Pump Motor Circuit Short To Battery. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: blown fuse or low voltage to the ABS module, damaged tone (reluctor) ring on the hub, failed wheel speed sensor.
• C1100 — C1100 — ABS Pump Switch Circuit Failure. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: faulty ABS module or pump motor, blown fuse or low voltage to the ABS module, failed wheel speed sensor.
• C1101 — C1101 — ABS Hydraulic Valve Circuit Failure. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: damaged tone (reluctor) ring on the hub, blown fuse or low voltage to the ABS module, faulty ABS module or pump motor.
• C1102 — C1102 — ABS Acceleration Switch Circuit Failure. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: failed wheel speed sensor, faulty ABS module or pump motor, damaged tone (reluctor) ring on the hub.
• C1103 — OBD2 code C1103 flags a problem with the ABS / stability control (ABS hydraulic brake switch circuit failure). Short, gentle driving to a shop is usually possible. Common culprits: blown fuse or low voltage to the ABS module, failed wheel speed sensor, damaged tone (reluctor) ring on the hub.
• C1104 — Traction Control Active Lamp - Circuit Short to Battery (C1104): a chassis (brakes/steering/suspension) fault affecting the ABS / stability control. Short, gentle driving to a shop is usually possible. Most often caused by damaged sensor wiring or corroded connector, blown fuse or low voltage to the ABS module, failed wheel speed sensor.
• C1105 — Traction Control Disable Lamp - Circuit Short to Battery (C1105): a chassis (brakes/steering/suspension) fault affecting the ABS / stability control. Short, gentle driving to a shop is usually possible. Most often caused by damaged tone (reluctor) ring on the hub, damaged sensor wiring or corroded connector, failed wheel speed sensor.
• C1106 — Traction Control Disable Switch Circuit Short to Battery (C1106): a chassis (brakes/steering/suspension) fault affecting the ABS / stability control. Short, gentle driving to a shop is usually possible. Most often caused by damaged sensor wiring or corroded connector, failed wheel speed sensor, faulty ABS module or pump motor.
• C1107 — C1107 — ABS Function Enabled Input Circuit Failure. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: damaged tone (reluctor) ring on the hub, damaged sensor wiring or corroded connector, failed wheel speed sensor.
• C1109 — Speed Control Actuator Assembly Cable Release Failure (C1109): a chassis (brakes/steering/suspension) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by corroded, loose or damaged connector, control module driver fault, poor ground connection.
• C1110 — OBD2 code C1110 flags a problem with the ignition system (ABS power relay coil circuit failure). Short, gentle driving to a shop is usually possible. Common culprits: failed ignition coil or coil pack, worn spark plugs or wrong plug gap, damaged coil wiring or connector.
• C1111 — ABS Power Relay Coil Open Circuit (C1111): a chassis (brakes/steering/suspension) fault affecting the ignition system. Short, gentle driving to a shop is usually possible. Most often caused by failed ignition coil or coil pack, damaged coil wiring or connector, moisture or oil in the spark plug wells.
• C1112 — ABS Power Relay Coil Short Circuit To Ground (C1112): a chassis (brakes/steering/suspension) fault affecting the ignition system. Short, gentle driving to a shop is usually possible. Most often caused by faulty ignition control circuit in the ECM, moisture or oil in the spark plug wells, failed ignition coil or coil pack.
• C1113 — ABS Power Relay Coil Short Circuit To Battery (C1113): a chassis (brakes/steering/suspension) fault affecting the ignition system. Short, gentle driving to a shop is usually possible. Most often caused by worn spark plugs or wrong plug gap, failed ignition coil or coil pack, damaged coil wiring or connector.
• C1114 — OBD2 code C1114 flags a problem with the ABS / stability control (ABS power relay output short circuit to ground). Short, gentle driving to a shop is usually possible. Common culprits: blown fuse or low voltage to the ABS module, damaged tone (reluctor) ring on the hub, faulty ABS module or pump motor.
• C1115 — ABS Power Relay Output Short Circuit To Battery (C1115): a chassis (brakes/steering/suspension) fault affecting the ABS / stability control. Short, gentle driving to a shop is usually possible. Most often caused by blown fuse or low voltage to the ABS module, damaged sensor wiring or corroded connector, failed wheel speed sensor.
• C1116 — Starter Motor Circuit Failure (C1116): a chassis (brakes/steering/suspension) fault affecting the sensor and actuator circuits. The car is usually drivable while you plan the repair. Most often caused by corroded, loose or damaged connector, control module driver fault, blown fuse feeding the circuit.