LOST JEEPS :: View topic - Another limp mode

I am sorry, but there exists much needless confusion on this site about "Limp mode". Waaay long time ago, somebody started calling all trans and fuel issues "limp" mode and the misnomer stuck.

Limp mode always sets a code. A code scanner is a few bucks at harbor freight or checker or whereever. I would have a really hard time believing that limp mode was triggered and the check engine light (CEL) was not thrown. Anyway, if no code can be read with a scanner... it was not limp mode. If the computer for any reason disables power, it does so to protect mechanical equipment and always sets a code.

If there is no code set, this is likely caused by a lack of fuel.

It causes THE EXACT ISSUE described by the OP. I know because I have had it happen to me. I have had a batch of bio left in the tank for 3 weeks (I parked it and let it sit) that went bad... the result was first a little loss of power and some hesitation after heavy throttle... then as the filter became plugged with crap from the tank... this exact behavior. It would hardly go. Pull over, restart... good to go. Then it would rev fine but would not upshift. Letting off the fuel pedal caused "coughing and spitting". No Cell thrown, no codes set that could be read.

Changing the filter stopped my issues for about a week at a time... but the tank had sludge on the bottom of it now. After going through four filters in a month, I said to hell with it and dropped the tank and flushed a bunch of yucky sludge that had formed out of the bottom of it. All has been well since. Now I only add bio when I am going on a trip or driving every day. Take a fuel sample, change the filter.... but whatever this is, it is likely not a computer induced condition (not without a code set).

Author:	click23 [ Mon Jul 06, 2009 9:58 am ]
Post subject:	Another limp mode
Well it happened again, the last time it happened I had to have the transmission replaced: http://lostjeeps.com/forum/phpBB3/viewtopic.php?t=38297 My wife and I decided to take drive up to the mountains Friday night. We started off on The Dragon, US 129, and then up the North Carolina side of the Cherohala Skyway. This is about a 150 mile round trip. Well heading up the Cherohala Skyway on the NC side is pretty steep, maps, if click the elevation map on the bottom, we were heading right to left. The speed limit was 45 and I was trying to keep it there, but with some of the curves I would have to slow down. So I was running 2,000-2,500 RPMs at 30-45MPH. I slow down to go around a curve, and when I come out of it, I press the pedal down, and presto I have a limp mode. This happens some where between Wright Cove and Spirit Cove, did I mention that it is 10:30PM by now and I am along ways from cell phone coverage on a road that gets very little night time traffic.. I manage to make it to the Spirit Cove pull off. I let he cool down for 15 minutes and head back out. Still in limp mode, so I take it real slow, 20-25 =, and within 5 minutes it comes out of limp mode. No CEL or trans temp light. I think I got the transmission a little too hot, but I was not going that fast or high RMP. I have taken the Jeep up this way once before, but it was much colder out, but it was pretty cool Friday night 60ish. We are planing a trip next week to Charleston SC, and my wife is a bit worried, and so am I. I was planning on heading into North Carolina across I40 which is pretty steep, but then again I will have quite a bit more speed heading up it. What do you guys think? Robert

Author:	Joe Romas [ Mon Jul 06, 2009 11:01 am ]
Post subject:
What year is your crd. I read through the entire old thread and found no mention of it. If yours is a 05 did you notice the temperature guage rising? If so then it could be a bad fan clutch. Seems there were some bad ones released or a batch that failed early. Otherwise reread your other post and see what more then one user suggested. I'm only one person with one jeep but mine stumbled the day I brought it home from the dealer within one mile of the dealer. Of course I got the standard "can not duplicate" answer. You would think a company that cares would look into these "can not duplicate" failures for a cause Maybe that's why they are where they are now It was air in the filter head and I cured it by putting in a lift pump. What good is a warranty if they don't fix it untill it melts down and turns blue Our CRD's were a market test and more then a couple owners dumped them early on after seeing the light. That is there will be little support from Chrysler for CRD owners as they have bigger problems. Maybe it's time to move on

Author:	click23 [ Mon Jul 06, 2009 11:04 am ]
Post subject:
It is an '05, the temp gauge did not get above the half way mark, and I have had the SB performed for the faulty temp sensor calibration. I do have an extended warranty for about another 20,000 miles.

