Jeep Grand Cherokee died suddenly at 50 mph

blanblanblanblan Member Posts: 7
edited September 2014 in Jeep
Today I was driving along at 50mph in my 2002 Jeep Grand Cherokee Laredo 4.0L when suddenly it felt like I lost half the power. A few seconds later the engine died. I coasted to a stop and was able to restart the engine numerous times. It would idle fine but as soon as you gassed it the engine would start misfiring again, sputter and stall. It did this a few times and now it won't even start at all.
I did the key trick and received 5 error diagnostic codes:
P0340 Camshaft position sensor circuit malfunction

P0351 Ignition coil A pri/secondary malfunction
P0352 Ignition coil B " " "
P0353 Ignition coil C " " "

P0455 Evaporative Emmission Control System Tank Detected (gross leak)

I believe the the P0455 was present before this cut off. I think that code is due to an aftermarket gas cap.

The other four codes are what have me concerned. Can anyone offer any ideas as to what would make those codes all come on at once? Seems odd that all coil packs would fail simultaneously.

Where should I begin? At first I suspected a fuel filter, but now after seeing the codes I don't think that is it.


  • blanblanblanblan Member Posts: 7
    Today I inspected the camshaft rotor sensor. I couldn't understand why Jeep would build a vehicle with the wire connection jammed up against the block. I noticed some metal shavings just below the sensor. I put 2 and 2 together and realized that the piece that holds the sensor (maybe called rotor?) had spun about 1/4 turn. I asked someone to watch the small rotor under the camshaft sensor to see if it spins when I bump the engine over and it does not....CRAP! I pulled out the rotor assembly that goes down into the engine block and I find a seized rotor with large metal teeth that have sheared off into my engine somewhere. Has anyone experienced this before? I am assuming that this means I have to drop my oil pan to at least fish out the metal teeth. My other concern is that the teeth on the other end (in the engine) may be damaged as well. PLEASE HELP!
  • tuggajbtuggajb Member Posts: 646
    not to worry bout cam not turning has chail to drive cam
    sound as if distrubator has frozen
  • blanblanblanblan Member Posts: 7
    Is it still called a distributor on the cam sensor rotor doohickey? This is an 02 GCL and has no other distributor that I can see (coil packs).
  • blanblanblanblan Member Posts: 7
    It looks as if it is called a camshaft synchronizer. It looks like a tiny distributor for the camshaft position sensor.

    I am hoping a Jeep tech will tell me the best way to go about changing this item out...mostly I want to know how I can be sure that whatever gear this connects to has not sheared as well. It is impossible to see from the top.
  • tuggajbtuggajb Member Posts: 646
    more than likley didnot shear gear, from jeep service manual not any harder than dis to change only thing that is a bear is making sure that you have timed it right (they dont use a timing light with this but turn and adgust timing with the computer reader on the engine computer)
  • blanblanblanblan Member Posts: 7
    Is this the type of thing that I can get the timing close and the computer will take up the slack or is this a dealer only timing fix?
  • tuggajbtuggajb Member Posts: 646
    prob dealer only as computer has to have the timing real close to even stare (sure not like the olden days )
  • blanblanblanblan Member Posts: 7
    I managed to fish out each piece of metal teeth by removing the oil pan. Can anyone tell me how the camshaft synchronizer is put in mechanically...meaning how (where) should the gears line up? I realize that it has to be fine tuned (timing) by the dealer, but I still have to get it somewhat close mechanically because you only have so much rotational adjustment. I can't see any timing marks anywhere. My best guess by looking at it is to maybe put the engine at TDC for the #1 cylinder and install the synchronizer with a "set pin" in the small hole (in the side of the sychronizer). Can a Jeep expert confirm this for me? SOS PLEASE HELP! I am desperate here and I think I'm the only guy on the planet whose sychronizer seized up. Even the Jeep dealer sounded baffled.
  • blanblanblanblan Member Posts: 7
    I got my 02 Jeep Grand Cherokee running super again. I'm sorry to say that forums were of little help but that is why I'd decided to post a how-to for others who experience this problem (seized camshaft synchronizer). There was very little help anywhere with this problem, so it is no offense to this particular forum. Obviously if teeth broke of of your synchronizer down near the oil pump drive you are going to have to get those out of your engine somehow before continuing.
    Now for how to replace your camshaft synchronizer. If your vehicle was running when this device seized, then you have lost the timing relationship between your cam and the camshaft sychronizer. In order to get it back you first need to get your #1 cylinder to TDC (top dead center) of the compression stroke. If you aren't sure how to do that, then you probably shouldn't be attempting this job yourself.
    When you purchase a new camshaft synchronizer you may or may not notice a temporary plastic set pin which passes through the aluminum casting into the small rotor (on the top part of the casting which stays outside the block). If it is not there, you will have to put something there to keep that position. I used a small piece of scrap 12 gauge household wire.
    The goal is to put the new camshaft synchronizer into the block so that it ends up with the position sensor wire connection facing straight back towards the firewall at 0 degrees from the block (basically straight back towards the oil filter). This may take you a couple tries since the gear on the synchronizer that meets the gear on the cam itself match up diagonally. This means you have to start farther counter clockwise from your ultimate goal of 0 degress and rotate clockwise as you push it into place. You may also have to move the oil pump slot a couple times with a long screw driver to line it up. When you get it to seat fully with the wire connection straight back, #1 cylinder at TDC (compression stroke) and temporary set pin in the camshaft synchronizer, then you have finished the hard part!
    At this point, I replaced the hold down clamp which anchors the synchronizer, put the small plastic camshaft position sensor back on and reconnected its wires and removed my temporary set pin (wire). You may still have to bring it to a dealer to have the timing fine tuned, but if you get it right, you can drive it there. I could tell when I first started my engine that I was one tooth off (advanced). I just lifted the camshaft synchronizer up just far enough to spin (retard) it one tooth. On my second try, the engine sounded terrific. If you don't know the symptoms of timing being too far advanced or too far retarded, then you probably don't want to attempt this job because you could cause engine damage...especially if your timing is way too advanced. If you were truly at TDC on #1 cylinder, you should be good to go. If it doesn't start you may have to repeat the procedure. You may have been at TDC of the exhaust stroke instead of the compression stroke meaning you were 180 degrees off.

