sentry key engine immobilizer light

This light came on in the dash today (at least I think that's it from the quick reference booklet I have). I have a new-to-me 2001 Grand Cherokee (owners manual on back order). Anyone know what this means?

If it stays lit while running, it means a fault has been detected in the electronics. The manual won't tell you what's going on.
You can cycle the key on and off 3 times, then leave it on and read the fault code the odometer displays.
That's a start.

If it stays lit while running, it means a fault has been detected in the electronics. The manual won't tell you what's going on.
You can cycle the key on and off 3 times, then leave it on and read the fault code the odometer displays.
That's a start.

Thanks a lot. I did that and got the fault code P1685. Stopped at the dealership and they said they'd have to run a diagnostics test. Any idea what this code means?

P1685 - Engine controller has received an invalid key from SKIM.

P1685 - Engine controller has received an invalid key from SKIM.

Ok- I think I know how I got it too. Is there any way to re-set this without going to dealership?

Well, here's my guess. Being a new car, you accidentally tried to start the Jeep with your old key. This caused the system to trigger an invalid key code.
The check engine light will extinguish its self after a pre set number of good starts---its possible the immobiliser light will do the same.
So if you want to stay away from the dealership, just drive it a while.
As long as that's the scenario, driving it should not hurt a thing.

Well, here's my guess. Being a new car, you accidentally tried to start the Jeep with your old key. This caused the system to trigger an invalid key code.
The check engine light will extinguish its self after a pre set number of good starts---its possible the immobiliser light will do the same.
So if you want to stay away from the dealership, just drive it a while.
As long as that's the scenario, driving it should not hurt a thing.

Thanks for your reply. Actually I had a key made at the hardware store (not realizing it needed to be a special one) and tried to use that. It started and cut out, of course. This was three weeks ago. Seems odd it would take that long for the error light to show up, but that is the code I'm getting. I'll drive for a while and see if it goes away. I think that only the check engine light is on- the booklet I have describing the intrument panel lights isn't too accurate.
Many thanks for your time.
Sue

Here are some illustrations that should help you make sense of what light you are looking at.

The check engine light should look like this-
http://www.wjjeeps.com/check_engine3s.jpg

Here is an illustration and explanation of the dash lights-
http://www.wjjeeps.com/02gauge2.jpg

P1685 - Engine controller has received an invalid key from SKIM.

Ok- this time I re-did the key turning until the lights said I was finished and I also got the code P0456, which I saw on this forum means EVAP Leak Monitor Small Leak detected. Do you know what this means? Should I get it in to be fixed quickly?
Thanks for helping.
Sue

Ok- this time I re-did the key turning until the lights said I was finished and I also got the code P0456, which I saw on this forum means EVAP Leak Monitor Small Leak detected. Do you know what this means? Should I get it in to be fixed quickly?
Thanks for helping.
Sue


I am not finding a P0456 fault code..

the code you described is P0442 or P0455

Ok- this time I re-did the key turning until the lights said I was finished and I also got the code P0456, which I saw on this forum means EVAP Leak Monitor Small Leak detected. Do you know what this means? Should I get it in to be fixed quickly?
Thanks for helping.
Sue
From www.wjjeeps.com/faultcodes.htm
===
P0456
Evaporative Emission Control System Leak Detected (very small leak)
A 0.020 leak has been detected in the evaporative system.
Also, possible faulty or loose gas cap.
===
Basically, it means that raw gas fumes are escaping into the atmosphere.
Not a real urgent problem, but it won't pass smog like that.
According to Chrysler there could be other issues, but start with the simple stuff like the gas cap.

From www.wjjeeps.com/faultcodes.htm
===
P0456
Evaporative Emission Control System Leak Detected (very small leak)
A 0.020 leak has been detected in the evaporative system.
Also, possible faulty or loose gas cap.
===
Basically, it means that raw gas fumes are escaping into the atmosphere.
Not a real urgent problem, but it won't pass smog like that.
According to Chrysler there could be other issues, but start with the simple stuff like the gas cap.

Once again, I thank you very much.

From www.wjjeeps.com/faultcodes.htm
===
P0456
Evaporative Emission Control System Leak Detected (very small leak)
A 0.020 leak has been detected in the evaporative system.
Also, possible faulty or loose gas cap.
===
Basically, it means that raw gas fumes are escaping into the atmosphere.
Not a real urgent problem, but it won't pass smog like that.
According to Chrysler there could be other issues, but start with the simple stuff like the gas cap.

Ok- you were so right (again). Took it to the dealer and it had a "faulty" gas cap. Now all is re-set and I hope I have no further problems.
Thanks so much for helping me.
Sue