Author:	gmctd [ Mon Jul 06, 2009 11:23 am ]
Post subject:
Sounds like insufficient fuel supply, a common problem - or could be fuel overtemp, where ECM pulls fuel until inlet fuel temps come down - also can happen if you're a two-footed driver, not taking yer left foot off the don't-go pedal B4 you mash the go pedal..........................

Author:	Ranger1 [ Mon Jul 06, 2009 11:23 am ]
Post subject:
If you're going to rely on the warranty, better ask the dealer for a solution.

LOST JEEPS http://www.lostjeeps.com/forum/phpBB3/

Another limp mode http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=44779	Page 1 of 2

Author:	Joe Romas [ Mon Jul 06, 2009 11:26 am ]
Post subject:
click23 wrote: It is an '05, the temp gauge did not get above the half way mark, and I have had the SB performed for the faulty temp sensor calibration. I do have an extended warranty for about another 20,000 miles. Go outside, raise your hood and start the engine. Then back outside and listen to the engine. IF IT DOES NOT SOUND LIKE A TORNADO then the fan clutch most likely is bad. Another member here ownes both a 05 and 06 and has a long step driveway. He had problems with the 05 overheating going up his drive but not on the 06. After replacing several parts and not solving the problem another member arrived to help him out. He/they determine the fan just was not doing it's job. Listening to both showed a big difference. Also since yours is a 05 it definetly should have had the torque converter replaced on the f37 recall. Part of that was to listen for a knock, indicating the torque converter had already started to dump, and if so replace the front pump AND TRANSMISSION COOLER/AC condensor also. Now if they didn't your cooler could be partially plugged from broken parts of the first TC. That could explain your first transmission turning blue. Now you've got to convince your dealer there is a problem. Good luck even with your extended warranty. I have one too but wonder just what it's worth. I prefer used cars where the only warranty is what I provide but we can't always get what we want. Pulling our 17' travel trailer through NC last month my temperature guage never even got to the half way mark. It was a tad below half way just like it always is.

Author:	Ranger1 [ Mon Jul 06, 2009 11:51 am ]
Post subject:
Quote: Good luck even with your extended warranty. I have one too but wonder just what it's worth Agreed. I too purchased a 7 year, 70K bumper to bumper Chrysler warranty. 2 torque converters, 2 egr valves, 2 sets of ball joints, 2 failed fuel heads later, I have an approximate idea of what it's worth to me. I couldn't afford to rely on my extended warranty. That's why I say if you're going to rely on warranty, its up to the dealer. Almost all of the successful fixes on this site require owner intervention in the form of their own money and time. The dealer won't install most of these known fixes under warranty, the newer design fuel head being the lone exception I know of.

Author:	BlackLibertyCRD [ Mon Jul 06, 2009 12:01 pm ]
Post subject:
I vote for air in fuel or semiclogged fuel filter. Lack of fuel would seem like limp mode. The lift pump mod is one of the best thing I did to my CRD.

Author:	Joe Romas [ Mon Jul 06, 2009 12:04 pm ]
Post subject:
Ranger1 Mine just went out of the 36/36 warranty in May. Before that the window channel fix for both front windows was close to $600 billed to Chrysler and the EGR and FCV's on another trip were around $700 billed to Chrysler. There was a tsb on the windows and the FVC whinned for 5 minutes on shut off and there was a cel for the egr so they had something to see Two trips and about $1300 warranty claims Does Oboma and Fiat know what they're in for

Author:	click23 [ Mon Jul 06, 2009 12:57 pm ]
Post subject:
I am pretty sure it was a limp mode. It was not a lack of power, it just would not shift above 2nd or 3rd gear. When I would let off of the accelerator, the deceleration was not smooth, like the engine was tied directly to the rear end, torque converter locked up in second or third? This is exactly what it did back in December. The fuel filter has about a thousand miles on it and the torque converter was replaced under F37 and 7 months ago when the transmission was replaced. I will check the fan clutch and see if there is any air in the filter.

Author:	linewarbr [ Mon Jul 06, 2009 5:46 pm ]
Post subject:
Limp mode would also produce LOTS of black smoke and a CEL.

Author:	nursecosmo [ Mon Jul 06, 2009 6:49 pm ]
Post subject:
linewarbr wrote: Limp mode would also produce LOTS of black smoke and a CEL. No it won't. Not unless one of the CAC hoses is burst.

