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Old 04-10-2012, 04:20 PM   #1
Join Date: Apr 2012
Posts: 2
Immobilizer problem

88 jeep 99 motor swap (fuel injected) starts and "dies" a few seconds later. it sounds like its a fuel problem but the pressure is right at 51 the whole time. the guy i bought it from did the swap on his own and there is a rats nest of wires below my dash.. i can see where the immobilizer wires are hooked up and spliced into the wires that comeout of the obd plug in... im wondering if i can mypass this stupid thing or should i fix it... the only problem with that is i live in bfe in arizona and have nothing close to tow it to ....thanks Tim

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Old 04-10-2012, 04:38 PM   #2
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Location: Lehi, UT
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Originally Posted by Timbuk View Post
i can see where the immobilizer wires are hooked up and spliced into the wires that comeout of the obd plug in... im wondering if i can mypass this stupid thing or should i fix it.
I really don't think it is something you can bypass, at least not in the traditional sense of the term.

Here is a summary of how the Sentry Key system operates: each key has an internal chip which is programmed with a particular code. The engine controller has this code number written into its memory. Every time the engine starts, the computer sends an ID request to the key. When the ID comes back to the controller, it checks for a match. If the key is valid, everything continues as normal. If there is a discrepancy, the engine is turned off.

I remember 10 or 11 years ago when a customer bought a then-new Chrysler 300M and wanted an aftermarket remote start system installed in it. The installer came out and added the system like normal, only to discover the Sentry Key system would shut down the car each time you remote started it. He spent an entire Saturday afternoon trying to find a way to bypass it, all to no avail. The customer was insistent on having their remote start, so the installer did the only thing that worked--he had us cut an extra Sentry Key and program it, then he duct taped it to the metal steering column underneath the plastic shroud. Now that the computer could "see" a valid key, the remote start worked perfectly. (Of course, this completely defeated the anti-theft benefit of the system.)

You may need to do something similar.

Dempsey Bowling
My fleet: 91 Miata, 98 Wrangler Sport, 01 Suburban 8.1L, 14 Impreza, 03 Protege
Jeep mods: 4" longarm + 1" BL, 35" KM2s, 4.56s with dual ARBs... and lots of scratched armor
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Old 04-10-2012, 05:52 PM   #3
Join Date: Apr 2012
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the grey key i have is an uncut key that was zip tied to the black immobilizer box. so im guessing its the same way that the 300m had to be hooked up... now the hard part is going to be looking for a diagram on the immobilizer i have installed. Thank you for that i was thinking i could just back track the wires and take em out...
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immobilizer , start and stop , starting problems

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