What is the correct sequence for reading and clearing engine fault codes?
3 Answers
Engine fault codes must be cleared in the following sequence: First, read the static codes (KOEO mode). If the system does not output a normal fault code "11" after reading the static codes, then proceed to read the dynamic codes (KOER mode). Otherwise, it may lead to distorted fault readings and misdiagnosis during troubleshooting. Note that before reading dynamic codes, the static codes should generally be cleared first. An engine is a machine that converts other forms of energy into mechanical energy, originating in the UK. It can refer to either a power generation device or the entire machine including the power unit (such as gasoline engines, aircraft engines). Types of engines include internal combustion engines (e.g., gasoline engines), external combustion engines (e.g., Stirling engines, steam engines), and electric motors.
As a mechanic who works with engines every day, I must say that dealing with fault codes isn't just about clearing them randomly. The correct procedure for reading codes is: First, connect the diagnostic tool to read all fault codes—don't rush to clear them. Record each code and its description one by one. Then, consult the repair manual based on the fault codes. For example, P0171 indicates a lean fuel mixture, so focus on checking the intake or fuel system. After fixing the issue, conduct a five-minute road test to ensure the fault doesn't reappear before clearing the codes. Finally, recheck the system for any hidden faults; otherwise, the warning light might come back on after a couple of days, wasting all your effort. The key is to address the root cause—many beginners simply clear the codes, only to worsen the engine issues.
We car modifiers all know that clearing fault codes must follow the procedure: First, start the diagnostic tool to read the original codes while checking freeze frame data, recording status like RPM and coolant temperature. Second, don't rush to clear - analyze whether the cause affects safety, like how driving with a catalytic converter fault can directly damage the engine. Third, confirm repairs are correct before clearing codes, then perform idle testing and re-scan to ensure system reset. I learned the hard way - once didn't recheck before highway driving when the ABS fault suddenly reappeared, super dangerous. The whole process takes just 30 minutes.
