Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Is there an easy way to clear history codes like timming chain repairs from the pcm so when the history codes are looked up they are gone after repairs
History codes would get cleared during a normal code clear function. Permanent codes (Mode $0A) will only clear on their own after the problem is fixed, or if the ECM/PCM gets replaced.
