The Famous Jeep Grand Cherokee Electrical Problem

All seem to be control center issue... Buy Haynes repair manual for jeep of your year... You have two fuse boxes, one in engine area and one inside car...check/replace all fuses first.

grand cherokee stalls or dies out.


1) CHECK YOUR CONNECTIONS AT THE ECU (ENGINE CONTROL UNIT) MAYBE CALLED THE PCU (POWERTRAIN CONTROL UNIT) ON THE PASSENGER SIDE FIREWALL. ON 1998 AND EARLIER THE 3 PLUGS SOMETIMES GET A BAD CONNECTION. IT IS USUALLY THE ONE CLOSEST TO THE FENDER. UNPLUG, SPRAY WITH CLEANER AND REPLUG. YOU MAY EVEN HAVE TO WRAP A ZIP TIE AROUND THE UNIT TO KEEP THE PLUG IN TIGHT.


2) THIS MAY ALSO BE THE PROBLEM, IT IS GOING TO SOUND SCREWY BUT THERE ARE TORX SCREWS ON THE 1998 AND EARLIER ECU. BACK THEM OUT ABOUT A THIRD OF A TURN, THE SCREWS ARE TOO LONG AND ARE CAUSING SOME KIND OF SHORT IN THE CONNECTION.


3) FOR 1999 AND LATER


I had same problem.... 87,000 2000 grand cherokee 4.7l
when i let off the gas it might stall. happens 1 to 4 times a day.
so far i have
replaced the crank shaft sensor - it stopped stalling for 3 days $130
cleaned the throttle boddy free
replaced the throttle position sensor $72
replaced the idle air control sensor $132
replaced the map manafold airflow sensor $125
no luck it is still stalling. not sure if i remember the prices
right on these parts....
by the way i have done all the work myself. it was about 30 minutes for most parts.
i just ordered a rebuilt ecu or pcu engine control unit. they program in the vin, mileage and part nbr so you gc will recognize it. $185
we will see when that comes.....

IT CAME AND THAT SEEMS TO HAVE FIXED THE PROBLEM..... BEEN A WEEK.... SO FAR SO GOOD

alan

I am a Jeep owner in England my car is a 2000 G.C. 4.7 v8 I bought this car 5 years ago [one owner full history 18000 miles fro new].
It was fine until 2 years ago when it suddenly cut out while my wife was driving.She called the AA who could not fix it so towed it to the nearest Chrysler/Jeep dealer, they had the car for 2 weeks trying to fix it.They eventually said that a wire had rubbed through on the steering column which caused a short which blew the Body Contol Module.They replaced the module put the car back together and gave me a bill for

You may want to check these few things below....
mine was not that bad. but it shut off like the key was turned off.... no studeer or misfire.... and it always started right back
got mine fixed with the very last option #3, I HAD TO REPLACETHE BRAIN (ECU) Got mine off ebay for $185. but i see you have already done that. maybe option 1 or 2 can help..... good luck old chap...


grand cherokee stalls or dies out.


1) CHECK YOUR CONNECTIONS AT THE ECU (ENGINE CONTROL UNIT) MAYBE CALLED THE PCU (POWERTRAIN CONTROL UNIT) ON THE PASSENGER SIDE FIREWALL. ON 1998 AND EARLIER THE 3 PLUGS SOMETIMES GET A BAD CONNECTION. IT IS USUALLY THE ONE CLOSEST TO THE FENDER. UNPLUG, SPRAY WITH CLEANER AND REPLUG. YOU MAY EVEN HAVE TO WRAP A ZIP TIE AROUND THE UNIT TO KEEP THE PLUG IN TIGHT.



2) THIS MAY ALSO BE THE PROBLEM, IT IS GOING TO SOUND SCREWY BUT THERE ARE TORX SCREWS ON THE 1998 AND EARLIER ECU. BACK THEM OUT ABOUT A THIRD OF A TURN, THE SCREWS ARE TOO LONG AND ARE CAUSING SOME KIND OF SHORT IN THE CONNECTION OR MAYBE THE GROUND.



3) FOR 1999 AND LATER

I had same problem.... 87,000 2000 grand cherokee 4.7l
when i let off the gas it might stall. happens 1 to 4 times a day.
so far i have
replaced the crank shaft sensor - it stopped stalling for 3 days $130
cleaned the throttle boddy free
replaced the throttle position sensor $72
replaced the idle air control sensor $132
replaced the map manafold airflow sensor $125
no luck it is still stalling. not sure if i remember the prices
right on these parts....
by the way i have done all the work myself. it was about 30 minutes for most parts.
<b>i just ordered a rebuilt ecu or pcu engine control unit. they program in the vin, mileage and part nbr so you gc will recognize it. $185
we will see when that comes.....

IT CAME AND THAT SEEMS TO HAVE FIXED THE PROBLEM..... BEEN A 3 WEEKS.... SO FAR SO GOOD</b>
alan

I'm no pro, but sounds like everything that you described keeps coming back to Security system issues. If the car thinks that the security system is breeched... it will shut down

Rubbed wires in steering column... Why? Was the car broken into?
1) Faulty sensor key? or faulty key switch in column?
2) Key less remote maybe faulty?
3) Door (security) actuator switches in door jamb, maybe faulty? ... My top door hinge came loose and door was not making good contact with door jamb switch, causing security system to open and close... shutting off car.
4) Check/test/replace Security fuses in Body and Engine control boxes for voltage and proper ground, using jeep manual.

Report back, when you find the answer...

I have a 1998 Cherokee 4.0L and I have been having an electrical discharge problem for a couple of years.
I replaced the battery last year and it has been fine since but now the cold weather is here, the battery is running out of juice again

I have disabled the alarm (removed the fuse), had the electrical system tested by an auto electrics specialist who said the alternator is fine and he couldn't find any major earth leaks and I've removed and replaced all the fuses.

I had the same problem with the rad fans spinning after the Jeep was switched off (as a couple of earlier posters described) and it is a faulty relay - look for the one which controls the rad fans.
If you pull it out and start the Jeep briefly it will run without the fans.
A replacement is pretty inexpensive and is a push-fit so anyone can do it.

I am going to check the wiring loom for chafing and also check my PCM connections for damage and corrosion - does anything else spring to mind for me to look at...?

Many thanks

When I said 'check my PCM', I meant my ECU...!

First off, I'd like to thank everyone for all of your posts!

This forum has been a helpful resource for me so I thought I would share my 99 Jeep Grand Cherokee Limited experience. A check lift gate warning, interior lights and door locking ghost would appear intermittently when driving and when parked the alarm would go haywire. I disconnected the fuse for the alarm and put up with the interior malfunction for a couple years until my jeep started having trouble starting. I took it in to the dealer and after $1,000 worth of trouble shooting they solved the electrical issues by replacing the BCM (Body Control Module).

Now the vehicle is left with issues when starting that are worse than they were before I took it in (will often stall when starting up an needs constant gas before staying idle). The mechanic at the dealer says the issues are not linked, and so rather than take this back to the dealer I will trouble the idle issue myself, again thanks to this post. I'm hoping that cleaning the Idle Air Control Motor (IAC) will do the trick, but with my luck I will have to replace the PCU/ECU. I'm at the point where repair is almost too close to value of the vehicle to justify.


I understand the difficulty of a mechanic in trouble shooting these issues, and their time is money. Ultimately the fault lies with Jeep, which is a shame because these things run like a beast. I will not purchase one again after this unless it's just a third offroading vechicle.

Thank you,

2000 Jeep Grand Cherokee Laredo that looks and runs like a new vehicle; 111K miles. 2 months ago, after leaving the vehicle outside for two weeks (while out of town), upon my return, I discovered that the gauges weren't working (or working intermittently), with all the dashboard lights lit up. Other symptoms: the overhead console and windows not working.

Finally got sick of dealing with the issue, and dropped off with a mechanic. He's had it for FIVE DAYS and hasn't had any success in solving the problem. Both he and I traced the problem (via diagnostics) to the instrument cluster bus (within the dash). However, he hasn't resolved the problem to the gauges not working (whether it's a short, or another problem causing the malfunction).

Has anyone had any success in solving the problem of the gauges not working? How about any suggestions?

I have the same exact problems as MPRinOhio. It seems like the only time I have these issues is when it is cold outside. It started with my key fob not working to unlock or lock the car back in July. I would have to use the key to get into the car and all of a sudden the key would not disable the alarm so now I have to lock the door with the lever instead of the electrical switch so the alarm doesn't activate. I then noticed a clicking sound coming from my passenger side window control and the lights would blink on and off. I would be driving and all of a sudden all of the gauges would stop working and all of the idiot lights would come on. My electric windows and door locks would not work or the console that has the temperature and mileage stats. I also have radio controls on my steering wheel that are located in the back of the steering wheel. They will stop working but my cruise control located on the front of the steering wheel does work (strange). Sometimes while driving everything would go back to normal except the light that has the key with the slash through it, it would stay lit on the dashboard. If this happened, all of a sudden my rear CD player would start working. This happened to me again this morning and when I turned off the car, my power outside mirror motor started running causing the mirror to go up and would not stop, even with the car off. I had to go under the hood and unplug the fuse so I would not wear my battery down. It seems like more things keep adding to the list of electrical problems. Luckily I have not had my car stall out as I have read in other posts, I would like to fix the problem before that starts. Any suggestions?

