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1999 STS
36 Posts
Discussion Starter · #1 · (Edited)
Ive been having excessive cranking/misfires and no tachometer for about 2 months now.After looking online on the possibilities of what it could be i decided to fix it myself.First I bought CKP sensors and the problem didn’t go away then I purchased an ICM from ebay and it Didn’t fix the code . I changed the connector C1 harness that clips to the ICM .It’s the one that only has 4 prongs on the connector even though there is a slot for 2 more. Didn’t fix the code 😥
Tried an aftermarket coil pack I had for awhile now .Didn’t work !!
After giving up I took the car to the Cadillac Dealership for a true diagnostic and a mechanic told me it was indeed the wire from my ckp sensor because he unplugged one and left the other in and literally there was no change in my car .So that’s when it clicked to me that the sensor he unplugged never worked since there was no change in the cars performance after it was disconnected .Dealership said it’ll be about $1000 for the wire to be fixed and a new engine front mount added 🤬🤬🤬
I immediately knew I was gonna fix it myself 😂 Took a drive from NY to PA to a pull-a-part and took the harness off of a 98 Deville and plugged it up to my car tonight after cleaning the wire of course and adding new loom/Electrical Tape

The pull-a-part place didn’t charge me for the harness either. WIN/WIN
Electrical wiring Computer hardware Cable Electronic engineering Wire

Instead of running the new wire behind the hot ass exhaust manifold again I ran it from the ICM ,past the air box,over the oil filter and right into the crankshaft sensors .

2002 F55 STS, 2014 Explorer XLT, F-150s
76,860 Posts
CranKshaft Position sensor
CaMshaft Position sensor
Ignition Control Module

Know that the ICM black ground cable has a big part in correct operation - clean. tight terminals.

From the sticky threads at the top of this Seville forum main page - timeless info in stickies -

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