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.

U0537 — Invalid Data Received From Column Lock Module (U0537): a vehicle network fault affecting the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Most often caused by damaged CAN bus wiring or short to power/ground, poor grounds or low battery voltage, aftermarket equipment interfering with the bus.
U0538 — Invalid Data Received From "Digital Audio Control Module C" (U0538): a vehicle network fault affecting the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Most often caused by water ingress in harness junctions, damaged CAN bus wiring or short to power/ground, a faulty module pulling the bus down.
U0539 — Invalid Data Received From "Digital Audio Control Module D" (U0539): a vehicle network fault affecting the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Most often caused by a faulty module pulling the bus down, poor grounds or low battery voltage, water ingress in harness junctions.
U053A — U053A — Invalid Data Received From Entrapment Control Module "A". A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: poor grounds or low battery voltage, a faulty module pulling the bus down, corroded connectors, especially in wet areas.
U053B — U053B — Invalid Data Received From Image Processing Module "A". A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: damaged CAN bus wiring or short to power/ground, aftermarket equipment interfering with the bus, a faulty module pulling the bus down.
U053D — OBD2 code U053D flags a problem with the vehicle network (CAN bus) communication (invalid data received from image processing module "C"). Short, gentle driving to a shop is usually possible. Common culprits: poor grounds or low battery voltage, corroded connectors, especially in wet areas, a faulty module pulling the bus down.
U0540 — U0540 — U0540 - Invalid Data Received From Active Safety Control Module 103. A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: damaged CAN bus wiring or short to power/ground, water ingress in harness junctions, aftermarket equipment interfering with the bus.
U0541 — OBD2 code U0541 flags a problem with the vehicle network (CAN bus) communication (invalid data received from entrapment control module "B"). Short, gentle driving to a shop is usually possible. Common culprits: a faulty module pulling the bus down, aftermarket equipment interfering with the bus, water ingress in harness junctions.
U0542 — U0542 — Invalid Data Received From Headlamp Control Module "A". A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: corroded connectors, especially in wet areas, damaged CAN bus wiring or short to power/ground, water ingress in harness junctions.
U0543 — U0543 — Invalid Data Received From Headlamp Control Module "B". A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: aftermarket equipment interfering with the bus, a faulty module pulling the bus down, corroded connectors, especially in wet areas.
U0544 — U0544 — Invalid Data Received From Parking Assist Control Module "B". A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: corroded connectors, especially in wet areas, damaged CAN bus wiring or short to power/ground, poor grounds or low battery voltage.
U0545 — OBD2 code U0545 flags a problem with the vehicle network (CAN bus) communication (invalid data received from running board control module). Short, gentle driving to a shop is usually possible. Common culprits: corroded connectors, especially in wet areas, poor grounds or low battery voltage, aftermarket equipment interfering with the bus.
U0546 — OBD2 code U0546 flags a problem with the vehicle network (CAN bus) communication (invalid data received from entertainment control module front). Short, gentle driving to a shop is usually possible. Common culprits: aftermarket equipment interfering with the bus, corroded connectors, especially in wet areas, water ingress in harness junctions.
U0547 — OBD2 code U0547 flags a problem with the vehicle network (CAN bus) communication (invalid data received from "seat control module E"). Short, gentle driving to a shop is usually possible. Common culprits: damaged CAN bus wiring or short to power/ground, water ingress in harness junctions, a faulty module pulling the bus down.
U0548 — U0548 — Invalid Data Received From "Seat Control Module F". A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: a faulty module pulling the bus down, aftermarket equipment interfering with the bus, damaged CAN bus wiring or short to power/ground.
U0549 — Invalid Data Received From Remote Accessory Module (U0549): a vehicle network fault affecting the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Most often caused by aftermarket equipment interfering with the bus, poor grounds or low battery voltage, damaged CAN bus wiring or short to power/ground.
U054A — U054A — Invalid Data Received From Entertainment Control Module Rear "B". A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: a faulty module pulling the bus down, corroded connectors, especially in wet areas, poor grounds or low battery voltage.
U054B — U054B — Invalid Data Received From Interior Lighting Control Module. A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: corroded connectors, especially in wet areas, aftermarket equipment interfering with the bus, damaged CAN bus wiring or short to power/ground.
U0550 — U0550 — U0550 - Invalid Data Received From Active Safety Control Module 113. A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: damaged CAN bus wiring or short to power/ground, a faulty module pulling the bus down, poor grounds or low battery voltage.
U0551 — OBD2 code U0551 flags a problem with the vehicle network (CAN bus) communication (invalid data received from impact classification system module). Short, gentle driving to a shop is usually possible. Common culprits: corroded connectors, especially in wet areas, damaged CAN bus wiring or short to power/ground, a faulty module pulling the bus down.
U0552 — OBD2 code U0552 flags a problem with the vehicle network (CAN bus) communication (invalid data received from running board control module "B"). Short, gentle driving to a shop is usually possible. Common culprits: damaged CAN bus wiring or short to power/ground, corroded connectors, especially in wet areas, a faulty module pulling the bus down.
U0554 — U0554 — Invalid Data Received From Accessory Protocol Interface Module. A fault in the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Typical causes: aftermarket equipment interfering with the bus, damaged CAN bus wiring or short to power/ground, water ingress in harness junctions.
U0555 — OBD2 code U0555 flags a problem with the vehicle network (CAN bus) communication (invalid data received from remote start module). Short, gentle driving to a shop is usually possible. Common culprits: corroded connectors, especially in wet areas, water ingress in harness junctions, aftermarket equipment interfering with the bus.
U0557 — Invalid Data Received From Front Controls Interface Module "A" (U0557): a vehicle network fault affecting the vehicle network (CAN bus) communication. Short, gentle driving to a shop is usually possible. Most often caused by aftermarket equipment interfering with the bus, a faulty module pulling the bus down, corroded connectors, especially in wet areas.