The electrical issues with the gauges on my 2000 JGC seem to act up worse when the weather is cold. As I drive the vehicle (and the vehicle warms up), the gauges will intermittently turn on and off, as will the dashboard lights.

With as many JGC owners that have experienced this issue, it's odd that at least ONE person hasn't come up with a solid resolution.

CRWEST52...appreciate the feedback. The Jeep is back to the electrical mechanic tomorrow, and I'll have him check out the ground connections.

My 99 GC Laredo has the same identical issues. IE; clicking/ blinking window switches, haywire gauge cluster and compass (above the rear view mirror), and while all of this is going on I have no windows or door locks. Once in a great while it doesn't want to start and I have to keep the RPMs up for a bit before it will stay running.
My husband works at a JEEP/ Foreign car dealership, and always figures out the origin of the issue.. Not this time. His boss drives a 2001 GC, had the same issues as mine, and had completely gone through the thing to no avail. Each time it would eventually act up again. He got two used window switches from the junk yard, and his problem is solved. Not so much for us. We have replaced fuses, door switches, swapped the gauge cluster, and the PCM. One way I have dealt with the issue- When I get home for the night- I take off the battery terminal. When I put it back on in the morning it its fine for 12 hours or so. The trick being it has to be off for more than 6 hours or everything goes haywire shortly there after.
Tonight my husband unplugged the passenger side door switch to see what happens, thinking maybe we got another set of switches that have the same issue as mine?? We'll try it I guess.
A question for you guys too.. My Sentry Key Light in my gauge cluster is ALWAYS on. It was in the boss's rig too. Even if the Jeep is running properly it stays on, it did on the old gauge cluster too. My Jeep does not have the Sntry key system set up.. Anyone else's stay on? Best of luck to everyone, I'll keep checking in on here, I am so over this issue, I will try just about anything to fix it.

The gauges on 2000 JCG started malfunctioning after I left it sit for 16 days while I was out of town. Briefly disconnecting the negative terminal, and then reconnecting seemed to temporarily re-set the electrical system; i.e. the gauges came back to life, and the dashboard lights would go off. However, after a brief period of normalcy, the problems would reappear.

I took my vehicle to a mechanic that has experience with electrical issues. After 7 FULL DAYS with the car, he found NOTHING. I picked the car up last weekend, and thought I'd try what I thought would ultimately be a waste of time.

It's been mentioned in several online posts, to disconnect the battery for 10 minutes or more, then reconnect. I did so...for approx 1 hour. Had the car now for 4 days, and electrical problems seem GONE! Gauges are normal; no dashboard lights; overhead console works; door locks work. I also checked the diagnostic codes on my vehicle, and the ones that existed previously, were also gone.

Even though my vehicle is 9.5 years old, apparently there are approx 8 computer systems (or processors) in the vehicle that need to be integrated (i.e need to talk to one another). I'm thinking that it's like a router or a home PC...a re-boot solves many issues. In the case of the car, a disconnect of the power supply for 10 + minutes may reset all of the processors.

Seems to have worked in this case. I wish that I would have attempted the resolution before taking it to the mechanic. $$$ down the toilet. Chalk it up to American ingenuity at it's finest.

I've posted before, but here's an update: after 6 months and almost $3000 in repairs, i think, I THINK, that the problems might be resolved: problems like everyone else, cluster panel bouncing around, windows and door locks not working, engine dying, AND ALWAYS, the key entry light ALWAYS ON. It ending with replacement of the PCM. My dealer was stuck and kept on dianosing and testing the system. A LOT of contacts with Chrysler mechanics by the dealer. My dealer and mechanics were SUPER! I've still got my fingers crossed. After reading all the postings here for help (which I ran off and gave to my dealer) here's what I think: There is not a cut and dried solution to a straight problem. AND I don't think Chrysler really gives a flip or they even know. We've got a product that should be recalled every year. It may be in the hugh electric harness of wiring. Probably, this should be replaced at Chrysler's expense (it will never happen). So, this will be my last Jeep. I think Jeep was good until Ioaccoca left and Chrysler took over production. Sorry for the negativity, but folks, we spend a lot of money to have to spend this much for a mysterious problem and resolution is a ???? at that. Good luck to the rest of you. Thanks for posting and comments. They sure helped us.