    Hope this took a great deal of digging to get the right instructions.
  • tidestertidester Member Posts: 10,059
    it took a great deal of digging to get the right instructions.

    And that is probably why more help was not forthcoming so that makes you a pioneer! (I didn't say trailblazer or pathfinder!)

    Seriously, though, consider writing up a guide (see link at top of this page). Eventually, someone else is going to come looking for that same information.


    tidester, host
    SUVs and Smart Shopper
  • tuggajbtuggajb Member Posts: 646
    you got it right
  • heeplyheeply Member Posts: 3
    I've got a 96 GC Limited with 212k miles on it. Until Thursday it ran great. Now it won't start. I'm getting code 11 and the Chilton's manual says 'Camshaft signal or Ignition signal - no reference signal detected during engine cranking'. A friend of mine (who is also a mechanic) told me that I need to replace the camshaft position sensor. He also told me that it is sometimes called a pick-up plate. I've been reading the forums but I'm only finding info about the Camshaft synchronizer. Now I'm more confused than I was before.

    My first question is this: Is the Camshaft position sensor the same as the camshaft synchronizer? If my local parts store doesn't have a listing for the CMP sensor but does have the pick-up plate, will the pick-up plate work for me?

    I love my Jeep but it is getting old and it's got a lot of miles on it. I want to keep it but I don't want to go broke fixing it. Is it likely that changing this part will fix the problem or only lead to more problems?

    Any info would be greatly appreciated.

    Heeply Jeeply
  • cbushcbush Member Posts: 1
    hello. I am having the same problem with my 1999 jeep i thought it might have something to do with the chip in the key but i don't know. if you find out the problem let me know.
  • weewee Member Posts: 3

    i have a 2001 jeep grand cher 4.0L and was having trouble starting.

    i did the key trick and got code for crankshaft position sensor,i replaced and truck started right-up.

    now while truck is idling it stalled so i did key and got code p0351,p0352,p0353 ignition coil primary dwell time. I replaced ignition coil pack and truck is still running ruff,after replacing coil pack code p0351 went away but p0352,p0353 are still showing and truck keeps stalling.

    i went online to try to find some help could find anything. the code reads dwell time if theres anyone who has had this problem could you help please anything will help
  • weewee Member Posts: 3
    hello blanblan,

    i read your post and agree with you that this forum has been much help,
    however you seem to have a good idea on what going on with the jeep.

    i have 2001 jeep gran cher and was having trouble starting it got code from key code was for crankshaft position sensor,changed c.p.s. and truck started right up.

