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Jeep Grand Cherokee Transmission Problems



  • Any suggestions, my 2007 Jeep Cherokee has the same exact problem? thanks
  • My 95 jeep is doing the same thing. A few weeks ago I decided to fix my engine leak at the head gasket, so I took the Intake and head off and replaced It the leaks still there and when I test drove it the tranny did the same thing. I think a sensor I touch during the head job caused it but I don't know. If you look at some of my post i've got some good resposes maybe it will help you out.

    What engine work did you do because there's alot of things that factor into the tranny. let me know what you find, if find somthing i'll let you know good luck!
  • I wiggled the harness at the intake all around where the TPS and MAP sensors are. Now there's a code for the TPS voltage. I'm going to rip back the tape and trace some wires maybe i'll be lucky. My brother the machanic told me to try driving it with out the kickdown cable and it shifts like it's been but alittle worse so we know the cable is working. I'm going to cleat the codes after I look at the troubleshooter in the scanner, which my brother will do may i'll find something.

    I read an article you posted the 42RE about a default mode on the TCM, which is 3rd but manual shifting is possible, and that modes from a fault code, what does this mean, there a way to reset this TCM? Thank you!
  • i dont know much, i think it was a transmission control module that they replaced. i actually had to leave my jeep there and they went out several times a day and tried to start it until the "transmission over temp" sign came on and it didnt start. then they hooked it up to their machines and figured it out from there. they cant fix the problem until it actually doesn't start. at least in my case, my jeep would start for a while, then just out of the blue, it wouldn't start. good luck, hope this helps.
  • loosenutloosenut Posts: 165
    seems dalmer/chrystler's decesion to farm out their soldering to third world countries did exactly what they needed it to do..last ten years,then-good luck !
    --after re-soldering mt headlight switch,my headlights don't blink on and off like the alarm has works fine now..
    --my best advice is to get a tube of DIELECTRIC GREASE-available from electrical supply places,then anytime you unplug ANYTHING-give the connection a good coat of that non-conductive least it will slow the contact corosion problem these trucks seem to be plauged with--even when you change a bulb !

    people--PLEASW CHECK YOUR TAILIGHTS AND BRAKE LIGHTS!..this annoys the hell outta me when people don't seem to care if their lights work ! the simplest way is to see your reflection in a store window !..might keep someone from hitting you!
    to keep the break pedal down to check brake lights-i use a hammer weged between the pedal and the front of the seat !but don't leave them on too long,as they get hot !..makes changing them harder.. :sick:
  • amabamab Posts: 2
    Hi , I need help !! my 2001 jeep has 150K on it , and when i take off the car is so heavy like putting a lot of effort ( i assume the transmission starts from the 2nd)
    and it will not shift to 3rd or 4th unless i start driving with the shift is on 2 and when i aproch a highway i shift it to D and OD then it runs smoothly , it used to do that once in a while but now it does it everyday , took it to the mechanic he said rebuilt or change the transmission which i will not do and prefer to sell the car instead if couldnt fix the problem , so please Help !!
  • nnealnneal Posts: 72
    If you wiggled the harness and got a trouble code when there was none, it seems like there's a bad connection (or wire). Be careful as I have, of tripping a code by unplugging a sensor or something else.

    The 42RE article about the default mode means if the TCM has a trouble code set, then it places the transmission in default mode as you described. On my 98 Cherokee, when I erase trouble codes with the scanner, it erases trouble codes in everything (engine computer and TCM). On my Jeep, I can only read the engine computer trouble codes, and not the TCM. I'm told I need a DRBII scanner to read those which the dealer has and is very expensive. I was surprised by some Jeeps with the 42RE, having the capability to read trouble codes of the TCM separate of the engine computer. I don't know if yours has an overdrive switch, but this is what the article described:

    "This system has self-diagnostics. Fault codes can be read with a scan tool or by cycling the ignition key three times, then counting the flashes of the LED in the OD off switch."

    Good luck and keep us posted on what you find.
  • Yes I think a wire is bad I haven't checked yet.

    My Jeep is a 95, with the OD off switch, which is before the OBD-II scanner connector, mines the OBD-I connector, there is one in the engine bay at the computer which we looked at and some codes were on that we caused, and then I found a plug inside for my TMC. The scanner we have reads the TMC and the computer, from that we got alot of readings, but I had no codes when I had the scanner in. Now with the flashes you said about I checked because I didn't have the scanner and I have TPS codes in both computers, this is after I wiggled the wiring harness a few days ago.

