Check Engine Light Codes — What They Mean
Your scanner — or the parts store — gave you a code. Here is what nobody tells you: a code is the start of a diagnosis, not the answer. The code names the system that reported a problem; it does not name the part that failed. Replacing the part in the code’s name is how people spend $700 and still have a check engine light.
These guides are written by the working mechanics at Autotech Mobile Mechanic and match our Code of the Week video series. Each one covers what the code means, what actually causes it, the symptoms you will feel, and the mistake that wastes the most money.
Code Guides
- P0300 — Random / Multiple Cylinder Misfire Detected
- P0420 — Catalyst System Efficiency Below Threshold (guide in production)
- P0171 — System Too Lean, Bank 1 (guide in production)
- P0455 — Evaporative Emission System Leak Detected, Large Leak (guide in production)
- U0100 — Lost Communication with ECM/PCM (guide in production)
- P0128 — Coolant Thermostat, Temperature Below Regulating Temperature (guide in production)
- P0562 — System Voltage Low (guide in production)
- C0035 — Left Front Wheel Speed Sensor (guide in production)
New guides are added as each Code of the Week episode is filmed.
Light On in Broward? We Come to You
Autotech Mobile Mechanic performs full computer diagnostics at your home or office across Broward County — Davie, Pembroke Pines, Plantation, Cooper City, Weston, Sunrise, Miramar, Hollywood, Coral Springs, and Fort Lauderdale. A diagnostic is $90 flat, and you get a firm quote before any repair begins. Call (954) 826-5523.