    now truck is running ruff and will not idle keeps stalling did key and now getting codes for p0351,p0352,p0353 ignition coil changed coil pack and p0351 went away and truck still running ruff will not idle without stalling.

    code p0352,p0353 still showing i've taken all kinds of wrong advice from so called mechanics.i'm slowly learning that they've been wrong, changed spark plugs,fuel filter all kind of stuff and not one of them worked.

    i'm hoping that you may have some insight on what i could do or is this a job for the dealer.trying to avoid the costly repair tag that the dealer going to tack on please help anything would be helpful

    thank you;
  • ike21ike21 Member Posts: 14
    9 times out of 10 when your car GC is running rough like that. It is the Idle Air Control sensor. $30 at Advance Auto or $50 to 70 at Jeep dealer. Jeep was is better quality. When that fails then other sensors soon follow like Map sensor.
  • jeepmejeepme Member Posts: 2
    I own a '98 Jeep Grand Cherokee 6 cyl. IL, 2wd. (115,000 miles) and it keeps stalling (especially when it's cold). I'll start it up in the morning, back it out of the driveway, and it stalls (sometimes). Sometimes it'll start right back up...sometimes not?! I've spent a lot of money; taken it to two very respected auto shops here in town and still...nothing?! Not only can they find nothing won't even stall for them?! Can someone please help me figure out what the heck is making my Jeep do this?! HELP!!
  • rwengrrwengr Member Posts: 177
    My dad had a similar problem, but it was a Cadillac. I researched problem and found reports of loose ground wires. It turned out to be the cause of his problem. Before left his car at the dealer for them to use. Would work fine. He picked it up. Stalled before he got home. It was a couple of years ago so I can't remember more details
  • paradox1paradox1 Member Posts: 1
    I had a simular isues. I have a 04 jeep, and i thought it was just at a certian speed that it died off, but it latter would shut off on bumps, or at random times. I had to replace the computer on the car :mad:
  • slatzmanslatzman Member Posts: 6
    please help i think i might have same prob im going to keep this short dont know if you will get this.i have 99 jgc died while driving changed plugs ran fine for 1 trip engine light came on again ran like needed tuneup reset computer drives fine.but i have not had it out driving farther then couple blocks. afraid it will do it again did you reset your computer at first.
  • kevinatorchardkevinatorchard Member Posts: 1
    Crank positon sensors commonly fail. Check to see if you have spark at the coil. If there isn't spark then its a good indication your crank position sensor failed. Its abot $75.00

    The sensor has a plug on the driver side of the engine and the sensor bolts to the bell housing of the flywheel driver side. Its a pain to replace without a universal joint and 18" extension.
  • slatzmanslatzman Member Posts: 6
    we changed coil and crank position sensor drives like a brand new truck(whenever we reset computer)drives fine for a little while and then it does it is telling me to change computer i was wondering if there was a cam crank timing sensor if there is where is it located.truck is driving me nuts feel like i bought it twice.any help?
  • boveebovee Member Posts: 3
    I have an 04 jgc, when I go over bumps, the speedometer drops off, at low speeds, it will just stall, you had to replace the computer?, which one?
  • slatzmanslatzman Member Posts: 6
    my prob was solved the first mechanic put the crank sencer in crossthreaded spent alot of money to find that out sounds like you have a loose connection the computer we changed was the main computer had to program the whole thing again in the end we put the old one back in.good luck.
  • jeep_buiderjeep_buider Member Posts: 1
    if its not tripping the check engine light i am having the same problem and it has gotten worse i have no idea but have u found out why its doing it yet mine is also a 98
  • slatzmanslatzman Member Posts: 6
    the original mech put the crank sensor in loose took forever to figure it out but our new mechanic figured it out took him some time but he got it.check your sensor again
  • vfreenvfreen Member Posts: 2
    Help!!! I have been going through this problem since November. 3 shops and now with the dealer for the 4th time in a 6 weeks. No matter what the speed, the car will just cut off. Sometimes it starts right back and sometimes it does not. Any suggestions will greatly be appreciated.
    I have changed the cam shaft sensor, EFI module, fuel pump, plugs, wire, distributor, rotor button, battery and the pins on the computer connection. Did I miss anything. Now the dealer has a team working on it. Please send prayers :).