Author:	nursecosmo [ Mon Jul 06, 2009 6:57 pm ]
Post subject:
click23: from your description of events, it sounds like either an air leak or clogged fuel filter. It makes no difference if you have a new filter or not, because you can never predict when you will get some bad fuel or have a growth of algae spring up. If it was one of these problems which only showed up under heavy fuel demand, and it dissapeared during normal use, the dealer would not be able to pull a code, because the code clears itself after 3 normal start cycles. It would be a good idea to carry a cheap scanner with you for the next time.

Author:	Joe Romas [ Tue Jul 07, 2009 8:13 am ]
Post subject:
click23 wrote: I am pretty sure it was a limp mode. It was not a lack of power, it just would not shift above 2nd or 3rd gear. When I would let off of the accelerator, the decoration was not smooth, like the engine was tied directly to the rear end, torque converter locked up in second or third? Looking in the FSM for the 05 there are 3 forms of transmission limp modes Reading up on them may help you. See: 3.2 FUNCTIONAL OPERATION Also there's "Driving" relearn procedures you can do for different shifting problems. See: 3.2.1 DRIVE LEARN PROCEDURE – 45/545RFE It also says the tcm stores codes for 40 warm up cycles. So unless you've driven more then 40 warm up cycles the codes should still be there for your dealer. The FSM for the 06 does not seem to go into as much detail I don't know if any of this will help but at least you'll be more informed Joe

Page 1 of 2	All times are UTC - 5 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/

Author:	nursecosmo [ Tue Jul 07, 2009 11:26 am ]
Post subject:
Well, Click, if you will recall from your first thread which you started in December, you had some serious air problems which you apparently never addressed. many of us were of the opinion that you needed a lift pump. The probability that your problem is originating with the transmission is infinitesimal seeing as how you have a brand new one and still have the same issue. An air in fuel originated limp mode will not always cause a CEL. I have had my own CRD go into limp from AIF without the CEL. I would bet money that your problem is related to air. Why not install a cheap inline shuttle pump? (less than $100) You have nothing to loose because you already know that you are getting air in the fuel head, and if this current problem is not related to air in fuel, at least you will not have future aif issues.

Author:	click23 [ Tue Jul 07, 2009 2:05 pm ]
Post subject:
Joe this defiantly sounds like number three "Logical Shutdown with Recovery" The TCM does not de-energize the Transmission Control Relay. Instead, the transmission will utilize 1st and 3rd gears while in ‘‘D’’, and will use 2nd while in ‘‘2’’ or ‘‘L’’. All transmission operation in this mode will be at a preset line pressure (open loop). The transmission will resume normal operation (recover) if the detected problem goes away. Three recoveries are permitted in a given key, after the fourth occurrence the operation described above will be maintained. After doing some research here, I think it was either fuel pressure fault or the transmission over heated that caused the limp mode. I will check the filter for air tonight and order a new one.

Author:	geordi [ Tue Jul 07, 2009 2:16 pm ]
Post subject:
Click, LISTEN to NurseCosmo. The situation you are describing is very similar to my own experiences with air in the line AND has not happened since I installed a Mr Gasket fuel pump next to the tank. Replacing the filter will probably help, but mostly b/c you will have to re-prime the head to start it again. Having a positive pressure fuel line will make your life a LOT easier.

Author:	Pablo [ Thu Jul 09, 2009 12:58 am ]
Post subject:
I am sorry, but there exists much needless confusion on this site about "Limp mode". Waaay long time ago, somebody started calling all trans and fuel issues "limp" mode and the misnomer stuck. Limp mode always sets a code. A code scanner is a few bucks at harbor freight or checker or whereever. I would have a really hard time believing that limp mode was triggered and the check engine light (CEL) was not thrown. Anyway, if no code can be read with a scanner... it was not limp mode. If the computer for any reason disables power, it does so to protect mechanical equipment and always sets a code. If there is no code set, this is likely caused by a lack of fuel. It causes THE EXACT ISSUE described by the OP. I know because I have had it happen to me. I have had a batch of bio left in the tank for 3 weeks (I parked it and let it sit) that went bad... the result was first a little loss of power and some hesitation after heavy throttle... then as the filter became plugged with crap from the tank... this exact behavior. It would hardly go. Pull over, restart... good to go. Then it would rev fine but would not upshift. Letting off the fuel pedal caused "coughing and spitting". No Cell thrown, no codes set that could be read. Changing the filter stopped my issues for about a week at a time... but the tank had sludge on the bottom of it now. After going through four filters in a month, I said to hell with it and dropped the tank and flushed a bunch of yucky sludge that had formed out of the bottom of it. All has been well since. Now I only add bio when I am going on a trip or driving every day. Take a fuel sample, change the filter.... but whatever this is, it is likely not a computer induced condition (not without a code set).

