The car starts right up and then shuts itself off?

Tiny
DOBSKY72
  • MEMBER
  • 2000 OLDSMOBILE INTRIGUE
  • 3.5L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 214,000 MILES
It has new starter and ignition switch. When key is in on position the security light comes on and stays on, no blinking. While ignition is on, I can start car at relay with plastic cover off by squeezing the relay. The car starts right up and then shuts itself off within a second or two. So I figured it had something to do with the alarm theft system so I tried a bypass passkey and relearning signal with 30min process but security light never went off after 10min and just stays on. Please help.
Tuesday, September 2nd, 2025 AT 2:26 PM

7 Replies

Tiny
KEN L
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The security system will not make the engine not crank over, they simply cut the fuel off to make the engine not run. Did you try cranking it in neutral? If it starts the gear range sensor is bad (neutral safety switch). Here is a video to help, also you need to check the PCM BCM U/H fuse in the fuse panel inside the car and the IGN2 50 amp fuse under the hood.

https://www.youtube.com/watch?v=6YRW8fyNudY

Please go over this guide and check the fuses get back to us :)
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Wednesday, September 3rd, 2025 AT 9:08 AM
Tiny
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I tried what was suggested and to add to the response. The car shuts down after it's started from the crank relay, which is the security system. So then is Ken suggesting that I have two separate issues
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Monday, September 15th, 2025 AT 8:23 AM
Tiny
KEN L
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So does the security light flash when you try to start it If so I would do a hard system reboot, this video can show you how.

https://www.youtube.com/watch?v=INiDRO5A5MY

Let us know how it goes
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Monday, September 15th, 2025 AT 8:25 AM
Tiny
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The security light is constant no flashing
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Tuesday, September 16th, 2025 AT 5:55 AM
Tiny
KEN L
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This means the security system on disabled. So is it the cranking you are having an issue with or the engine running? Can you please upload a short video of what is going on in your response?
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Tuesday, September 16th, 2025 AT 10:03 AM
Tiny
DOBSKY72
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I believe the video says it all
Video (Click to make bigger)
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Tuesday, September 16th, 2025 AT 1:08 PM
Tiny
KEN L
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Thank you, I seem like the fuel pump is not working or you are not of gas or the car has old gas in it. I would try starting fluid to see if you can keep the engine running. This video will show you how.

https://www.youtube.com/watch?v=lXLJbuAZ4CE&t

The cars like it is in many pieces? Are all of the electrical plugs back together?

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Tuesday, September 16th, 2025 AT 4:47 PM

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