I feel everyone's frustration in here with the electrical problems. It's just difficult to fathom how one can invest thousands in a vehicle that (1) probably isn't worth $4000, and (2) the great, expensive resolution from the dealer quite possibly won't fix the issue. Replacing the PCM is always the dealers way out. Hopefully that fixed your problem, but if not, then what? Back to the dealer for more out of pocket $$$?

This was posted on http://www.allpar.com/fix/gauges.html; it relates to the the same problems (dead gauges, etc) on a Plymouth minivan, but it sounds like his issue ultimately was with the BCM.

My wife's 92 Plymouth Voyager minivan instrument cluster went on the blink. Every gauge in the instrument cluster was dead with the "check gauges" light on. This means no speedometer, odometer, fuel gauge, etc., almost like driving with blinders on.
The factory service manual states the mechanical instrument cluster is electronic with analog display gauges. All messages to the instrument cluster gauges are sent over the "CCD" bus from the body computer. The CCD bus is a two wire differential communication bus which allows the micro-processor in the body computer to communicate with the instrument cluster microprocessor.
I called the local Plymouth/Chrysler dealer and they said they would fix it (for a small fee $$). After questioning them on what they do to fix it the service rep broke down and said it goes to an outside specialty repair service company that just fixes onboard auto electronics. He was nice enough to give me their name and phone number, and said I could go direct to them for the repair of my instrument cluster.
Ray Parker wrote: ?Hey, I just fixed my 89 year old mother's 1992 Dodge Caravan by following your instructions. I replaced only the Q110 transistor as all her gauges were dead, and put the body computer back in and voila, it worked again, thus saving her a bucket of money. Thanks.?
I called this specialty repair company and told them my problem with the nonfunctional instrument cluster. They said they would be glad to fix it for $229 plus $58 removal/installation. I asked to speak to a tech to help me diagnose the problem over the phone to be sure this was the problem. A tech came on the phone and after telling him about my instrument cluster failure he said the problem is not in the cluster electronics but with the body computer! They have repaired over 1,000 of these body computers and it has fixed the instrument cluster problem only by replacing it with a later model body computer. The tech asked me to check the part number on the body computer to see if it was a 4686058 (it was). This part number was known to fail and the fix is to replace it with a new model 4741423 body computer.
Since I figure I was out $300 I decided to pulled the body computer module and check the PC board out myself. The body computer is under the steering column cover just to the right of the steering column in a sheet metal box with two large connectors. Once the cover is off it removes very easily with just two screws, but you should pull two connectors cabled to the body computer first. The body computer sheet metal cover has one screw (star type) attaching it. I removed this metal cover and popped out the pc board. It is a typical high volume low cost circuit board with a Motorola microprocessor and lots of discrete parts (capacitors, resistors, transistors). I took out my trusty digital volt/ohm meter and after a few minutes found two bad transistors, Q105 and Q110. The transistors were both found to have open base-emitter junctions. Without a schematic, I could trace one transistor to the chime transducer and the other to what appeared to be a bias for the "CCD" bus. Both were marked with factory numbers but I could deduce that the were "NPN" type transistors in a plastic TO-92 package. I called my brother, an EE who has an electronic lab in his home, and ask him to recommend a substitute part. He said he has a drawer full of 2N3904 (which you could pick up at a local Radio Shack for less than a buck) and to come over and get a couple. After carefully unsoldering the defective parts and soldering in the new transitors it would be a matter of minutes to check it out. I reinstalled the body computer and upon inserting the key into the ignition with the driver side door open I heard the familiar "key-in-ignition" chime again!! Good so far!
Now I started the engine and all the instrument cluster gauges came alive again!! Success!!! My brother figured the original transistors were from a bad batch and were doomed to a short life (about 4 years I guess).
I don't recommend this repair approach for everyone, but with some electronic knowledge you should be able to do this body computer repair yourself saving hundreds of dollars.

where is the Q 110 transistor? i have looked everywhere and can not find it. i see the D 110 but no Q 110.my door chime works its just my gauges are out. what is odd tho is they go on and off. the gauges will work for a while then go out. if you could help i would greatly appreciate it! thanks

if you do need one you can et if off ebay for about$180...... programmed and shipped. replaced mine in about 30-40 minutes. it was plug and play and fixed my stalling when i came to stops or slowed down..
good luck
alan

