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6 comments
Active Contributor

Join Date: Jul 2009
Posts: 11

Jeep Grand Cherokee, 1998, Automatic Shutdown Device

12/13/2009 11:54 AM

Other than the relay, is there another part of this system, like a switch located on the car somewhere? I have looked at schematics and could not locate a switch or any thing that would tie into this. I did find a tie into the fuel pump and this relay on the schematic. But I'm no electrician or electronics type. I have trouble with the engine just cutting off. I have located a relay for the Automatic Shutdown Device in the power center under the hood. I felt this relay and it was very hot to the touch, burns your fingers when touched. Is this normal? I changed out the relay with a new one but no change. I also found that the relay for the fuel pump was warm to the touch. I get good fuel pressure and when I remove the pump relay while the car is running it shuts off slowly as the fuel pressure gage shows a decline in the pressure. When removing the automatic shutdown device relay the car just shuts off. This car has been rearended at one time. I don't know if this has anything to do with this problem. I know some cars have switches that shut the fuel pump down when ever they are hit or turn over in an accedent. This is my daughters car and she has a three month old. When she's on the road it just shuts down but in most cases starts right back up but in the other cases, she has to wait a few min. to restart. Any help would be great. Thanks guys.

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Pathfinder Tags: 1998 jeep grande cherokee automatic shutdown device engine shuts down
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Power-User

Join Date: Mar 2009
Location: United Kingdom
Posts: 320
Good Answers: 29
#1

Re: Jeep Grand Cherokee, 1998, Automatic Shutdown Device

12/13/2009 5:43 PM

"I have looked at schematics and could not locate a switch or any thing that would tie into this"
I think that you'll find that it is the "computer" that controls the relay coil.

"I have located a relay for the Automatic Shutdown Device in the power center under the hood. I felt this relay and it was very hot to the touch, burns your fingers when touched. Is this normal?"
NO ...It would indicate to me that you have an abnormally high load/amps running through your relay contacts.

Tracing this excessive load could be a pain.

Good luck

Here's a description of an ASD setup that may help.
http://www.allpar.com/fix/codes/sensors/auto-shutdown.html

Regards Woody

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Guru
United States - Member - Member Hobbies - DIY Welding - New Member

Join Date: Mar 2008
Location: Southeast US of A
Posts: 532
Good Answers: 50
#2

Re: Jeep Grand Cherokee, 1998, Automatic Shutdown Device

12/13/2009 11:28 PM

I would suggest you take your vehicle to an experienced Chrysler technician for diagnosis.

These vehicles use a design philosophy pretty much unique to Chrysler vehicles (in reference to engine electronic controls) and can be difficult to inspect without experience.

In my experience, most DIYers are unable to repair these, or spend hundreds or thousands of dollars by doing it themselves; oftentimes without solving the problem.

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Commentator

Join Date: Aug 2009
Location: Leavenworth, Washington
Posts: 77
Good Answers: 13
#3

Re: Jeep Grand Cherokee, 1998, Automatic Shutdown Device

12/19/2009 11:58 PM

The jeep uses and engine management system that is built by Chrysler. The ASD relay (automatic shutdown relay) is controlled by the PCM. The pcm needs to see a CKP signal (crankshaft position sensor) & a CMP (camshaft position sensor) signal in the proper sync before the ASD relay will be turned on by the pcm. When you first turn the key on, the ASD relay is closed for one second to prime the fuel system, then remains open until the pcm sees the valid signal from the CKP & the CMP, in proper sync with each other, then the ASD relay contacts are closed, and the ignition coils, the fuel injectors & the oxygen sensors receive their power. If you are having a problem with the engine not starting, or the engine dying, the first place to start is with the ASD relay & the CKP & CMP sensors. To properly test these, a two channel lab scope is needed so that the signals can be tested for proper shape, and synchronisation.

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Active Contributor

Join Date: Jul 2009
Posts: 11
#5
In reply to #3

Re: Jeep Grand Cherokee, 1998, Automatic Shutdown Device

12/24/2009 2:37 PM

What I need is a schematic of the ignition switch and all the circuits going to and from the switch and to the power center. My Haynes Manual is no good. Doesn't show enough. Please see the thread below. I'm new at this. Thanks.

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Active Contributor

Join Date: Jul 2009
Posts: 11
#4

Re: Jeep Grand Cherokee, 1998, Automatic Shutdown Device

12/23/2009 4:51 PM

Thanks for the info. I had already replaced both of these sensors and the relay. Now the problem is getting worse. I don't know if this is related, but now the gage cluster turns off while driving. All the dials turn off. No tac, no speed, no oil, no amp, no gas, no oil but have dash lights and turn signal indicators. Totally baffling no power windows, but get this the windows work when the ingition switch is in acc mode. The gages return if you turn the starter switch to the start mode and let go back to run, but after about 5 seconds all the gages return to 0 and no longer respond. I replaced the ingition switch and traced every wire from the power center to the ignition switch and did not find any loose connections or cut/frayed wires and no blown fuses. I am working with a Haynes manual and they don't have very detailed schematics. I can't afford to pay a pro at $125 and hour for tracing problems.

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Active Contributor

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Posts: 11
#6

Re: Jeep Grand Cherokee, 1998, Automatic Shutdown Device

01/04/2010 10:54 PM

Found out what the problems were. There were two. One was the gage cluster and the other was the car shutting off. The gage cluster had a bad connection where the cluster plugged in to the dash receptacle. Removed the receptacle from it's mount and straightened out the wires and pushed them into the plug from behind and instant repair. No more gage problems and no more power window problems. The shut off of the motor was the computer. Bought a used one at the local Pick and Pull and replaced the existing computer with this one and no more problems with the engine shutting down. It's always the simple things. Thanks for your input guys.

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