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misfiring out of the blue.


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I will look into that. I now have a used spare that #8 is not firing. Thanks. runs good. light went out during third trip today

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Strange problem. I had a failing ignition coil on my STS 7-8 years ago. Never had a problem since. I would look for a faulty PCM-wiring. The PCM itself rarely fails.

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I tend to think it is not a bad wire or plug because with the old coil installed I did a thorough wiggle test and nothing changed.

When I installed the new coil it ran perfect and still did while performing the wiggle test again.

I thought about getting the repair pigtail anyhow just to have

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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barcz01 - as you know, coils fail more often than modules. You can replace just the coils, but I believe that if you buy the coils from a dealer the module comes with them. Since the module is available separately (see barcz01's part number), I suppose that the coils are available separately, too. But I haven't heard of anyone replacing just the coils.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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barcz01 - as you know, coils fail more often than modules. You can replace just the coils, but I believe that if you buy the coils from a dealer the module comes with them. Since the module is available separately (see barcz01's part number), I suppose that the coils are available separately, too. But I haven't heard of anyone replacing just the coils.

Replacing the individual coils is not possible on this vintage of cars. The coils are integral to the "cassette" on the 2000-2003 cars. There is a cassette for the front bank of cylinders and one for the rear bank.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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The cassette includes coils and a module. The module is replaceable in the cassette, apparently.

Looking at the schematic in the 2002 FSM, it appears that the modules take spark signals, with ignition timing, from the PCM and perform the function of driving the coil primary windings. They are probably "amplifiers" that perform the function of points-and-condenser in the classical Kettering ignition (applying 12 Volts across the coil primary and interrupting the current to drive the spark when the PCM signal comes in), except that there is one per spark plug, of course; this is the HEI ignition coil driver type.

The wire colors from the PCM to the modules that fire each of the plugs is:

  • PPL: IC 1
  • LT BLU: IC 3
  • DK GRN: IC 5
  • RED: IC 7
  • RED/WHT: IC 2
  • DK GRN/WHT: IC 4
  • LT BLU/WHT: IC 6
  • PPL/WHT: IC 8

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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The coil pack module and ICM are able to be separated but the coil pack unit comes with a new ICM installed. The coil is very likely what failed on the units on me.

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Well great news. Car runs great. If it werent for my shake in the front it would run and ride perfect.

It runs so smooth you cannot feel a thing

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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:bluesbrothers:

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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I am going to order the other coil module and replace it in spring when Ido the rear plugs. Then I will have a spare also.

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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The front coils module is silver and the rear one is black; they are electrically identical and they are interchangeable. The silver finish makes the front module a few dollars more expensive. If I were to order one for a spare, I would order the front one because a silver module on the rear will look OK but a black one on the front would look terrible.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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I am going to order the black one, but technically with what this car looks like I dont think it would even matter. If it was my Seville then I would make sure it is right

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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