FERM and any other Jeep guys......
 

I have a 99 wrangler 4.0 litre (same motor as the pink Jeep) and the check engine light will not go off, any suggestions. It has been going on and off for the last month on a few days off a week, on again for a few days off a week. Now it is stuck on.

Just put a brand new exhaust manifold on it Sunday. Trying to sell it and need to figure this out. O2 sensor?

Go to Harbor Freight and get a code reader, it's cheaper than making one misdiagnosis.
http://www.harborfreight.com/cpi/cta...emnumber=46030
A lot of things it can be, Chrysler products will have a check engine light on if the gas cap isn't tighened to at least one click.
If you still have problems, holler.

http://www.harborfreight.com/cpi/gifs/clear.gifhttp://www.harborfreight.com/cpi/gifs/clear.gif

so does the code reader come with a book to tell me what the code means? can i get something like this at advance auto?

Yes they come with the book as to what code is supposed to be, also in most repair books there will be a list of the codes. Be sure to cross reference both to see if they transtale to the same thing.
The auto parts store may be a lot more expensive.
If I'm not mistaken Advance may "loan" the reader.
So far the one from Harbor Freight has worked on every Ford and Chrysler products I've stuck it to.

Typically, the check engine light is set to come on after a certain mileage so you will take it to a dealer for an emissions checkout. There is probably nothing wrong with your Jeep.

I had 2 vehicles that did that at exactly certain miles, on one of them the EGR light would come on at exact miles.
After determining there were no problems, I just found the reset, reset them and off for another 10-20,000 miles.
This shouldn't be the case with this one.
Resetting one (now) without a code reader is as simple as disconnecting the battery for 12-24 hours. But the problem will show up again in a week or two if uncorrected.
Allright FERM, get over here!!

That is not the case here, I can assure you. After 92 no chrysler product used a maintence required system on them, and OBDII I believe is mandated NOT to have one. Go to AUTOZONE, they'll check it for you for free. On a 99 you may still be able to get the codes by the old key switch on off on off on off on(some take 3 on's and some take 4) self diagnostic in 2 second intervals and on the last on leave it there. On a 99 the odometer should read out the CHRYSLER HEX code, if it does I got the book to tell you what they are(or you can look them up on line as well). I don't think a 99 TJ will have an LDP, so a loose gas cap is probably not it. If the JEEP is running well with just a check engine light(after a cracked manifold), then chances are that it will be a cat efficiency code or downstream O2 sensor performance code. Only way to know for certain is to get the codes and go from there. CHRYSLER's OBDII is normally pretty spot on, so codes are normally a pretty reliable diagnostic tool.

Our 94 Caravan had the dash diagnostic.
I tried it with a couple of other newer vehicles and they just sat there, but then again, I haven't gotten books on the other vehicles.
Oh, the loose gas cap-check engine light, is the number one thing on the Pacifica.

so FERM, your telling me if i turn the key on and off 3 or 4 times the dash will tell me the code for the problem?

2000 or 2001 on would have the check engine light from the loose gas cap. CHRYSLER Called it the LEAK DETECTION PUMP(LDP), and it was a PITA! It would often times throw a check engine light just for the heck of it, CHRYSLER programmed the wrong variables into it in it's first year, and it would set the light in under 20 seconds, well it takes upwards of 2 minutes to pull the tank down under a vacuum. I HATED the LDP with a passion, unfortunately though I was the only one in the shop that was able to efficiently use the LDP diagnostic machine:nut:.

CY, if it has it, the check engine light will blink a number of times for the code or codes.
Code 13 will show up as the light comming on once then pause and then comming on three times quickly.
If you got it, be ready to write the code(s) down. We got the numbers if it works.

You can try it and see. I know my 97 did, and some of the 99's did as well. It only takes a minute to try and see. The main thing to watch for is the check engine light to flash, but the odometer should also give a digital read-out of the actual number if it will do it. I know on the trucks 99 was hit or miss wether it would do it or not. So your WRANGLER may be able to.

so ON and OFF....wait two seconds....on and off.....2 seconds.....on and off.....2 seconds......on then see if the check engine light blinks and look for a code number on the odometer??? think i got it.....give me 5 minutes and i will be back.....

well just tried it several ways 3 ons and then 4 ons, and no luck.....

did i do it right? do i have to start it or just turn the key on and off?

If that don't work, do it all within 5 seconds.
The book on the Caravan says 1989-95 just turn the key on but it was published in 1996 and may include newer models.
By the way, you're not cranking it up, just turning it on till the dash lights come on.

will my owner's manual tell me how to do it? or are you looking at a repair manual?

Either 3 on's within 5 seconds or just turn the key on.
If nothing then you may need a code reader.

Repair manual.
FERM, get back here!!

looks like FERM is gone...... tried the on off thing several ways and no luck. wish we had an autozone close. all i have is a advance auto. and several of the local repair shops i use said at least $65 to plug her in.

Go with the ON-OFF-ON-OFF-ON-OFF-ON. Make sure you go to run and then back to off, and do not start it. If you bump it to start you have to start over. But the cycling needs to be smooth, if you have any breaks in it it will not go into self diag. Just go through them smooth and steady and see if that works. If not then yours may not be capable of it. Not all the 99's will do it. AUTOZONE is still free, or you can pick up a cheap OBDII code reader at WAL-MART for under $50.

ok i will try again in a little while. the boss is wondering why i keep going outside.....lol. if it does not work i will get the code reader tonight at wally world and let you know in the morning what it comes up with.

THANKS:beer:

Chrysler Code Retrieval

Accessing Trouble Codes
96 & later are OBD2 & requires an OBD2 scanner.

