How do you troubleshoot the P0302 code?
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Cadillac Seville / Cadillac Eldorado Forum Discussion, How do you troubleshoot the P0302 code? in Past Cadillac Vehicle Discussion; Of course this happens on the first day of school. 2001 Cadillac Seville SLS. The car stutters on acceleration. How ...
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    rydamee's Avatar
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    How do you troubleshoot the P0302 code?

    Of course this happens on the first day of school. 2001 Cadillac Seville SLS. The car stutters on acceleration. How do I decipher whether it's the coil pack, fuel injector or otherwise? Don't know if this helps with my question, but normally when the engine is on, my scanner shows short & long term fuel trim for both banks. It's reading 0% on all four trim banks now, normally I get actual values, not zeros. Car runs & drives, you can feel the stutter though. How do I pinpoint the issue be it coil or plug or injector? Thanks gentlemen...

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    basscatt's Avatar
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    Re: How do you troubleshoot the P0302 code?

    Quote Originally Posted by rydamee View Post
    Of course this happens on the first day of school. 2001 Cadillac Seville SLS. The car stutters on acceleration. How do I decipher whether it's the coil pack, fuel injector or otherwise? Don't know if this helps with my question, but normally when the engine is on, my scanner shows short & long term fuel trim for both banks. It's reading 0% on all four trim banks now, normally I get actual values, not zeros. Car runs & drives, you can feel the stutter though. How do I pinpoint the issue be it coil or plug or injector? Thanks gentlemen...
    ------------------------
    KISS - Keep It Simple - Stupid

    use a stethoscope - or a long screwdriver - or similar - and listen to the injector -
    IF the injector is working properly - you will hear a "clicking" -
    one click for each time it is suppose to deliver a shot of gas -
    no click = a dead injector -

    but 95% of the time - it is the coil cassette -

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    rydamee's Avatar
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    Re: How do you troubleshoot the P0302 code?

    Checked for clicking, it's there. So I guess I need to head out to the salvage yards to see if I can band-aid it until I get a chance to buy a new coil cassette. Thanks bass. Will I incur any engine damage by driving the car? Watching the engine actually shaking with the hood up is extremely disconcerting being this is a luxury car & not a '69 ZL1...

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    Re: How do you troubleshoot the P0302 code?

    Quote Originally Posted by rydamee View Post
    Checked for clicking, it's there. So I guess I need to head out to the salvage yards to see if I can band-aid it until I get a chance to buy a new coil cassette. Thanks bass. Will I incur any engine damage by driving the car? Watching the engine actually shaking with the hood up is extremely disconcerting being this is a luxury car & not a '69 ZL1...
    ---------------------------------
    Will I incur any engine damage by driving the car?
    ENGINE damage - NO -
    but keep in mind -

    IF the injector IS delivering gas when it should - and I believe it is -
    and IF the coil is NOT delivering spark - and I believe it is not -

    you are dumping raw fuel into the cat -
    and that means the cat will be running hotter than "normal"

    drive in that condition too long - and you will damage the cat -

    I guess I need to head out to the salvage yards
    to see if I can band-aid it
    until I get a chance to buy a new coil cassette


    there is nothing wrong with a used coil cassette -
    for the most part - they are very reliable -

    $25 to $50 used from the "MAN'S MALL" -
    $275+ for new -

    a good used one would be just fine -
    -----------

    all coil cassettes are the same -
    the only difference between the front - gray -
    and rear - black - is strictly the color -

    and the cassettes from all Cadillac models are the same -
    Deville - Seville - Eldo - also the Olds Aurora uses the same cassette -

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    Re: How do you troubleshoot the P0302 code?

    Thanks bass. This site has just a plethora of knowledge, I tell you whut... lol

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    MoistCabbage's Avatar
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    How many miles on the car? Plugs and boots are due by 100K, and the car is 12 years old on top of that.

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    Re: How do you troubleshoot the P0302 code?

