I have a 1999 Buick Lesabre Custom that I've had for about a year now and about a month or two ago the check engine light came on and it's been flashing. I got it diagnosed and it said spark plugs and wires. I had those replaced and nothing changed. Then, tried to replace the ignition coil for the 1 and 4 wires and still no changes. Those two have no power going to them at all. I can still drive my car but it shakes very badly as the cylinders misfire, and the gas mileage is horrible. I'm putting off getting an oil change as the car is putting gas into my engine oil. My mechanic believes it's the ignition module itself. I did have the distributor cap looked at and it seemed fine. I'm hoping for some advice before I buy the module and possibly waste money. Thank you in advance!

  • Welcome to Motor Vehicle Maintenance & Repair! Your car doesn't have a distributor cap, so don't know what you were checking, but it wasn't that. Have you checked your fuses? I don't remember on the 3.8L V6, but it may have separate fuses for each coil (there should be three, two pole coils). When you say "those two have no power going to them at all", are you saying you're not getting any spark coming out of them? If so, have you checked to ensure the ground is good and that there is actually power going to them? I believe there should be three wires to each: power; ground; trigger. – Pᴀᴜʟsᴛᴇʀ2 Sep 9 '17 at 4:31
  • @Pᴀᴜʟsᴛᴇʀ2 On those engines the ignition control module has two terminals for the coils. The coils sit on the ICM. OP should have the 1/4 signal from the PCM checked as well as the CKP signal to the ICM. On these engines the CKP sends a signal to the ICM, which is sent to the PCM. Then back to the ICM to fire a coil pack. ICMs going bad are pretty common. – Ben Sep 9 '17 at 18:49
  • @Ben - TY, Kind Sir. I always appreciate the assists. – Pᴀᴜʟsᴛᴇʀ2 Sep 9 '17 at 18:52

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