Buick LeSabre Never-ending Ignition Coil Problems

Hey guys - I’m sure you hear this all the time (I bet they even precede it with something like I just did), but I’m not exactly car savvy, so I’m looking for help.

My 2004 Buick LeSabre will not stop burning out ignition module coils. I have begun to accept that every 3 months or so it will die on the road, which has happened about four/five times now I think. I need to avoid this if possible.

I have brought it to three shops and apart from replacing either the whole module or all the coils no one can fix what is actually causing this. I am so fed up with it that I almost want to drive it over a cliff (dummy inside, not me).

Are there any things I should check for that might help me out on this? I can supply any further info needed, including pictures.

I would make sure your plug wires are good, I would also install factory Delco plugs. Other than that ensure the grounds and power sources are in good condition including the pin fit at the coil pack. The other consideration is the quality of parts being installed, I have seen cheap coils fail in short periods of time for no reason at all.

I would have to agree with @Steve76 on this. If your plug wires are bad the high voltage has no where to go and may arc inside the coil wiping it out, which in turn may wipe out the module.

The same holds true for the plugs if they are gapped to wide or are otherwise defective.

According to each of the shops I’ve brought it to they’ve all stated the wiring was solid and there wasn’t a ground issue. I’m not sure if this matters, but I have had autostart work done on the car - is there any chance this type of thing can cause any type of charge issue? That sounds like a huge broad question - sorry about that!

Also, to add, the spark plugs too have been replaced previously.

I guess you mean by autostart the engine shuts off when you stop and starts when you depress the accelerator. Why not disconnect the feature for a while to see if it is a problem? I was lead to believe that autostart was not a retrofit item.

“… replacing either the whole module or all the coils …”

How often were the coils and module replaced together? A failing module can degrade the coils and vice versa.

Just my 2 cents and I could be dead wrong, but I suspect some misdiagnosis of the problem which may not even be related to the coils.

It’s stated that the coils are “burning out”. How in the world has that been determined.

To make matters worse, this is stated to be a 4 or 5 time event with 3 different shops involved.
That muddies the water even more.

The problem might be with the ECM. (Engine Control Module)

Here’s how ignition system works.

When you’re starting the engine, the ECM allows full battery voltage to the Ignition Control Module at the voltage control terminal. This insures there’s a hot enough spark when starting the engine when cold. Once the engine starts, and the ignition switch moves to the run position, the ECM is suppose to command that the ICM reduce the voltage to the coils when the charging system comes on line.

If the ECM fails to command the ICM to reduce the voltage to the coils, you’re operating the coils off charging system voltage. And that will burn out coils in a short time.


The shops stated the wiring was solid. Were they referring to the spark plug wires or the wiring leading to the ignition module? You really can’t tell if the spark plug wires are good just by looking at them. If they’re the originals they are eleven years old. They break down with time.

GM stamps the cylinder number on each plug wire. If you see numbers on them they may be original. If so I would change them.

Is the auto start system something you can have disabled for diagnosis? If it is easy to do I would disconnect it for a few months and see if the problem is resolved, aftermarket accessories can create strange issues. Did this problem occur after the auto start system was installed?

I think I’m with the others. I do know that on my Olds, I was advised to change the plug wires along with the coils and use only GM wires. I’d change the wires and also I think Tester may be correct. At this point I’d put in the new (or used) ECM to cover all the bases.

Another thing you might have checked out is the alternator. Make sure that the DC voltage doesn’t exceed 14.8 volts and the AC ripple voltage is less than .1 volt AC while the engine is running around 1,500 RPM.

If the module requires a heatsink compond for proper cooling make sure that is applied correctly. Thinly and evenly.

Has the ICM ever been replaced?

Three dual tower ignition coils are mounted to the ICM, and are serviced individually. The ICM performs the following functions:

•The ICM supplies a power and low reference circuit to the CMP and CKP sensors.
•The ICM determines the correct direction of the crankshaft rotation, and cuts spark and fuel delivery to prevent damage from backfiring if reverse rotation is detected.
•The ICM determines the correct coil triggering sequence, based on how many 18 X ON-OFF pulses occur during a sync pulse. This coil sequencing occurs at start-up, and is remembered by the ICM. After the engine is running, the ICM will continue to trigger the coils without the CKP sync pulse.
•The ICM inputs 18 X and 3 X reference signals to the PCM.
•The 3 X reference signal is also known as the low resolution engine speed signal. This signal is generated by the ICM using an internal divide-by-six circuit. This circuit divides the 18 X signal pulses by 6. This divider circuit will not begin operation without a sync pulse present at start-up, and without 18 X and 3 X reference signals no fuel injection will occur.

If the coils keep going out, here’s the likely possibilities

  1. The replacement coils are no good from the start, cheaply made aftermarket parts or something. Solution: Buy OEM replacement coils from Buick.
  2. The voltage is too high at the coil. As mentioned above, the voltage is supposed to be higher when starting the engine, then lower when the engine is running. Also, there’s supposed to be enough resistance in the plug wires to properly limit the voltage. Solution: Ask the tech to measure the applied voltage and the wire resistance and compare to what is spec’d by the manufacturer.
  3. The coils are overheating b/c of a heat sink or mounting problem. Solution: Make sure everything is mounted, using the correct fastener torque, exactly the way the car came from the manufacturer.
  4. The wrong spark plugs. Solution: Make sure the plugs have the exact same part number as one recommended in the owner’s manual. Edit: And make sure the plugs are correctly gapped. Too wide of plug gap can cause this.

LJ2 Did you find a solution? I have same problem.

A remote Start cannot cause this…The Remote Start system simply uses all the wires that the ignition switch uses to start the vehicle…Its as if you had an assistant start the car for you…There is no difference whatsoever.

The information Tester posted is very interesting. I wasnt aware of a voltage changeover. If this is true for this vehicle I would absolutely look into that.

Aside from this I was going to suggest RUNNING YOUR OWN GROUND…from the coil pack to a solid KNOWN good ground. It certainly cannot HURT anything…and very well may cure the issue.
The QUALITY of the replacement parts is absolutely of concern and a valid question…If the new coil pack is made in CHINA…THis is basically Par for the course. I would install a known good coil pack from the Junkyard before installing ANYTHING made in China on my engine. A used OEM coil pack will be FAR BETTER QUALITY than any part made with “CHINESEIUM” I hate to say that and make such a distinction…but Dems the facts… I stay FAR FAR AWAY from Chineseium


Again . . . somebody resurrected a thread which was dead for 4 months

Why is resurrecting an older thread an issue? If the information is valid… I’m very grateful to have found this. I’m being gifted a not-running 04 LeSabre. Needs Plugs, wires, coils, and possibly an Ignition control module. So I Binged ignition control module for 04 Buick. Ended up here. Seems pretty fortuitous to me! I’ll take all the help I can get! :grin: I’m 55, a cancer fighter, and will probably be gapping be gapping the damn plugs myself. Settle down guys. I know how, and thanks to this article, I know to make sure to keep the gap tight. I also know that 2 of the coils are questionable. But reading through this that now makes a heck of a lot more sense than before. Tester’ shout out to you, your description of the current from ignition through leveling off helped immensely. Thanks guys!!

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BTW I’m female :blush: