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!
2011 Lexus Is250 111k miles my wifes daily. Check engine light came on the other day for you guessed it a P0301. Decided to check current ramp of coil and found it to be shorted exactly like the others. Waveform shows shorted secondary winding. This is the 3rd ignition coil to fail in the same manner since October of last year. The last time i changed a coil was over the summer as well as the spark plugs to rule out cause of premature failure (in my opinion). What would cause ignition coils to keep shorting? Is this the cause of an underlying problem? The car runs fine otherwise. What should i look for? Thank you guys for any help.
Once you put a new one in have you checked ignition control module/pcm to see if it is firing it more than it should (shorted coil driver) or wiring to see if it is shorting to ground? This typically would cause your issue.
Obvious questions:
(1) Is it the replaement coil that failed ?
(2) Did you check the spark plug gaps before fitting ?
(3) Is failure on the same cylinder no 1 ?
(4) Was it an official Toyita/Lexus part ?
Shorts in the secondary on plug top coils are usually down to to excess KV (worn plugs) or coil has a manufacturing defect or is physically damaged.
Keep in mind P030x misfire codes don't always point to the correct cylinder.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Its been a different coil each time I've gotten a misfire code. After the 2nd coil failure I replaced all spark plugs. I'm just wondering what would cause coils to fail besides spark plugs.
Topic Author
