Fsandefur

Let me tell everyone my sad (almost comical) tale.....

For the basics: 1999 Grand Cherokee Loredo 4x4 4.0L I6

I bought this jeep last year, and -surprise! - the previous owner had lost the remote, so I get only the one key. Given what the dealer and most locksmiths want for them, I purchased a blank transponder key and new remote from ebay. Everything so far is good.

My one related issue with the Jeep is that unlocking the door with the key will not disengage the alarm, but as so as the key is used in the ignition, everything is perfect again. My temporary 'fix' was simply to remove the horn relay so I don't have to listen to the horn every time I get in my jeep.

I determined from these forums that the likely culprit is the alarm wants a valid remote.

Fair enough. I had an appointment with the local Jeep dealer for the N47 recall, so I just took my blank key and new remote with me, and asked them to cut the key and program both. The key worked flawlessly, but the told me the fob "would not program".

I checked the batteries, found a bad connection, fixed it Went up to the locksmith. He tested the remote, determined it was functioning, and tried to program it. It would not program. On the theory that *somehow* the horn relay was the culprit, replaced it, tried again. Still won't program.

We got one of the locksmith's new remotes. Tried it. Same results.

I'm now thinking it's something internal to the jeep itself, but have no clue where to look.

Help??

Fsandefur

Since I'm getting several conflicting answers to this, just where is the actual RKE receiver? The most common answers I can find say it;s part of one of the front door modules, followed closely by it's a circuit board in the overhead light assembly

dave1123

The RKE receiver is mounted with screws to the inside of the passenger's front door panel. It is capable of retaining up to 4 different remote transmitter codes. When you are programming the remote, you are actually programming the receiver to recognize the remote transmitter's code, not the other way around. The SKIM module works the same way. Each key transponder has it's own code and the SKIM learns to recognize it.

All this stuff is covered in the Full Service Manual you can download from pacificcoastmanuals.com for 7.99 + tax. It's 93mb of pdf files and the best manual I've ever found. It's year specific for your jeep. This specific information is located in section 8p "Power Door Lock System."

Once you open the driver's door with the key, you should be able to cancel the alarm by unlocking all the doors with the driver's door lock switch. The alarm is supposed to activate automatically when the headlights are off, the key is not in the ignition, and all the doors are closed and locked. This includes the tailgate lift glass.

Fsandefur

Thanks Dave.

I just DL'd that manual, and at first glance it is going to be priceless.

Given the error the locksmith was getting, that RKE receiver seems to be the logical fault to me. It's where I'm going to start at least.

dave1123

It sounds to me like you're on the right track. This is substantiated by the fact that the dealer couldn't program your new remote. The worst thing is they didn't want to spend the time on such an "old" jeep! I've run into this at my local dealer. If it's more than 5 years old, they are reluctant to work on it. The parts manager is a great guy, but the service manager is an A$$! This is a rich bedroom community and he only likes to sell and work on new stuff. My friend took his lifted XJ there and they told him they don't work on "modified" stuff! They sent him across the city to another dealer.

When you figure out where your problem is, come back to us for more help. Your experience will help others. That's what this website is all about.

I can't take credit for that manual. I was turned on to it by Fred NOAZZ, another WJ guy. Also, check out wjjeeps.com

Fsandefur

Latest update: Thanks to the manual, I verified the actual receiver for the RKE is indeed internal to the front passenger door window/lock control module.

Simple enough. I got another unit from a 2000 donor vehicle, installed it...and I'm getting the same results.

I'm going to try and locate an actual electronics repair shop locally, and find out if it's possible to test the receiver itself.

I've had a few people tell me to check the BCM. It does interface with a lot of stuff, it is responsible for the vehicle anti-theft. My issue is this: if the BCM is indeed bad, why is it a single function has failed, and nothing else (as best I can tell) has been affected?

Back to more research for me I guess.

97grand4.0

"My one related issue with the Jeep is that unlocking the door with the key will not disengage the alarm,"
Of course you checked the worn out lock switch on the back of the driver's door key cylinder, ..right?

Fsandefur

oh yes. and the wiring. I've located a local electronics shop that claims they can test the RKE receiver and tell me if it's receiving and doing something with the signals from the key fob.

I'm down to, if the receiver is *not* functioning, repair that. If it *is* working, then the next suspect on the list is the BCM.

The shop is doing this as a favor, so it may be a couple weeks before I get an answer.

97grand4.0

When I was fighting my problem in my 97, I went as far as to pull a BCM from the boneyard, $10. Never got to try it out because I found the switch problem which is notorious on the 97's. Also helpful was a pinout of the bcm and a VOM.

Fsandefur

And the latest update: The electronics shop has finally gotten back to me, and it appears that both of the RKE receivers I now own are working properly So it seems my issues are down to the BCM, or bad wiring between the BCM and door module. I'll post it here when I finally resolve all of this.

dave1123

A dealer should be able to fix all your problems with an DRB III scan tool. The PCM needs to be told to recognize the RKE receiver. The WJ and newer jeeps work on a CAN-BUS system where all the modules talk to each other. While you're there, bring a new key and have them program it for you. AND a second fob.

buddy robinson

My zj its 4sale!!! If it dont sell i will lift it etc etc and its not 4soccer moms

dave1123

Caution!! Post has been hijacked!!

buddy robinson

Just bought it and the key itself does not work on doors and the key fob dont work any ideas how to fix?

dave1123

We've been discussing that on this thread and there's plenty others if you look.

A 5.9 ZJ shouldn't be on the market long.