    How do you know if it's in default mode, from the articles my symtoms would say but i'm not sure. I guess the scanner will reset this.
  • nnealnneal Posts: 72
    The way I translate the article (link title), default mode is when you place the transmission in "drive", it automatically goes to third gear. You can make it go to reverse or second gear by manually putting it in that gear yourself. Seems like you have a choice of three gears while in default mode. To me it doesn't sound like you're in default mode because you have all your gears, they're just not shifting right.
  • nnealnneal Posts: 72
    My 98 Cherokee with an AW4 transmission had the same symptoms. Not sure what your transmission is. I brought mine to a transmission repair shop for a free first time estimate, and all he could tell me he was the fluid was a little dirty and he didn't know what was wrong. According to him, my only option was a total rebuild. Then I thought, what the heck, I'll bring it to the Jeep dealer, with all their tools they will know what's making it act up. I got the same answer from them, only this time I was a $100 poorer.

    I knew the "guts" of the transmission was alright, because like yours, once I got it to drive it ran normally. Only when I came to a stop, it would not shift down to first unless I manually put it there (in order to take off again). So with nothing to loose, I bought a solenoid kit consisting of three solenoids off the web and installed them. To my surprise that's what my problem was.

    If this is what you decide to do, look around at some of the transmission parts sites on the web for solenoids. The Jeep dealer wants an outrageous price for theirs. I got all three solenoids (the kit) off the web for LESS than the price of one from the Jeep dealer.
  • Sounds good to me. I had the scanner hooked up tonight with my brother watching it and everything is working and there's no codes, we cleared them so now I'm going to drive it tomarrow and see what happens. It tells me the readings of all the sensors to do with the tranny, so I want to see if they are correct. Also the scanner says that everything is good and ok to drive.

    Do you think the TCM could have gone bad. I was reading about them and TCM tells the tranny when the best time to up shift and downshift, but there is only one shift solinod in that tranny which is for the OD and the rest I think is controled by shift valves. and the solinod is working because I have all gears.

    I need to look at the engine again I ran out of time. I want to check wires to the TPS.
    Thank You!
  • nnealnneal Posts: 72
    From what you've discovered so far, I don't think the TCM is bad. I have a spare one which I used to switch with the factory one to rule out the TCM, and that has never gone bad on me. I've read some people have had the dealer reprogram (or Flash) them, but it's not cheap. Yes, from what I read your TCM controls the solenoid for 3-4 upshifts and back down. Shift valves control the 1-2 and 2-3 upshifts (and back down I assume - they don't say). But what actually controls the shift valves themselves is the TCM, because it controls what the governor pressure solenoid does - and that is how much pressure the shift valves have to work with. So actually, there are two solenoids, one is a shift solenoid (3-4) and the other is a governor pressure solenoid (valve body), from which controls your shifting. The clinker in all this is that your TCM relies heavily on inputs from all your sensors, so they make a good weak point.

    One thing I thought of and read somewhere, is make sure the ground strap from the engine (or tranny) to the frame is good, otherwise it will mess up all the electrical parts and make them act strangely. Especially after working with the head, there might have been one connected to it.

    You're lucky you've got the tools and a brother who knows what he's doing. Best thing is, don't get discouraged because in the end I'm sure you're going to find it's only a wire or small component that's screwing things up. I've been there many times.
  • tuggajbtuggajb Posts: 646
    there is a ground strap from the back end of the head that you could have forgot to hook up
  • There's not one of them on mine but I know what you mean. When my brother work on his cherokee a few weeks ago (headgasket) we had to unhook that strap, but the only thing that is in the back of mine is a plug, I think with one wire and I checked I out and played with it and it didn't change anything. Do you know what that wire is for. It screws in to the head then a plug hooks on?
  • There was no ground strap on the back of the head like my brothers, a one wir plug which I had to unhook. This screws down into the head then the plug hooks on from the harness. Could this be my ground to the head.
  • nnealnneal Posts: 72
    Could very well be. Either way, the transmission has to be grounded to the frame in some way for it to work right. A corroded ground would cause the same problems. My Jeep has a flat braided strap (wire) from the head to the firewall. I don't know what 95 models used.
  • nnealnneal Posts: 72
    I would like to add a request to all the people posting their vehicle problems in this forum. If you have found what was causing the problem in the message you posted, please let the rest of us know what your solution was so we can all benefit by it. I've learned and discovered many solutions in forums like this not found anywhere else. Many of them are not to be found anywhere, not even from the manufacturer. Forget garages and transmission specialists, as they are not going to throw away easy money. Feedback benefits everybody! Thank you.
  • You think oil will make a ground short out because there is oil on some of the plugs and I've been spraying them with WD-40. I'll ave to look and see if there's a ground.
  • nnealnneal Posts: 72
    I doubt if oil would affect anything, although the cleaner the better. After having driven it some, are you still code free?
  • Yesterday I drove it to my buddies house and put the scanner on it and I had a code 13-VSS in the tranny and the code 24-TPS in the engine. And the night before we cleared the codes, but nothing has been showing up, also I took voltage reading on all the sensors from the scanner and they are around specs.
  • nnealnneal Posts: 72
    Still sounds like something isn't making a good connection somewhere. I assume all your fuses are ok. How is the PCM grounded? I looked at one schematic (link title), and it says the PCM provides the ground for the TPS and MAP sensor. That was on page 8w-30-4. Unless a component tests bad like the VSS, up to this point my guess is it's in the wiring or a bad connection or ground.
  • When my brother bought this jeep before I got it the powerwindows didn't work, so we checked for power to the moter and there was so we put a ground on the other and thats how they been working for the past year. On his 1990 jeep he had there was a fuse he found hanging down from the dash in line with a wire and needed a fuse so he used it and it shifted strange the next day, then he put that fuse back and it shifted great. Do you know if there is a fuse like that on mine and where, all the fuses I just looked at were good.
  • nnealnneal Posts: 72
    I don't recall any "inline fuses" under the dash of Chrysler products, although I could very well be wrong. It makes me think maybe it was a wire from an accessory someone added, like a radio or lights. But don't get me wrong, it could still be something Chrysler made with the Jeep.

