# 1991 Cadillac Eldorado - Starts then dies

**URL:** <https://community.cartalk.com/t/1991-cadillac-eldorado-starts-then-dies/200596>\
**Category:** Maintenance/Repairs\
**Tags:** cadillac\
**Created:** [June 11, 2025, 12:51am UTC](https://community.cartalk.com/t/1991-cadillac-eldorado-starts-then-dies/200596 "2025-06-11T00:51:31Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Ryan29](https://avatars.discourse-cdn.com/v4/letter/r/b4bc9f/32.png) [@Ryan29](https://community.cartalk.com/u/Ryan29)\
**Post date:** [June 11, 2025, 12:51am UTC](https://community.cartalk.com/t/1991-cadillac-eldorado-starts-then-dies/200596/1 "2025-06-11T00:51:31Z")

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My caddy starts up then dies its says cautiously theft issue starting disabled

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**Author:** ![weekend-warrior](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/weekend-warrior/32/26122_2.png) [@weekend-warrior](https://community.cartalk.com/u/weekend-warrior)\
**Post date:** [June 11, 2025, 2:20am UTC](https://community.cartalk.com/t/1991-cadillac-eldorado-starts-then-dies/200596/2 "2025-06-11T02:20:04Z")

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You probably have a problem with your VATS (Vehicle Anti-Theft System)  
GM vehicles had problems with this. there is a way to bypass the VATS system. there are plenty of videos online showing you how. just be aware you won’t have a working alarm system.

**The VATS system:** The GM VATS (Vehicle Anti-Theft System) system uses a black pellet in the metal part of the ignition key. The VATS decoder send a ‘key OK’ signal to the PCM/ECM when the proper key is detected. Without this signal, the fuel injectors will shut down within the first 3 seconds.

 ![VATS key](https://global.discourse-cdn.com/cartalk/original/3X/e/2/e291ce3af1db4b2197615f5fb6b931b6dc3f472f.jpeg "VATS key")

**The VATS problem:** The VATS system may become problematic with age. Increased wear, and higher resistance due to dust and corrosion can lead to ignition key readings that prevent the vehicle from Starting

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**Author:** ![hsn\_19](https://avatars.discourse-cdn.com/v4/letter/h/7bcc69/32.png) [@hsn\_19](https://community.cartalk.com/u/hsn_19)\
**Post date:** [June 22, 2025, 1:05pm UTC](https://community.cartalk.com/t/1991-cadillac-eldorado-starts-then-dies/200596/3 "2025-06-22T13:05:45Z")

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Could be the VATS anti-theft system. Try a spare key or check the key resistor. You may need to bypass or fix the system.

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**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [June 22, 2025, 2:33pm UTC](https://community.cartalk.com/t/1991-cadillac-eldorado-starts-then-dies/200596/4 "2025-06-22T14:33:47Z")

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See if this solves the problem.

> **[GM\_VATS\_RELEARN\_PROCEDURE.pdf](https://pcmperformance.com/programming_files/GM_VATS_RELEARN_PROCEDURE.pdf)**
>
> 397.21 KB

Tester