2003 jeep GC dies while driving and won't restart because of sentry key immobilizer - JeepForum.com
LinkBack Thread Tools
post #1 of 9 Old 01-07-2010, 10:29 PM Thread Starter
Registered User
Join Date: Feb 2007
Location: CT
Posts: 37
2003 jeep GC dies while driving and won't restart because of sentry key immobilizer

hello again,
have couple other threads regarding this problem, jeep dies while driving, will sputter and die and you have to coast to a stop.
typically it would start right back up, but now tonight after a few minutes of driving it died and would not restart. When turning the key to run, the dash board illuminates, but no gauges register, the gas gauge stays below E and the volt gauge does not show any voltage, and the yellow key with a slash through it in the upper right is illuminated.
I also plugged 2 code scanners in at this time and they report NO LINK.
engine will crank and crank but not fire, headlights and radio and heater all work.
If i wait 5+ minutes, i turn the key to run and if the gas gauge registers and the volt gauge shows something, then i'll also get the code scanner to link up and work, the engine will start right up and i can take off and go a mile till it dies again and repeat the procedure.

I have replaced the crank sensor, and have swapped fuel pump relays.
I get no codes thrown, and never have.
I just got a fuel pressure gauge but haven't used it yet,
but if i had to guess it seems like the alarm system is tripping while driving cutting power to the fuel pump until engine dies. Is this possible?

It's been suggested that the fuel pump is the problem, and i would have no problem believing that if the sentry key indicator light didn't trip and prevent me from restarting. There's been many times that i could start it right back up, but now it seems like every time it dies i have to wait about 2 to 5 minutes before i can restart. Or can the failing fuel pump assembly- the fuel sending unit and not necessarily the pump, be bad and cause this?

will try idling in the driveway tomorrow and see if it's a time/heat thing with fuel pump crapping out, so far it's only happened when driving and it seems like if i find rough road that definitely causes it to die.

does the ignition key have any type of chip or resistor in it? mine look plain. my keys for my chevy have a resistor chip in it. could the ignition key or cylinder be the problem?

2003 Jeep Grand Cherokee Laredo
4.0L, 4wd selec-trac, stock
ron7000 is offline  
Sponsored Links
post #2 of 9 Old 01-07-2010, 10:48 PM Thread Starter
Registered User
Join Date: Feb 2007
Location: CT
Posts: 37
reading the owner's manual,
-if SKIS illuminates and flashes immediately after the ignition switch is turned on, an invalid key was used-
this has never happened.

-if the SKIS comes on during normal vehicle operation (it has been running for longer than 10 seconds) a fault has been detected in the electronics and vehicle should be serviced-
never noticed if it came on as it sputtered and died, usually too busy looking for a safe spot to coast to.

- during normal operation, the skis will come on for 3 seconds after the ignition switch is turned on for a bulb check. if the bulb remains on then it indicates a malfunction in the electronics-
this is what happens after it dies. If i wait 5 minutes usually, it won't stay on and i can restart.

is it normal once the engine is running and you're driving for there to be a SKIS fault and kill the engine while your driving? if so, great ****ing system chrysler.

so is this problem is with the ignition key, the key cylinder in the steering column, or with the PCM?
i guess it beats having to drop the gas tank if it is.

2003 Jeep Grand Cherokee Laredo
4.0L, 4wd selec-trac, stock
ron7000 is offline  
post #3 of 9 Old 01-07-2010, 10:56 PM Thread Starter
Registered User
Join Date: Feb 2007
Location: CT
Posts: 37
you know what, this all happened after i had my batteryminder float charger on the jeep not too longer ago.
It has a pulse mode where once the battery is fully charged it sends a high frequency pulse into the battery to help desulfate it. One day while it was on there, i heard a light buzzing sound, coming from the radiator fan PWM relay. I figured that wasn't good, so i disconnected the both battery cables and charged the battery isolated from then. What's the possibility that had fubar'd the SKIS or PCM, how the hell do i figure that out?
But i also had the batteryminder on there over the past couple summers with the battery cables connected, although i never heard the PWM fan relay buzz like i did about a month ago.

2003 Jeep Grand Cherokee Laredo
4.0L, 4wd selec-trac, stock
ron7000 is offline  
post #4 of 9 Old 01-09-2010, 12:50 PM Thread Starter
Registered User
Join Date: Feb 2007
Location: CT
Posts: 37
put a new vehicle speed sensor (VSS) in at the suggestion of a mechanic, goes in the tail end of the transmission and was $17. That did not fix it.

I idle the jeep in the driveway for 10 minutes and it dies. Restarted the first time, moved it 10 feet then died and won't restart. The SKIS light stays illuminated on the dash. Wait 10+ minutes, turn the key to run and if the volt & gas gauge register, then it starts right up.
Have tried both sets of keys,
have tried the C/T and RESET button on overhead console prior to turning key on and it passes that SELF TEST.
getting flatbedded to the dealer,
per the service manual it says if the SKIS faults it sets code in the instrument panel cluster (not the PCM) that can only be retrieved with a DRB scan tool.

