Hi - I was convinced that my fuel pump was bad but right before replacing it I bypassed the fuel pump relay and checked the pressure and found out it was ok. Now it looks like there is some kind of electrical problem. The security system has come on during this problem but it doesn't stay on. I reset it with the key method on the tailgate. I am not getting any spark and it looks like there is no juice getting to the coil. The check engine light will not come on when you turn the key on either. I thought maybe the PCM was bad but I talked to a Chrysler mechanic who said they rarely go bad. He suggested checking the fusable links, and the crankshaft position sensor.

Does anybody have any suggestions? Does anybody know how or where I can get some test point information on the computer cable etc.???

Thanks!

Val

Well you were when thinking of the PCM, it is possible that the PCM is the problem.

The CHECK ENGINE light not coming on can only be caused by 2 things, CPS (CrankShaft Position Sensor) or PCM (PowerTrain Control Module).
- I would start with the Crank Sensor it is the cheapest and the most common of the 2.

I thought maybe the PCM was bad but I talked to a Chrysler mechanic who said they rarely go bad.

I'm not saying your problem is your computer but I would not agree with what Mr. Chrysler mechanic said either.

When I was getting prices to replace my PCM on one phone call after telling the woman my part number she says "oh yes that's a popular one we sell a lot of those" and then after some keyboard clicks tells me they are out of stock!

I would be nosing around that security system if I were you. There was a recent post about the purple box that has the beeper from the VIC in it. Someone replied that people yank them to keep the security system from arming when they lock their doors. The PCM is going to cut power to the coil if the alarm thinks you're stealing the vehicle.

You might try pulling that box and see if you can start the vehicle.

Yes the alarm would cut power to the coil to keep it from starting, but would not cause the CHECK ENGINE light not to come on as soon as you turn the key.

valhalla3, try this, turn the key to the ON position and leave it there for a few minutes, while watching for the CHECK ENGINE light. After a few minutes the PCM shoud get a signal from the CPS and illumimate the CE light and then you should be able to start the jeep.

When the CE light illuminates it lets you know that the Computer has run the initial diagnosis and everything checks out and will allow the engine to start, when the CE light does not appear it is because the PCM does not recieve a signal from the CPS (bad CPS) or the PCM doesn't think it recieves a signal from the CPS (bad computer/PCM). and after a few minutes the PCM recognizes the signal and will start. Not always the case will the CE light appear after 5 minutes or so, but most of the time it will.

Remember when replacing the CPS or the PCM to disconnect the battery before removing/replacing either part.

Thanks for the quick responses!


I was suspicious of the security system from the first day this problem started. During one of the initial crankings the engine sounded like the timing was off, you know like it was fighting against itself. Then the security system came on briefly (horn and lights)

That would make total sense that the PCM is cutting the power....

You were saying there is a purple box somewhere that you can disable or disconnect??? Would this be on a 93 too???


That's 2 for the crankshaft position sensor now. That's definately worth a try. Hey would a scanner report the problem? I might have access to one...


Thanks

Val

Thanks dksob81 (http://www.automotiveforums.com/vbulletin/member.php?u=227077) ! Actually I have left the key on for quite some time and the only light that comes on is the security light after a while. The CE light never comes on any more. It did when this problem first started and the engine would start and die instanly once in a while too then, but not now.

I'll try that again tomorrow and see what happens. You say about 5 minutes or longer???

Thanks! - Val

Thanks dksob81 (http://www.automotiveforums.com/vbulletin/member.php?u=227077) ! Actually I have left the key on for quite some time and the only light that comes on is the security light after a while. The CE light never comes on any more. It did when this problem first started and the engine would start and die instanly once in a while too then, but not now.

I'll try that again tomorrow and see what happens. You say about 5 minutes or longer???

Thanks! - Val

It should come on within 5 minutes, I would say.

Also might want to try to reset the computer, just for the sake of it, you might have some luck. Disconnect the negative battery cable, then turn the ignition key to the START position (with the battery disconnected) and hold for 1 minute, then reconnect the battery and disarm the alarm (unlocking one of the doors or rear ahtch), then see if the CE light comes on when you turn the key.
I don't know if this will do anything but worth a shot.

oo yea also, what you were saying about the timing might be off, this is kinda normal, I get this every once in awhile, like vapor lock in the engine. I think it is due to the starter getting weak and when you try to start it the engine is prolly at it's highest point of compression and the starter barely has enough power to turn it.....lol thats just my theory.

Thanks for all the advice... I'll try these things tomorrow... Yeah that could be it about the rough start. I've seen a number of things like that happen and it does seem like the starter can't over power the engine....

dksob81 (http://www.automotiveforums.com/vbulletin/member.php?u=227077) - You were telling me to try disconnecting the battery and turning the key to the start position and hold for 1 minute. Do you mean turn the key as if trying to crank the engine and hold it on for the minute???. Then turn the key off before reconnecting the battery I assume....

Yes this is right, turn the key as if you were going to start the jeep.

Hey - Well I tried all those things and nothing worked. When I left the key in the start position for about 15 minutes. I watched it up past 5 minutes but the CE light never came on. At first the ABS light and I think the brake light or something comes on but they both go out and at some point the security light comes on and stays on.

I reset the PCM via bat disconnect and holding the key in the crank position for 1 minute. After reconnecting the bat the headlights and taillights flashed but the horn did not sound like normally with the alarm system. I tried the key in the tail gate on/off but that did not turn off the flashing lights. I tried each door and after doing the front passenger door it went off but I'm not sure if that did it or if it just timed out or something. There was not difference. No CE light and of course it would not start.

So what do you think?

Thanks!

Val

Disco the battery and pull that purple box. Then reconnect the battery and see if that keeps the security system from arming.

Where is the purple box you are talking about?

Thanks!

Val

Dude, I just had the same thing happen on a Jeep that came into the shop. The guy was trying to blame my remote start. I noticed that his dash didn't all light up. Tracing things for 2 days led me to the crank pos. sensor. Swapped that out and it started right up.

Where is the purple box you are talking about?

Thanks!

Val

It's under the dash to the left of the steering column.

I would think if the crank sensor was bad it would throw an 11 code but I'm fully aware we are talking about a Jeep here.

I was interested to see this article. http://autorepair.about.com/library/faqs/bl651h.htm

The problem in this instance appears to be bad wiring in the door harness that was tripping the alarm system. We all know that the wring in these doors is suspect, I've had to replace wiring in my own. That might have relevance here.

Nope. Used a $3k Snap On Tech 2 scanner and it didn't show that as a fault. It did show a fault but I can't remember what it was. Whatever the code was, it was related to the crank senser or it was in with that circuit.

I checked all the fusable links in the relay/fuse box under the hood. All the fuses are ok. I also checked voltages and everything was ok except the Alt. Pwr 1 (60 amp) fuse socket showed no power. The Eng. Cntrl (30 amp) socket showed a very slight voltage which I thought was weird. There is still no voltage at the coil connector. I swapped out the auto shutdown relay too and that made no difference. When I put some of the fuses back in the security system had the lights flashing but no horn honking. The security light still comes on after a while when leaving the key on start. It stays on the whole time. Even after "disarming" the system.

I did not see a purple box under the dash to the left of the steering column. Do you have to take the dash a part to see it?

Would the crankshaft position sensor being bad cause all of this? Should I tow the freakin piece of crap to a cliff and then collect the insurance? (:D)

I think maybe purple is misleading, I thought mine was closer to a brick red and I suppose there wasn't much need to care what color the thing was since it's hidden under the dash. You should be able to track it down from the beeps it makes. Disconnect a light bulb somewhere. The VIC will start harrassing you with it's lamp out message and beep everytime it flashes the message. Locate the source of the beep. That's the box you're looking for.

I have never heard any beeping like you are talking about. By VIC do yo mean the LED display down in front of the shift that tells you your doors are open etc.? Mine is flashing right now from all the bat disconnects and stuff we've been doing. I do not hear any beeping though. That's just another thing that's probably wrong with this Chrysler piece of ...#$##@! Or does it only beep when you lose a bulb and that kind of thing?

Yup that display is the VIC. Vehicle Information Center. I know for sure it beeps for lamp failure but I think it will beep if you leave the headlights on and turn off the ignition. I'm not sure about door ajar. I de-beeped mine awhile back and don't remember all the things it beeped for but it drove me nuts with the lamp failure so I neutered it.

Carribeanzj said in another post that removing this box keeps your anti theft from arming so doing this will be an easy way to see if your problem is the factory security system.

I'm headed out tomorrow to do a little winter camping through the weekend and the batteries for the digital are on the charger. If I get a chance while I'm packing tomorrow morning I'll snap a pic under the dash.

Thanks bringselpup (http://www.automotiveforums.com/vbulletin/member.php?u=419902) I appreciate that!

Val vbmenu_register("postmenu_3952964", true);

I actually was able to talk to a Chrysler mechanic at a dealership. He seemed to think the security system is locked up and that I need a keyless entry remote in order to reset the system. I know the system has been whacked out throughout this problem and the tailgate no longer seems to work in turning it off.

He told me to jumper the pin sockets for the auto shutdown relay and see if I have a voltage to the coil. I did that and I do get a voltage, but it still will not start...

Someone was trying to help me with this problem at first and changed the spark plugs and distributor cap. I can only assume that the spark plug wires are going to the correct number in the distributor cap. Does anyone know the cylinder numbers/order and which wires go to which place in the cap? Is the number one cylinder the one towards the front of the car or the one closest to the firewall? I'm assuming the distributor cap has numbers inbossed in the plasitc on top...is that right?

Thanks!

Val

What year is your jeep and which engine do you have? So are you saying the engine cranks but will not run?

Also whoever said the Check Engine light is powered up by the Crank Position Sensor is wrong. The PCM energizes the Check engine light as soon as the ignition switch is turned to run for the bulb test.

I'll take a guess here that you have a 93 GC? Here's the test to check the MIL lamp...

Check engine indicator as follows:
Turn ignition switch to RUN position.
Jumper cluster connector terminal C5 to ground, lamp should light. If bulb is satisfactory, check for open circuit between C5 and PCM module pin 32. If satisfactory, replace PCM.

Thanks YtseJam454... What you said is what the Chrysler mechanic told also. Let me restate the whole problem:

Initially it started cranking more and more before it started. If before cranking I turned the key on and off until I heard the fuel pump relay buzz then it would start right up. This went on for several months. Then one day it started to crank but kind of fought against itself as if the timing was off and the security system came on for a few seconds and then went off on its own. From that point it would not start except for a couple of times it would rev up and die instantly. I tried the key in the tail gate to try to reset the security system. Once when I did that it started to rev up and died instantly again. At this point the check engine light still came on. I suspected the fuel pump was bad. I swapped fuel pump relays but it made no difference.

Someone was going to help me change the fuel pump but we jumpered the relay socket pins and the pump came on. There was also gas pressure at the little capped pressure check point as gas shut out when we pressed it. It still would occasionally start to rev up but die instantly. I don't remember the order we did all of the following but at some point the check engine light no longer came on and it would not rev up and die anymore. These are the things we did around the time this happened: replaced spark plugs, rotor and cap; turned the key on and off until the security system came on and tried to verify keying the tail gate would shut it off because this is when the tail gate stopped resetting the system; took the panel off the inside of tail gate to check the wires around the lock and to try to free up the lock mechanism as it had been very hard to turn the key since I got the car.

At this time when we turned the ignition on an off a number of times the security system would come on with the horn and lights. Also when you leave the key in the on position for a couple of minutes the security light comes on and stays on. We also finally realized there was no juice going to the coil.

I checked all the fusable links in the distribution box and they are good. I checked voltages and there was no voltage on the cable going to the coil. When I put the relays back in the security system came on but only the lights were flashing, there was no longer any horn. Using the key in the tailgate or any of the doors would not shut of the security system and it would just time out. The check engine light still never comes on and the security light still comes on when you leave the key on.

The Chrysler mechanic told me the check engine light is only a bulb check like you mentioned. He told me to jumper the pin sockets for the auto shutdown relay and see if I get voltage at the coil and if it would start. I did that and got voltage to the input side of the coil (measuring at the end of the cable that goes to the coil) but it would not start. I had no help so I couldn't turn the engine over and go look for a spark from one of the wires or plugs. He also said to get a keyless entry remote because that is the only thing that will totally reset the security system regardless of any problems with a door switch. Unfortunately I never got one with the car so I'm looking on Ebay for one. They cost way too much at the dealer...what a rip off!!!

I want to check for a spark today and I want to verify that the spark plug wires are connected to the right cylinders and distributor cap positions. I don't know which cylinder is considered number one though. I'm assuming number one is either closest to the fire wall and then sequential numbering to the front of the engine. Or number one is closest to the front of the engine and is sequential going towards the firewall.

OK so I have a 1993 Grand Cherokee limited with a 4 liter straight 6 engine. Yes...it will crank and crank but will not even sputter any more. Any different PCM will have to be programmed for this car correct? The Chrysler mechanic said you can't just go get any PCM. I'm assuming he meant you can't do that without reprogramming.

When you refer to cluster connector terminal C5, are you talking about the distribution box under the hood that has the fusable links and fuel pump, auto shutdown relays etc.??? How would I check for an open circuit between PCM pin 32 and C5??? Are you talking about a continuity check with a meter set on resistance? Or do you mean look for a voltage from C5 to pin 32 on the PCM where the connector would go? Zero volts meaning it's shorted to ground, 12 volts meaning an open circuit?

Thanks!!!!

Here's two pics that may help.

http://img.photobucket.com/albums/v437/randomguest/distcapfiringorder.jpg

Pics are a lot smaller here than they started out. In this picture taken from the pass side fender
left to right and top to bottom it's:

6 -2
3 - 4
5 - 1

And the box I was talking about under the dash.

http://img.photobucket.com/albums/v437/randomguest/beepboxunderdash.jpg

usually if it stats then dies instantly it's the alarm system . Thats the way its supposed to work But the CPS sensor hasn't been changed it could very be the problem. CPS sensors are jeeps biggest problem. Dale

Thanks Dale and to every one else that is responding here! I've heard a few people say it might be the crank shaft position sensor. I've also heard they are notorious for going bad but isn't everything with a Chrysler product... :)

I stopped at the Chrysler dealer today to let them no what happened with what they told me to do. They pretty much told me that I've been backed into a no win corner. They think it is the security system but heres the problem. They said it sounds like one by one each of the doors and now the tailgate switch has failed as each one should reset the system but none do now. The other problem is not having a keyless entry remote but even if I did it has to be programmed for my car and part of the process requires that the electric door lock/unlock work. As fate would have it, the door lock has never worked to lock the doors only to unlock them. So I would not be able to program the remote which means now that I am totally $%$##@#ed. Thanks to the morons at Chrysler with their idiotic brainless design my car has been rendered trashed just because there is no way to reset the security system. How dumb is that to design a security system that won't let the owner drive his car. Come on....who would want to steal a Chrysler product anyway.... :) Even the Chrysler guy said it would be extremely expensive because they would have to flat bed the piece of junk to their place which would probably be $200 because of the distance and then with all the diagnostics and having to fix the wireharness and troubleshoot the wiring in each door and posibly replacing the PCM and who knows what else.

Yes I'm in an extremely bad, defeated mood..... :frown: I hope someone out there has some ideas that might help. At this point I think I will be forced to get another cheap car and then over time try to fix one problem at a time to lead up to being able to reset the security system and then sell the piece of crap :)

Thanks!

2 things come to mind.

1) You said you've never heard the beep and haven't found the box. If it's missing because someone pulled it out your door locks won't lock and maybe that's your whole problem.

2) Get your hands on a PCM for your vehicle but with no theft. Swapping one is easier than changing your oil. But like Chrysler said you need the right one. You can't put a PCM from a 93 in a 97. But they are an over the counter parts item and even cheaper if you shop around. My PCM was $220 ( A Cardone Reman) at Advance Auto Parts after turning in the core. Try Rockauto they are even cheaper. www.rockauto.com

Most wire shorts have been tracked to the drivers side electrical boot h
housing.You can open door and pull boot back to check.
Chrysler just don't build JEEPS. Dale

Thanks for the information you guys. I'll have to look for that box more carefully. By the way thanks for the pictures. Can I get a used PCM off a 93 at a junk yard and then have it programmed?

Yes that wire harness boot gave me problems before with the back windows not responding. I have to move the door back and forth or wiggle the harness. Man I think Chrysler is rivaling Microsoft now for the crummiest, most inferior product that still makes the most money...:)

My Jeep has been down for over a month now and my friends won't be friends if I don't get there borrowed car back to them. I have some problems that are inhibiting me from being able to do some kinds of work on the car as well as not having the money to throw at it...

Please keep the ideas coming... and thanks again!

Oh yeah you're right... Chrysler builds CHEEPS not JEEPS....:)

Val

You don't need to program anything. Unplug the old one, undo maybe 4 or 5 screws holding it to the firewall put the new one in place and bada-bing your back in biz. Usually you just get a replacement based on the part number of the one already in there.