    Just got back from the salvage yard. Got a rear module cuz of course all the ones that's easy to get to are gone. Installed it on my front bank in less than 5min & she's running smooth again. Thanks bass!!! Moist, she has 107k on her. When I get enough loot I'll replace them both with new units. She had the 100k service done at the Caddy dealer right before I bought it, I was standing next to the previous owner shaking my head cuz he got a radiator(didn't need), starter & battery along with the 100k service. It was free new parts for me so I didn't stop him. Lol. Imagine that receipt. Lol...

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    Re: How do you troubleshoot the P0302 code?

    Quote Originally Posted by rydamee View Post
    When I get enough loot I'll replace them both with new units.
    If it ain't broke, don't fix it. Those ignition cassettes are pretty reliable. Considering the cost of new units, I would not hesitate to install a used one and probably will if mine ever fail.

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    Re: How do you troubleshoot the P0302 code?

    Really Ranger? I mean, even though there are no moving parts, you'd still be reluctant to replace two 100k coils? Tell me then, what other parts on the vehicle with over 100k miles would you have the confidence to hold on to? For future reference. I know your word is good. It's just, to me, 100k means time for new parts so I can get 100k more miles out of her. I'm listening though so speak on it sir...

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    Re: How do you troubleshoot the P0302 code?

    Hard to start naming parts off the top of my head, but I just picked up a nice clean 134K SLS for my daughter and I do not intend on replacing the ignition cassettes until (and if) they fail. I do plan on flushing the brake lines and changing coolant, but where do you stop when replacing 100K parts? That could get very costly, but the choice is yours.

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    rydamee's Avatar
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    Re: How do you troubleshoot the P0302 code?

    Well, truthfully, I feel the entire suspension should be overhauled at 100k, bushings & struts & shocks. That HAS to be done on a vehicle this old & this heavy. Under the hood though, usually any moving part that works, will be there til that part dies, 100k or not... Thanks for the help gents. My woman thinks I'm a genius with my scanner that works through my phone. She's not computer literate so I'll take the credit for y'all... Sweet...

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    100K is not a magic number that causes every part of the car to fail. Why not 80K? Why not 120K ? Why not 117K?...

    A coil either works, or it doesn't. It could fail at 10 miles, 100K, 500K, or never.

    100K means time for new parts? Following that logic, you might as well replace EVERY SINGLE wear item, mechanical part, and electrical part, or buy a new car.

    Are you replacing the ELC compressor? The fuel pump? The trunk latch?

    Save your money for if and when something happens, unless a part is showing signs of wear, or performing marginally.

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    Re: How do you troubleshoot the P0302 code?

    Moist, I don't know about your driving climate or conditions, but here in sunny SoCal, we have these things called freeways. They were designed for 55mph+, we use ours at 5mph 70% of the day. 120 miles a day at those speeds will cause premature wear on certain parts, right? If the vehicle was engineered for said conditions is one thing, but it wasn't. Constant heat soak & little airflow doesn't instill confidence in parts lasting past 100k. Not 150, not 170, not 200k but 100k. I ride bikes so I'm into preventive maintenance. I won't ride a "new" bike unless it has after market Dunlops, rotors, brake hoses, pads,chain & grips. Why? Cuz they didn't design the stock parts for the conditions I'll expose them to. Plus, a new part is a new warranty in my eyes. Post #11 needs to be re-read though...

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    Re: How do you troubleshoot the P0302 code?

    Quote Originally Posted by MoistCabbage View Post
    How many miles on the car? Plugs and boots are due by 100K, and the car is 12 years old on top of that.
    I agree plugs and boots need to be done if they have not in 100K make a big diffrence I had simular issues and plug and wires fixed it.

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    Yaemish is offline Cadillac Owners Connoisseur
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    Re: How do you troubleshoot the P0302 code?

    I had done my plugs but kept the boots. I was getting a code that indicated it may be the coil pack. Even though I disassembled and cleaned all the old boots once the codes appeared, it didn't help. New boots fixed it.

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