Code retrieval can be accessed by the ignition key or by a diagnostic readout box(DRB).To obtain the codes using the key method,set the park brake,and put the vehicle in Park/neutral.
Some 95 and later OBDII vehicles, you may be able to retrieve OBDII codes with this procedure, if equipped with digital dash.

• Turn the ignition key ON,OFF,ON,OFF,and finally ON again(ENGINE NOT RUNNING)
• The codes will start to flash on the POWER LOSS or CHECK ENGINE light.
• FLASH,pause,FLASH,FLASH=code 12

Clearing Trouble Codes

Diagnostic trouble codes may be cleared by disconnecting the battery ground cable for at least 20 seconds.
OBD2 vehicles require a scanner to clear the trouble codes.

this may help look threw this site

http://www.troublecodes.net


Here's the codes for your Jeep

http://www.troublecodes.net/chrysler/jeep.shtml



.

thanks Skools, but the key thing did not work again. I have disconnected the battery and I will let it sit for a few hours. We will see it that clears it.


Missed you around here buddy...glad you are back:party::fam:

Yep, like the instuctions SKOOLS posted, it don't work on all of em unfortunately. I know when I was at the dealer it would get frustrating waiting on the DRBIII to read codes, but the key trick didn't work but half the time(if you were lucky).

well i just reconnected the battery after an hour and the light is OFF:fam::happy::sun:and it better stay that way:bat::bat::bat:

I give it less than a week. If you drive it almost every day.

If the light is off after a reset, then start it up. If the light doesn't come on right away then you have a problem in an OBDII monitored area. Many codes will not set until you drive it for 20 minutes at highway speeds.

i figured it will come back on.....hopefully not until I sell it:sly::zip:

Will The Check Engine Light Come On If It Is Low On Fluids Such As Transmission, Transfer Case, Power Steering, Brakefluid?

Don't think that is the case on Chrysler products. However I do know that Honda will do it. The windshield wider fluid can be low and it will set the light off.

If the tranny was low it could throw a code for slippage. As far as actual fluid level's, that would be a no. Brake fluid though will turn on the brake light in the cluster as the proportioning valve will trip the limit switch if it gets low or air in it. Reading the codes is really your only option to go with. Be careful though of the light when trying to sell it. If it is an OBDII readiness monitor that is throwing it, it will trigger the light after a highway drive. MOST codes will clear themselves after 3 consecutive engine heat cycles without the fault being present. The downstream O2 is famous for driving people nuts with an intermittent check engine light. I don't remember where the ground is at on a 99, but I know they give trouble with the ground for the downstream O2.

well boys.....i took the battery cable off last week for an hour like I mentioned and the light is off...... I have driven it 55 miles and started it at least 6 times since then......I think I won:sun:

well stopped at autozone and the check engine light is due to the throttle position sensor and a loose gas cap or vacuum line. looks like some good old WD-40 should fix the first problem (throttle has been sticky lately), and the second should go away if i tighten the cap a little more......at least i know what it is now

TPS is sealed, so I doubt spraying it down will help any. Replacement is about the only option on them. As for the other code, are you sure it was for a loose gas cap? Did they give you the P codes? The idiots at autozone once tryed to sell a buddy of mine a distributor for a shift solonoid code. Like I said earlier, i don't remember 99 having a leak detection pump. It was probably a fuel vapor purge solonoid code which is not an uncommon failure item. Always check what the P code is, don't trust the AUTOZONERS to tell you what is wrong. Get the code and check it yourself. I use em just to get the P codes and then go and figure it out from there. I'm to cheap to spend the money to get a scanner when I don't check but 3 or 4 OBD2's a year as all of my stuff is ancient.

Does your gas cap have a warning on it in regards to if you leave it loose it may turn on a check engine light?

Be sure and wipe the thick varnish from inside the butterfly location of the throttle body. Laquer thinner or WD40 should take it off, that will slightly improve idleing and takeoff.

autozone printed out the codes for me. the gas cap was #123 (or loose vaccum line) and the TPS was #455. cleaned up the cable and throttle body and sprayed her down with WD40 and i think it worked. the trottle is no longer sticking like it was. as far as the gas cap. when i replaced the exhast manifold last week I missed a vaccum line when i put her all back together.:zip::nut:

light is still off but who knows

#1 I'm going to ASSume that the codes were P0123 and P0455? And #2 I'm going to assume that you got the codes reversed? If this is correct then the P0123 is for an open circuit in the TPS that allowed more than 4.50 V to be present at the sense circuit in the PCM. This would be a sure sign of a loose connection at the TPS, a bent prong inside the connector, or a failed TPS. The P0455 is for a large leak in the EVAP purge circuit. It says that yours uses a basic LDP with a vacuum switch and the purge solonoid to supply the pumping. Trace the large heavy guage vacuum line under the hood that runs over to a black solonoid. The vacuum line at some point will have a green test port cap on it, and it should tie into your vapor cannister which is a rectanguluar plast canister that was mounted under the hood on the passenger side on alot of them.

Ferm you are right on all accounts got the numbers mixed up sorry. well she is still acting up choking, stalling, spitting, sputtering. I am going to get a new TPS at advance today (if they have one) and put it on tonight. Looks like it is only two screws. pretty sure i got the vacum line thing taken care of. like i said i forgot to put one back on.

thnks:beer:

My check engine light has been on for about 2 years so I keep checking the engine and its still there.

You'll need to do a reset on it after replacing the TPS, so disconnect the battery for at least 30 minutes after replacement.