Cadillac Seville / Cadillac Eldorado Forum Discussion, What Do These Codes Mean??? in Past Cadillac Vehicle Discussion; I got 2 codes i have no idea what they mean
PCM P0603 - Control Module Long Term Memory Reset
the headlight is a history and they are working fine.. but i didnt touch the battery!! what does the P0603 mean exactly? bad battery? bad cords/cables?
P0603 is An intermittent loss of power or ground to the PCM and it caused a PCM reset. Check all power and grounds to the PCM if they check OK the PCM could be going bad. At this time just clear codes, check your battery connections and see it the DTC returns, do not replace the PCM yet.