Why does the engine not crank or start?

ROBERT J. BEEMAN JR.

MEMBER
1998 CADILLAC STS
4.6L
V8
2WD
AUTOMATIC
105,000 MILES

I have replaced the following:

Starter
Alternator
Pullies
Tensioner
A/C compressor
Fuse box under the hood
Relays
Fuses

When I turn the key over everything comes on. No codes are being offered in the diagnosis. However, when pushed into the start position my dashboard goes blank. I don't want to have to replace the ignition if I don't have to. Also, curious if this is a case of needing to reprogram the keys, which would make super happy. That seems to be an easy process.

Also, the local pick and pull has an ignition that has all of the keys with it. The man that run the place said if I pulled the Body Control Module with it, I wouldn't have to do any reprograming at the dealership. Does that sound right?

5 Replies

KEN L

MASTER CERTIFIED MECHANIC
48,522 POSTS

Do you have a security light flashing when you try to crank it over? If not, it sounds like the dash integration module (BCM) is not working. Here is the location of the module so you can check it out and replace it. Here is the location and how to replace it in the diagrams below. Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.

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Friday, August 12th, 2022 AT 8:11 AM

ROBERT J. BEEMAN JR.

MEMBER
3 POSTS

As a matter of a fact the dash does go black when attempting to start. I have misplaced my fob and tried to use the valet key to start it.

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Friday, August 12th, 2022 AT 8:15 AM

KEN L

MASTER CERTIFIED MECHANIC
48,522 POSTS

Okay. We need to load test the battery or you may have a bad connection at the battery. These guides can help us see which problem you have; the battery test does not require equipment.

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

and

https://www.2carpros.com/articles/car-battery-load-test

Please run down these guides and report back.

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Friday, August 12th, 2022 AT 11:44 AM

ROBERT J. BEEMAN JR.

MEMBER
3 POSTS

Okay, so, the lights do not dim. I think it’s the security system. I have misplaced the fob and master key. All I have is my valet key. When I turn the valet key over the dash goes black.

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Monday, August 22nd, 2022 AT 5:03 PM

KEN L

MASTER CERTIFIED MECHANIC
48,522 POSTS

Okay, it sounds like a bad connection at the battery.

This guide can help you fix it:

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

Do all of the lights go you when you turn the key?