Thanks to all you guys for your help and info. Unfortuneatly I have tried most things suggested and the problems still persist.I have checked for loose connections,screws that are too long or anything that appears loose.The sentry key light [thats the one with a picture of a key with a line through it] has started coming on while driving.sometimes the car starts and runs fine then other times the engine cranks over but wont fire at all.When this occurs the sentry key light stays on and the fuel guage goes off the end of the scale past empty.The problem is much worse during wet weather which makes me think it must be a bad connection that is getting damp in it.The car sits outside at night and if it is damp in the morning wont start until the sun has been on it for a while!
I have borrowed a factory manual from my local garage which has helped to identify the various modules but is impossible to troubleshoot them without the diagnostic equipment to plug in.
It would appear to me that Chrysler have built an over complicated electrical system into their cars which coupled with a lack of build quality is causing all these problems.What happened to the good old days when JEEP stood for Just Enough Essential Parts?
I will carry on trying to get to the bottom of this and post any relevant info.
Regards Julian.

Julian, there's a trick that is advertised as working for Cherokee's (and works for my 2000 JGC, so it may work for yours), in determining the diagnostic code for your problem. Put the key in the ignition, and turn it backward, and then back to neutral (toward ACC) three times. It should flash a code that begins with the letter "P" where the mileage is displayed on the dashboard. When the process has completed, you will see the word "Done" displayed. Get the code, and research it on the internet. That may or may not indicate the problem, but it will give a place to start.

I agree. The JGC is full of design flaws that may have been good ideas at the time, but that are coming back to haunt many of us. Someone has to have had some success in resolving the electrical problems. JUST DON'T TAKE THE CAR TO A DEALER FOR ASSISTANCE!! Dealers are famous for replacing parts that may not solve the issue, but that puts $$$ in their pockets.

Please post anything that you find. Thanks.

Just went through a cold spell and my lights are crazy, either all interior lights on, everything all the time -or everything off, no dashboard, no lights when door opens, nothing. I discovered I can control this through the dimmer on left arm dimmer switch.

Also there are no power windows or locks.

Car generally runs fine, 42K miles, owned since 12K bought from dealer. I generally stay away from dealer, but my regular maintenance/repair guys are not interested.

Suggestions please-Not sure about this ECM, BCM- can they be purchased other than dealer and can general mechanic reset these??

I have a 2001 Grand Cherokee 4.7L with 83k miles. Never had an electrical issue. I brought it to local mechanic because the check engine light was on. The mechanic hooked up his diagnostic machine to the cars computer and said it needed an o2 sensor. When he disconnected the diagnostic machine I lost the power windows, automatic headlights, interior lights, and overhead display that shows temperature gas mileage and distance to empty. I informed the mechanic and he said when he replaces the o2 sensor he would look into it. He checked the fuses, found no problems and said it was just a coincidence that it happened when he plugged in the diagnostic device and he couldn't help me. Luckily I found this forum and read a post that said to disconnect the battery for 10 minutes and that the computer would reset itself. I disconnected the battery and crossed my fingers and it worked. Thanks to the post everything is working properly again.

Finally found a competent tech at a Strauss Auto- he traced system and fuses all fine. It was broken wire in the driver's door boot like lot's of others have said.

1.5 hrs later and $170 lighter, my windows and locks work and I'm happy.

I don't think the dealer would have let me off so cheap. Good luck to everyone.

I have a 2000 jeep gc/limited 2 wd 4.7 v-8 which exhibits all the intermitent computer problems that are posted in this forum. The dealer has not been able to provide a fix after replacing 2 BCM, 2 PCM, AC evaporator, fan, relay, crankshaft sensor, battery cable clamps and now recommending replacement of instrument panel and SKIM module. I have tighten every visible ground. I would like try your fix. Please be more specific as to how to get to the security box which you stated is located behind the glove box.

This was posted by fdny136 under "Jeep Electrical". This is in the same area as the glove box, you might try it as well.


(by fdny136 - 3/23/10 7:23 PM In reply to: RE: by nomorejeeps)
I have recently repaired,after numerous hours diagnoising the bus line a 2000 grand cherokee with the symtoms described.this vehicle came to me after having a new battery,cam and crank sensor,ecm and bcm.the problem with this vehicle was on under the passenger kick panel.here you will find 2 wire harness junctions the upper harness was water damaged and corroded the solution was to use electrical contact spray and clean well,dry and treat with dielectric grease.this solved all the electrical gremlins described on this particular jeep

This is a similar problem to mine.

I have narrowed it down to the radiator cooling fans which seem to switch on and off every 12-15 seconds even when the ambient temperature is well below 0

Not that I am aware of, but will check. Have been reading other internet posts and a replacement PCU and frayed wire in or near the wire harness were mentioned as possibilities.