    I'm still searching for other ideas.
  • rwengrrwengr Posts: 177
    Since initial inspecion of the trans was OK, I would be suspicious of the shift lever cable and make sure it is properly adjusted. Over time everything stretches and gets looser. You may think you are in drive, but you are actually 1/2 way between drive and neutral.

    My 97 jeep has a manual indicator which just shows you the position of the lever.

    I assume you have a manual indicator. If you have LCD indicator on dash, I am not sure how they work, but in either case, the cable may be the issue.
  • Saturday I checked the codes on my jeep and it had a code 13-VSS, so I cleared it and drove it sunday and now today monday. I just hooked the scanner up and I have a code 13-VSS. It tells me there is no signal. Now this is what controls my speedometer and that is working, when we unhooked that no speedometer. Any ideas. I think tomarrow if I have time I will take the sensor part off and see if it's defective. I'll keep you updated.
  • nnealnneal Posts: 72
    Found this page link title on Speed Sensors. It focuses on newer models with a note about earlier Cherokees.

    A few electrical diagrams I found on the web show the Vehicle Speed Sensor sharing the same circuit (or wires) as some other sensors. All three of them end up back at the PCM. If that is a code you keep getting after repeatedly erasing it, and you've checked the wires and connections (I know some are hard to get at), you might consider replacing that sensor. It's a 50/50 chance this problem is related to the head gasket job, so it's possible a problem happening at this time might have been a coincidence. One thing for sure, it's definitely a part that would cause those symptoms.
  • I have an 2006 Jeep Grand Cherokee with approx 33,000 miles. I moved my car this morning and there was a good size puddle of transmission fluid under it. Upon inspection it looks like the pan gasket is the problem, I checked and all the bolts are tight. Anyone heard of a gasket going bad so soon?
    I tried to check the fluid level and where the dip stick should be there is a cap that reads "For Dealer Use"
    Can I get one at any auto parts store?
    How much fluid does a grand cherokee take, the manual doesnt specify?
    How much torque do I use when putting the pan back on?

    Thanks in advance for your help
  • nnealnneal Posts: 72
    At 33,000 miles you shouldn't be having problems with any gasket. Is it possible a silicone type gasket was used by the manufacturer instead of a pre-cut one? I was surprised to hear some newer vehicles don't have a dipstick for the transmission. A few pages which discuss this and have some parts numbers are link title and link title (see page bottom). Two dipstick sources are link title and link title. Like you mentioned, I would try a local auto parts store first. Also, Googling "dipstick 8863B" brings up a lot of hits, although I'm not sure if that's the correct dipstick number for your Jeep. As for tightening torque, I only go slightly tighter than "wrist tight" using a srewdriver type handle with socket for older precut gaskets, but in your case I would try to obtain that information from a service manual or dealer.
  • My sisters vehicle has no dipstick, they want you to go to the garage and get it checked and have them do it. And I would do the same for torquing, just finger tight the snug them with a wrech or socket don't torque on them they break and leak, it works for me i have no leaks you should have no problem. My 95 I put in about 3.5 quarts almost 4, then checked if it was on the dipstick, but you should add a quart at a time then check it you have on the dipstick, then drive it, check it running and added if needed. Good luck!
  • Today when I drove it and parked, I cycled the key and it gave me VSS code and Governor Pressure sensor offset drift. My brother and I think you are right about the connection, but we think a ground, because of the ground for my windows going(still didn't find) and moving wires causes different things so. I'm going to a shop tomarrow where he gets his diagrams and get a ground diagram for all the grounds and whatever will help. And start here tracing wires (fun). I'll let you know!
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