I have never had a code thrown that i can pull with a typical OBD-II scanner,
I will also get NO LINK with my scanner when the SKIS light is illuminated on the dash and the vehicle won't start.

I have also monitored fuel pressure on the injection rail, between 45-50 psi all the time. When the truck dies, it's still at 50 psi, so it is definitely not a fuel pump issue.

2003 Jeep Grand Cherokee Laredo
4.0L, 4wd selec-trac, stock
ron7000 is offline  
post #5 of 9 Old 01-09-2010, 12:53 PM
Registered User
2000 TJ Wrangler 
Join Date: Aug 2009
Location: Omaha
Posts: 28
since its gotten cold mine will not start unless I hit the unlock/disarm button like ten times >>>>>?????
john12v is offline  
post #6 of 9 Old 01-21-2010, 02:29 PM Thread Starter
Registered User
Join Date: Feb 2007
Location: CT
Posts: 37
well turns out I had replaced a crank sensor and vehicle speed sensor for nothing
after bringing it to the dealer eventually thinking it was the SKIM module and needing them to use their DRB scan tool to check,
the mechanic found the main wiring harness that runs from the PCM around the top back side of the engine (inline-6 4.0L) to the injector rail, had been sitting on the rear driver side valve cover stud and after 7 years/50k miles the vibration had allowed the stud to poke into the harness and short to ground three wires. That's what was causing the entire problem. At first the stalling out seemed random, then prior to bringing it to the dealer it would die within 3 minutes of starting it up.

During the diagnostic at the dealer, it died on them just like it had on me, they tried scanning the computer but found when it was dying that the computer was also being reset so no codes were being stored. And the way the mechanic explained that it was a short in the harness gave me the impression they've seen this before. It should be a TSB, because it was the way the jeep was built at the factory and is a definite problem, it will happen to everyone I think eventually if the wiring harness it tight around the valve cover and is touching on the valve cover studs.

After repairing the 3 wires, the harness was taped up and a piece of 1/4" rubber fuel hose was placed over the protruding driver's side rear valve cover stud so it doesn't wear through again.

I recommend anyone with the 4.0L inline-6 check the wiring harness running around the back of the engine and make sure it's not sitting on anything that can wear into it.

2003 Jeep Grand Cherokee Laredo
4.0L, 4wd selec-trac, stock
ron7000 is offline  
post #7 of 9 Old 01-21-2010, 06:17 PM
Registered User
Join Date: Mar 2009
Location: cranbrook
Posts: 1,443
key immodilizer doesnt cause stalling after the engine is running
baxy is offline  
post #8 of 9 Old 06-27-2013, 07:57 PM
Registered User
Join Date: Jun 2013
Location: Maywood
Posts: 1
Crank sensor was my problem

I had the same issue on my 2003 Grand Cherokee straight 6, 4.0L. Would be running fine, then just stall while driving. Pull over, wait a couple minutes and started back up like nothing happened. Sometimes it would happen 2-3 times on my 15 mile ride to work.

Finally got tired of getting stuck in the middle of the road in traffic so I took it to my mechanic. He said his diagnostic pointed to a bad crank sensor. He replaced it and it's been fine ever since. Cost me $300 but after watching a video on youtube on how to replace it, I wasn't even going to try it. It was worth the $300 to me. Although Im sure he padded that bill a little on a $60 part . Still, the peace of mind in knowing that I can drive now without having to worry about when & where it will shut down on me, is worth $300 to me.

Good luck to anyone else having this pain in the *** problem.
Jimrod is offline  
post #9 of 9 Old 06-27-2013, 08:36 PM
Registered User
1998 ZJ 
Join Date: Jan 2013
Location: Grove City
Posts: 434
way to resurrect an old post, but it needs moved to the WJ

2004 Lexus Es330, alive; 1999 Cherokee Sport
1998 Grand Cherokee, sold
1997 Grand Cherokee; Black and Gold, Limited 4.0....RIP 2005
to the good times and the bad, the family we have and lost, little brother 1988-2011
um7267 is offline  

Quick Reply

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
Jeep GC 4.0 dies randomly while driving, no codes no MIL, computer? ron7000 WJ Grand Cherokee Forum 54 02-28-2017 12:54 AM
Sentry Key Immobilizer problems PIAZ ZJ Grand Cherokee Forum 7 10-08-2014 08:27 PM
Intermittant Sentry Immobilizer Johnny B ZJ Grand Cherokee Forum 6 10-28-2009 07:40 PM
Immobilizer/Sentry key problems PIAZ ZJ Grand Cherokee Forum 4 04-19-2008 04:01 PM
engine dies, won't start, sentry key light stays on navest ZJ Grand Cherokee Forum 8 07-10-2006 09:47 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome