97 Jeep Grand Cherokee Laredo keep dying upon ignition

check the map sensor

hey there,
we've already replaced the fuel pump... still having the same problem. The jeep broke again twice while I was driving to work on Monday. This time the check engine light stayed on and I was able to check the code. It was a 14, MAP sensor too high or too low. Took it to a little mechanic and he said he doesn't have the tools to check the ohmmeter readings... so we barely took the jeep today to another mechanic to see what the deal is. I'll keep ya'll updated.

I have a Wrangler TJ 4.0 that my dad got from a salvage yard. It ran fine when we first got it, but it had been wrecked. We got the body and everything fixed. When we went to start it it ran for a second and then died. It wouldn't start after that, only turn over. I went to a junk yard and got a pcm off of another 97 TJ and now it runs for a couple seconds and then dies. I'm in automotive classes in college and me, some of the other students, and my instructor have gone through it and can't figure it out. We called the dealer and they said it sounds like the vehicle theft security system. If any one else knows any thing it might be, I'd appreciate it.

Just check that the Fuel pump runs for a few seconds after switching the ignition on. Check for spark while turning the motor over. Check that the ASD Relay (if it's got one) hasn't been tripped. It's hard to know whats wrong without looking at it. But there's a few pointers. It could be the Anti-Theft. Have you got the remote keypad for the Vehicle?
After checking the above, get back to me..
Seeya.

'97 Grand Cherokee, 135,000 miles

Various warning lights
Power comes on at night
Instrument cluster & gages haywire
Stalling
Dead battery overnight
Feedback in speakers
Repeatedly blown 20A fuse on engine fuse block
Turns over, but now won't catch

Replaced: Ignition switch & ignition cylinder block, cam sensor, throttle position sensor.

Tried: new battery, unplugging PCM computer, checked all fuses.

And the alternator checked out all right.

Any ideas?...the dealer in stumped.

Here are the things I would check.

If the battery is going flat overnight, I would be checking for a shorted Diode in the Alternator Rectifier. The Alternator can still show that it's charging ok but the Battery would be discharging back though the Alternator. This can also cause power to be supplied back through the System. This can also cause the fuse to blow.

Check all Earth Connections from the battery to the Body and chassis.

Check all the connections at the mutlti plug under the dash. This can cause the guages and stereo to play up.

One thing that points to a bad earth is you say that you get feedback from the stereo. That sure sounds like a bad earth to me. Although, Low battery Voltage could also cause this problem.

You've probably tried this already, but, try fully charging the battery and put it back in the car and see what happens.

I hope something I've mentioned Helps with your problem.

Let me know how you get on. If I think of anything else, I'll let you know.
Seeya,

Help Please!
I have a GC Laredo 96 with about 170,000 miles
I also have many of the same problems as below to include:

-Gages acts like it's possessed
-Computer screen on/off
-Radio turns on by itself
-Headlights come on at night if the batter is not yet drained
-Battery drained after a couple days
-Stalls periodically
-Windows does not work

Please help or if you have any suggestions on what i should do.
I would like to keep if for another winter in Illinois

thank you very much.

check the map sensor it controles computer

RE: Haywire. If things act like they are possesed, try a new ECM (PCM). Replaced mine, fixed. They aren't cheap, and they need to match your vehicle quite specifically, so check the number on your unit when ordering. It's a 15 minute swap at most. OEM preferred, but they can be reprogrammed too. (Get one with a warranty, I've heard stories of people going through one or two refurbs before getting one that worked properly). Good luck!

Can you tell me where the ECM for the 97 is located? Took to shop they sd its the ECM and gave me the numbers to that ECM. How do I change this? Is there a way to test the ECM?

I HAVE 1997 JGC THAT THAT RUNS A FEW SECONDS AFTER STARTING AND CUTS OFF. STARTED AFTER PUTTING MY COMPUTER IN ANOTHER JEEP HAVING HAVING STALLING PROBLEMS. MY COMPUTER FIXED OTHER JEEP.SO WEGOT A NEW COMPUTER AND FIXED OTHER JEEP. MINE STILL NOT FIXED.

had computer flashed and fixed car
the anti theft had a glitch

Hi, I hope it stays fixed but for a glitch to be fixed by reflashing the ECU sounds a bit odd to me. I've now got a Diesel JEEP. I love the economy and the power is great from that little 2.5l motor. I see that this one has the I.D.Key system and apparently you can program the new keys to the ECU fairly easily.

So what you're saying is the car was running fine and then just out of the blue it started to run for a few seconds and then cut out? If that's the case it sure sounds like a security key problem was the culprit but I just can't get my head around why it would just do that out of the blue. Anyhow,I'm really happy it's going again and good luck for the future. Seeya.

I noticed that you have a diesel engine.
I have a '97 Diesel and was wondering if you knew whether I can take a engine wiring harness from a US produced gas model and replace. Are they the same?

As for jeep's running and stalling after a few seconds, my jeep is the same, however, if you have a remote to unlock doors, you must use this to disable the security feature, which basically cuts off the fuel supply after approx. 3-4 seconds. The car will start, but definitely cut off if the unlock button isn't pushed, in all cirucumstances e.g. even if car was already unlocked.

Hi,
Unfortunately the wiring harnesses are completly different. The Diesel has a lot of different features compared to the Petrol Equivelent. Just one example is the Glow plugs. Gas ones don't have 'em. My Cherokee has 2 ECU's also. One under the hood and one under the dash. The one under the Dash is for the Fuel Injector Pump.
Sounds like you have a weird problem. My 99 jeep has a transponder in the Key. The Ignition reads the key before it disables the Security System. I don't know how much different the 97 would be to the 99.
As a matter of interest, Why do you think your wiring Harness is at fault?

Hi, thanks for that info. My mistake earlier, mine is a '97.
The 2 reasons for thinking the wiring harness, my mechanic showed me some pretty nasty pics and of course the harness itself and secondly it started smoking about 3 days after getting it out of the shop. Hasn't worked for months.
Have to order the harness from Germany, unless you have any other suggestions?

Hi
This is alexhopes234,I have a '97 Diesel and was wondering if you knew whether I can take a engine wiring harness from a US produced gas model and replace. Are they the same?

As for jeep's running and stalling after a few seconds, my jeep is the same, however, if you have a remote to unlock doors, you must use this to disable the security feature, which basically cuts off the fuel supply after approx. 3-4 seconds. The car will start, but definitely cut off if the unlock button isn't pushed, in all cirucumstances e.g. even if car was already unlocked.
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alexhopes234
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actually that sounds right on. i'm gonna pay the 1/2 hour of labor at the dealer and do the same thing...b/c there was an update to the PCM software since they came out. otherwise, that refurb PCM i bought from that shady miami co. on e-bay is either sending me another PCM or the "tech" is gonna tell me where the phantom short or bad ground is just by cracking it open. huh? is that possible or are they gonna try to sell me something else? i'll sign back in when i get a helpful update. and p.s. - i've tracked this problem all the way back to the year 2001 on other boards. so, lets see...started several years after the internet got big, and no one has ever solved it and 2005/6 chrysler owners are still posting the same glitch. hmmm, sounds fun. again...the best advice still stands - fix it and sell it.

Hi, trevTaylor, You mention in your previous post that the 20A fuse kept blowing. Flashing the ECU won't fix that. Did you ever find out what was causing that? Also, the radio, did you find the problem with that Also?

PCM i bought from that shady miami co. on e-bay, dont trust that company i paid for a new pcm from them 300 dollars, when i got it , it was a old rebuilt , and thay wont give me back my money , i sent it back and its been 2 months now and no refund , please dont buy from thismiami base co, on ebay there crooks

Caught your post and wanted to chime in... Hate to tell you but they are all old PCM's at $300.00 that are reflashed... new ones start around $700/$800.00 from Jeep... If you don't believe me... stop and read all bloggs from many different sources... It's all the same story.

Now is the time to bend over and say thank you and can I have another one please... They got us coming and going!

before finalizing... make sure they match your needs to your car... read other posts... Vin # ETC...

good luck!

i bought the pcm from this dealer in miami sold on ebay , by the bigest dealer on ebay a brand new pcm he advertised as new , and when i received it it was a old rebuilt, he said it was flashed with all of the data , of course it didnt work , it was just a old piece of junk , iam just warning every one not to buy the junk on ebay that hes selling , if he crooked me he will crooked you , i still haven got back one cent, the best thing when you have a major problem with your jeep is not to spend anything on it and just sell it to the junk yard , i spent thousands of dollars now and still wont start

I have a 96 JGC Limited with 116,000 miles. One morning it decided it wasn't gonna stay running after it started, I had to keep my foot on the gas to keep the idel up. It does this on /off after sitting all night, or having not been driven all day. It also started to re-set all electrical inside the Jeep, kinda like the battery was unplugged, also will not turn over, gives me a clicking sound like the battery or ignition is shot. I have had the battery tested and it is fine. I found I can by-pass this by turning the key in the on position 3 times before I start the Jeep and 9 times out of 10 it turns over fine and will run perfectly. I am gettign the run around with the fuel sensors, fuel pump, etc. It's frusterating to know all of us are having the same problem, yet when we take it somewhere no one knows what the problem is.

Nicole I have been having the exact same problem you described for months. After I received an oil change it stopped happening for about month and the problem is starting back up again. I would like to know if you finally had your problem resolved or still have the vehicle.

Another possiblity to a no-start/stalling solution is to check the ASD (Automatic Shut Down) fuse in the egnine compartment fuse block. This circuit has ALOT of things on it, such as fuel injection, O2 sensors, etc. If this fuse keeps blowing, take a look at the downstream Oxygen sensor (After catalytic converter) wire harness. Chrysler actually issued a TSB on this. The wire harness zip-tie/retainer is usually the piece that breaks,which causes the wire to contact the rear driveshaft, thus the wire's insulation rubs off and the wire grounds out on the driveshaft. I had a 1996 Grand Cherokee 4.0L in my shop a few months ago that was doing this. It took me 3 days to chase this problem down. The customer was on a tight budget, so I installed a new zip-tie and re-wrapped the wire harness with heat shrink tape, rather than install a new O2 sensor. Problem solved. My customer was happy, and when he brings the vehicle in for LOF's I check the repair, and it's still holding up. I hope this can help someone.

Would just like to no if u found the prob and got it fixed?

I had the same problem for almost a year no body could fix it I almost replace every part but my problem was the wires that connect to the pcm computer it got 3 wires connector my failing one was the closer to the engine o fixed temporary I stick in a piece of cloth very tie between this connector and the water container ang it rn great for a long time I couldn't
find this part no where but the junk yard. I hope it works for you . you got a start your vehicle and then move the connector with your hand to find out wish one is causing the problem if it doeskin star have some body else to start it while you move the wires connectors.

I have contacted jeep to let them know there are alot of people wi the same problem and that they should recall the parts involved. NO RESPONSE. My truck has beev in the shop for about a month this last time and been down about 4months. I'm sick of this.