Is this a SKIM thing?

bluejeep

bluejeep

TJ Enthusiast
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Jul 29, 2019
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06 LJ rubicon, 135,000 miles, 6 speed.
Was driving in town (Galveston) and it died just after leaving a red light. Sputtered a bit, then went dead. Cranks fine but won't fire. I figured symptoms pointed to fuel pump so I replaced that. Trouble is it still cranks but no fuel getting to fuel rail (I disconnected it and cranked - still dry).

I also now see a P0633 code, SKIM key not known to computer.

I don't remember if the SKIM dash light was on when it first failed or not.

Does the SKIM key (grey) have a battery that can go dead (been 14 years)?
 
Yes.. there should be an amber circle with a key inside and a slash thru it in the upper left corner of the instrument cluster indicating the SKIM is not functioning properly.
The grey SKIM key has a chip inside and that is all; no battery to go bad.
The module or the key are not talking and the ECM is waiting for them to say its OK to start.
The chip or SKIM module can go bad,,,,
IF you have another grey key; try that one to see if its the key or the module that is not functioning.
When using the other key; IF the vehicle starts then the problem is the 1st key. IF the vehicle doesn't start then there is a good chance the problem is the module.
 
Last edited:
CharlesHS said:
Yes.. there should be an amber circle with a key inside and a slash thru it in the upper left corner of the instrument cluster indicating the SKIM is not functioning properly.
The grey SKIM key has a chip inside and that is all; no battery to go bad.
The module or the key are not talking and the ECM is waiting for them to say its OK to start.
The chip or SKIM module can go bad,,,,
IF you have another grey key; try that one to see if its the key or the module that is not functioning.
When using the other key; IF the vehicle starts then the problem is the 1st key. IF the vehicle doesn't start then there is a good chance the problem is the module.
Click to expand...
Thanks, I read somewhere to unplug the skim unit and vehicle battery, then plug back in, see if it resets. Thought I might try that tomorrow
 
bluejeep said:
Thanks, I read somewhere to unplug the skim unit and vehicle battery, then plug back in, see if it resets. Thought I might try that tomorrow
Click to expand...
I have only the one key, and the pcm is a replacement a few years ago, has worked fine until now
 
bluejeep said:
Thanks, I read somewhere to unplug the skim unit and vehicle battery, then plug back in, see if it resets. Thought I might try that tomorrow
Click to expand...

You certainly can try that...
What I posted will help you troubleshoot IF the reset does not work.
OUCH... only one key...

There is an APP that may help you...

CarKeysExpress.com/App
 
SKIS will not shut the engine off while driving. I would suspect that something else caused the stall and that the SKIS circuit is not activating for some reason. SKIS may be keeping your Jeep from starting now but something else is the source of the issue.

Notice any other issues, like cluster gauges not activating, trip meter resetting to zero or a No Bus message?
 
AjRagno said:
SKIS will not shut the engine off while driving. I would suspect that something else caused the stall and that the SKIS circuit is not activating for some reason. SKIS may be keeping your Jeep from starting now but something else is the source of the issue.

Notice any other issues, like cluster gauges not activating, trip meter resetting to zero or a No Bus message?
Click to expand...
None of the above. What is SKIS ?
 
CharlesHS said:
SKIS and SKIM are two different generations of Chrysler Immobilizers.
Click to expand...
True, but the same holds true for the SKIM system. Once the vehicle is started and stays running after recognizing the key, it won't stop the engine from running. You can check that with yours. Start it, reach behind the bezel and unplug the SKIM module, it will stay running.
 
bluejeep said:
Perhaps I was right about the fuel pump causing the original stall
Click to expand...
Possibly. Check the pump by cycling the key on with someone listening at the tank for the pump to turn on. It will turn on and run for a few seconds even with a SKIM system unless you have started it enough times to brick the PCM.

If you had working SKIM at some point and it is not working now, it will turn the key with the circle and slash on after the engine is started.
 
SKIS and SKIM are defined in the service manual and that's why I make a distinction.

SKIS refers to the system. SKIM refers to the module. The light in the cluster is the SKIS indicator.
 
mrblaine said:
Possibly. Check the pump by cycling the key on with someone listening at the tank for the pump to turn on. It will turn on and run for a few seconds even with a SKIM system unless you have started it enough times to brick the PCM.

If you had working SKIM at some point and it is not working now, it will turn the key with the circle and slash on after the engine is started.
Click to expand...
are you saying it's possible to ruin the pcm by attempting to start w/o a proper working skim module?
 
My TJ has SKIM. I cut a non SKIM (black) key that I use to unlock the steering wheel when I flat tow. I can tell you that the non SKIM key will start the vehicle ... it just dies after about 3 seconds.
 
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got my computer back from Mark at wranglerfix, installed, but still no start. I do believe the fix Mark put into the computer is valid, as the vehicle no longer throws a P0633 code.

So now I plan to go back to basics - the engine turns over fine but does not fire.

-is there spark
-is there fuel
-all all ground wires intact
-did i screw something up during the fuel pump replacement
-do i need to install the new leak detection part that came with the new bosch fuel pump (didn't feel it was necessary at the time)
 
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