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

• C1146 — Speed Wheel Sensor RF Circuit Open (C1146): 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, poor ground connection, open or shorted wiring in the circuit.
• C1148 — C1148 — Speed Wheel Sensor RF Coherency Fault. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, corroded, loose or damaged connector, poor ground connection.
• C1149 — Hydraulic Fluid Pressure/ Flow Circuit Failure (C1149): 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 control module driver fault, open or shorted wiring in the circuit, corroded, loose or damaged connector.
• C1150 — OBD2 code C1150 flags a problem with the sensor and actuator circuits (two speed rear axle input switch circuit short to vbatt). The car is usually drivable while you plan the repair. Common culprits: corroded, loose or damaged connector, blown fuse feeding the circuit, open or shorted wiring in the circuit.
• C1155 — C1155 — Speed Wheel Sensor LF Input Circuit Failure. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: corroded, loose or damaged connector, poor ground connection, open or shorted wiring in the circuit.
• C1156 — Speed Wheel Sensor LF Circuit Open (C1156): 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 open or shorted wiring in the circuit, corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit.
• C1157 — C1157 — Park Brake Actuator Assembly Switch Applied 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, damaged sensor wiring or corroded connector, blown fuse or low voltage to the ABS module.
• C1158 — C1158 — Speed Wheel Sensor LF Coherency Fault. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: open or shorted wiring in the circuit, control module driver fault, poor ground connection.
• C1159 — Hydraulic Fluid Pressure/ Flow Circuit Short to Gnd (C1159): 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 poor ground connection, corroded, loose or damaged connector, faulty sensor or actuator of the affected circuit.
• C1161 — Air Pressure Low Circuit Short to Gnd (C1161): 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 poor ground connection, faulty sensor or actuator of the affected circuit, open or shorted wiring in the circuit.
• C1162 — C1162 — Park Brake Switch # 2 Released Circuit Failure. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: damaged sensor wiring or corroded connector, damaged tone (reluctor) ring on the hub, failed wheel speed sensor.
• C1163 — C1163 — Park Brake Switch # 2 Applied Circuit Short to Gnd. 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.
• C1164 — C1164 — Park Brake Actuator Assembly 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.
• C1165 — Speed Wheel Sensor RR Input Circuit Failure (C1165): 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 faulty sensor or actuator of the affected circuit, control module driver fault, poor ground connection.
• C1166 — C1166 — Speed Wheel Sensor RR Input Open Circuit. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, blown fuse feeding the circuit, faulty sensor or actuator of the affected circuit.
• C1167 — C1167 — Park Brake Actuator Assembly Switch Released Circuit Short to Gnd. 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, failed wheel speed sensor.
• C1168 — Speed Wheel Sensor RR Coherency Fault (C1168): 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, open or shorted wiring in the circuit, control module driver fault.
• C1169 — OBD2 code C1169 flags a problem with the ABS / stability control (ABS fluid dumping exceeds maximum timing). Short, gentle driving to a shop is usually possible. Common culprits: failed wheel speed sensor, blown fuse or low voltage to the ABS module, damaged sensor wiring or corroded connector.
• C1170 — OBD2 code C1170 flags a problem with the sensor and actuator circuits (PRNDL switch circuit failure). The car is usually drivable while you plan the repair. Common culprits: blown fuse feeding the circuit, control module driver fault, poor ground connection.
• C1172 — C1172 — Park Brake Switch # 1 Applied 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.
• C1173 — OBD2 code C1173 flags a problem with the ABS / stability control (park brake switch # 1 released circuit short to gnd). Short, gentle driving to a shop is usually possible. Common culprits: damaged sensor wiring or corroded connector, failed wheel speed sensor, faulty ABS module or pump motor.
• C1174 — C1174 — Park Brake Switch # 2 Applied Circuit Failure. A fault in the ABS / stability control. Short, gentle driving to a shop is usually possible. Typical causes: damaged sensor wiring or corroded connector, blown fuse or low voltage to the ABS module, damaged tone (reluctor) ring on the hub.
• C1175 — C1175 — Speed Wheel Sensor LR Input Circuit Failure. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: open or shorted wiring in the circuit, blown fuse feeding the circuit, control module driver fault.
• C1176 — OBD2 code C1176 flags a problem with the sensor and actuator circuits (speed wheel sensor LR circuit open). The car is usually drivable while you plan the repair. Common culprits: poor ground connection, blown fuse feeding the circuit, open or shorted wiring in the circuit.