The dealer you talked to is going to want to sell you a $600-$800 oem PCM that's really no different than the one you will get via an auto parts store. You need to find a way to get someone to tell you what PCM part number you have by either looking at the sticker on your PCM or using your VIN at the dealer and then finding out what the number would be if your vehicle didn't have theft. That will be the number of the PCM you'll want to get your hands on. You can check on EBay once you have that number, maybe you'll luck out.

Were you able to get away without programming or having yours programmed??? Without theft I would assume once hooked up there is nothing to interface with any of the old security sensors so it should not be a problem.

I did luck out and won the bid on a remote last night on Ebay. I got it for $26. The guy had emailed me the programming instructions and from what I saw the electric door locks don't have to work. I'm going to try that first since it would be easy and the cheapest and since I already bought it...

I will start looking into the part number on the PCM too...My next questions might be about fixing the wireharness or at least try fixing one of the door switches so it will reset the system. Money is a problem right now so getting another PCM might have to wait anyway.

Thanks!

Val

Yeah the PCM is a total plug and play type replacement. No programming is involved. Disconnect your battery cables and then you take off the big connector. Detach it from the firewall. Hang the new one in place and plug her in. A 15 min no brainer especially if all you're doing is replacing with the same part number. You would be a bit more on the edge looking for a non factory theft PCM for a Jeep with factory theft but I can't see any reason this won't work. A recent post here someone else had the exact opposite problem as you. He had wound up with a PCM that had factory theft in it. It was causing his Jeep to act like yours. He got another PCM without theft and he was back running.

In fact PM me if you need to, he seemed to have a junkyard close by that had these things available and I wonder if the PCM he couldn't use is still there. Otherwise keep your eye on Ebay.

Well I got the remote. At first it would not program and I thought it was due to my electric door lock/unlock that will not lock the doors...only unlock. I kept trying and did finally get it programmed so I can unlock the doors with it. BUT....the $#$#@@ security system is still not reset. I'm assuming it needs to actually have the door do a full lock unlock cycle to reset or the PCM is bad or the security portion of it anyway.

Does anyone have any ideas from this new turn of events??? I'm still considering getting another PCM but want to wait until I have to because of the cost.

Val

I had your exact same problem last summer. I replaced the PCM and it fixed everything. If you're still having issues I'd give this a shot.

Hey - Thanks for the response! Really you had the same problem? Did the security light come on after the key was left on for maybe half a minute or so? And did your check engine light not come on anymore? I don't know if you saw those thins in my earlier posts. Also did you not have to program the PCM when you got it? Did you get a new one or a used one?

Thanks!

Val

My security light was coming on, so I disabled it by grounding it out. I'll try to find the how to on how to do it. That did not cure the problem though. My CE light would not come on for over 20 mins sometimes. I got a remanufactured PCM through www.rockauto.com. After the core was returned I think it was $140. All you do is take the old one out and plug the new one in. It took about 10 mins and no, you don't need to program anything. I couldn't get the Jeep started for over a month before. After I plugged the new PCM in and reconnected the battery it fired right up. If you decide to give this a try, remember to disconnect the battery first.

Did you get your PCM with or without theft/security? I just assume get rid of the security system because I can't imagine who would want to steal a Chrysler product anyway...:grinyes: And if it was stolen I would rejoice and go buy something else....:wink:

Thanks!

Val

I got the one with the security / theft. I didn't want to take any chances and went for an exact match.

my jeep did the same shit i put like $700 into and it ended up being the ecu i put all the senors i could think of crank shaft sen cam sen colant sen new coil it just wouldnt do anything the brain is worth a shot after u try other shit like i did but the way i looked at it is i would of payed that or more for a shop to tell me it was the ecu well good luck to

Thanks for the response.... So did you replace the computer/PCM? Is that what you meant by the ecu? And if you did replace it did that fix everything? Yeah shops are way over priced but not as bad as the legalized crime of the dealership....Thanks!

Randy

ya i replaced the pcm yes that fixed it is runs now just make sure u dont have any wires that will short out and frie it again thats what happen to me good luck

I got a 1994 and I think I have an alarm issue. My lights just flash, no horn. I just want to rip the damn thing out. And get me a real aftermarket alarm/start. Lots of good info here. So PCM with no alarm, or cps. Is what I will do first.

Thanks