    Vfreen :confuse:
  • jcalcuttjcalcutt Member Posts: 2
    i have a grand cherokee and it is losing power have read it could be the crank sensor does one from a 2 litre petrol cherokee fit onto a 4 litre grand cherokee also can i swap the pcm over been looked at by a garage but they cant find any faults
    also how do you get the codes on them
  • john_iijohn_ii Member Posts: 1
    Have you resolved this issue yet? I'm having the same problem. I just had fuel pump and filter replaced but the car still dies randomly. Some days, I can drive to and from work (an hour commute) with no problem. Other days it just dies as I'm driving. After a few minutes, it starts back up and I continue my commute.

    It is not giving any codes and because of the randomness, my mechanic is not sure what is causing the problem.

    I have a '96 JGC.
  • jcalcuttjcalcutt Member Posts: 2
    no i still have the problem and guess what my mechanic says the same cant find anything wrong done the same as you changed the fuel filter and also the cat on it not look for any codes yet
    i guess it is a sensor playing up somewhere but i have know idea which one
    if you solve yours can you please let me know what it was
  • slatzmanslatzman Member Posts: 6
    check your crank sensor again ours wasnt installed right.didnt show any codes because when car wasnt moving it worked fine.the jgc have a 25 minute reset on computer or take off negative for a minute.if that doesnt reset your problem than it isnt in the email is slatzman at juno dot com.hope it helps
  • vfreenvfreen Member Posts: 2
    Hey John, I think that the dealer finally found it after four tries. It was the connections to the computer. They did replace the computer jsut to be on the safe side. The losse connects were shortening out the cracnk shaft sensor. I will follow up with you once I have paper work with their notes in hand. This was 6 month problem. Think it's over.
  • deb034deb034 Member Posts: 2
    I have a 2002 jgc that has been having starting problems and would cut off on me. I bought it new and have 74,000 miles on it now. Replaced the fuel pump, still had same problems took it to dealership 2 times and was told they did not know what was wrong with it, that it would not do it on them no codes were coming up. Been in shop more in the last 2 months than at home. I had the crank shaft position sensor replaced still had problems. Finally I took it to C & C Automotive shop and they found the problem to be in the wires in wiring harness. $ 600.00 job
    I called the shop today hoping to get my jeep back today. I was informed that after replacing the wires the computer in the jeep would not take the program codes that were necessary. They called Chrysler and found out my computer would have to be replaced also. ( there was a technical bulletin about this problem and that Chrysler would cover the cost of computer) here’s the problem they don’t have any in stock it will be mid May or June before they would have any. I hope this helps someone out there having the same problem ask your mechanic to check your wiring. I still have to pay the $ 600.00 for the wiring that has been replaced but Chrysler is paying for the computer
  • kattykatkattykat Member Posts: 2
    Help, the summer is here and my 94 4.0 6 cyc.Grand Cherokee has a starting problem when it gets hot outside. A short scenario my jeep runs great never any problems until the summer and warm weather arrives. I can drive it to a few places in the morning stopping and starting with no problem but then maybe later in the day say I go to a store park come back out 20 minutes later turn on the ignition and it will not start. The ignition will keep cranking but it will not start. If I pop open the hood to the engine, open the doors and wait 10 minutes it will start every time. But this is very irritating and frustrating to deal with. I have had it to the Jeep dealership 3 times for this problem and of course by the time they get around to looking at it the car will start. If any body out there has any suggestions to offer I would be very grateful since this has been a couple of years dealing with this.
    Thanks so much Kattykay
  • tidestertidester Member Posts: 10,059
    That might be a problem with the fuel pump. Or it could be as simple as a faulty gas cap. Try loosening the cap then try starting your Cherokee after you replace it.

    tidester, host
    SUVs and Smart Shopper
  • kattykatkattykat Member Posts: 2
    Thanks, I already know that it is not the fuel pump. So I quess I will try the gas cap.
  • gold_inlinegold_inline Member Posts: 1
    It just happened to me. I got the crank sensor replaced tonite and tomorrow will have the cam sensor replaced- they work hand in hand and operate by virtue of magnets to detect the timing and exchange of fuel and air to the engine. Expensive though.
  • jgcgtajgcgta Member Posts: 2
    Was also having this problem. Changed the crank shaft sensor, plugs & wires, ignition coil. What it comes down to are the connectors/connections that go into the PCM. There was a post on another board I read to zip tie (2 zip ties on each plug) the connectors to the PCM. Zip ties should go all around the backside of the PCM. I did this 3 weeks ago and no stalls. It's not a fix, but a bandaid that works.
  • henksuriphenksurip Member Posts: 1
    thanks for your instructions, hope this solved my 96 Cherokee too.. :)
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