Author:	nursecosmo [ Thu Jul 09, 2009 2:30 am ]
Post subject:
Pablo wrote: I am sorry, but there exists much needless confusion on this site about "Limp mode". Waaay long time ago, somebody started calling all trans and fuel issues "limp" mode and the misnomer stuck. Limp mode always sets a code. A code scanner is a few bucks at harbor freight or checker or whereever. I would have a really hard time believing that limp mode was triggered and the check engine light (CEL) was not thrown. Anyway, if no code can be read with a scanner... it was not limp mode. If the computer for any reason disables power, it does so to protect mechanical equipment and always sets a code. If there is no code set, this is likely caused by a lack of fuel. It causes THE EXACT ISSUE described by the OP. I know because I have had it happen to me. I have had a batch of bio left in the tank for 3 weeks (I parked it and let it sit) that went bad... the result was first a little loss of power and some hesitation after heavy throttle... then as the filter became plugged with crap from the tank... this exact behavior. It would hardly go. Pull over, restart... good to go. Then it would rev fine but would not upshift. Letting off the fuel pedal caused "coughing and spitting". No Cell thrown, no codes set that could be read. Changing the filter stopped my issues for about a week at a time... but the tank had sludge on the bottom of it now. After going through four filters in a month, I said to hell with it and dropped the tank and flushed a bunch of yucky sludge that had formed out of the bottom of it. All has been well since. Now I only add bio when I am going on a trip or driving every day. Take a fuel sample, change the filter.... but whatever this is, it is likely not a computer induced condition (not without a code set). Actually this is not altogether correct. I have definatly had "limp mode" occur without the computer tripping a CEL. I don't know why the ECU would cause a limp mode without a CEL or DTC because it goes against all conventional wisdom about ECU functioning, but then again, there are many things about the CRD which go against conventional wisdom. I have had it occur from a plugged fuel filter the same as you, but the CEL didn't show up until 3 or 4 occurences of the limp happening while driving. It would be triggered initially by fuel starvation under acceleration up a hill, with a stumble or two. If I let off of the accelerator so that it could get enough fuel but still kept it in high gear, the drivability remained fine, but as soon as I dropped down into the lower range, the limp feature was initiated and I had to wind up almost to redline, then back off the accelerator, in order for it to shift up. After restarting it the limp would clear until the next time it happened. after doing this several times at will the Cel came on and the scanner could read a P0093 DTC. Untill the CEL was thrown, there was no DTC shown on the scanner. I have also had the same power loss from a restricted filter which you described, a couple of times but it didn't trip the limp mode or CEL on those occasions for some reason. On another occasion it started missing really badly shortly after plugging the MAF in after several months of running with the ORM. It went into classic limp mode with the impaired shifting, again with no code or CEL. After restarting it ran fine the rest of the morning, but did it again that afternoon, but that time it lit the CEL and gave me a 0401 EGR code along with another I had never seen, I don't remember the number but it said "random engine miss". My theory was that the EGR stuck open and caused the miss. After a good hot Italian tune up, it never did it again. Both of these occurences were definetly limp modes which were ECU induced and happened without the CEL being tripped. Strange as that may seem.

Author:	Pablo [ Thu Jul 09, 2009 4:11 am ]
Post subject:
Really stupid setup they have on the electronics on this thing, no doubt. But I think we are giving it more credit than it deserves. Even if it had no electronics and a regular dumb slushbox, I would not expect it to upshift right when the torque specs are low due to fuel starvation. Even when I had fuel starvation issues, I could rev it high in neutral-- as there was no load on the motor. But revving with a load is a different story. With no torque output it is not going to hold a higher gear against a load, so it stays in a lower gear where it will rev high-- it just wont upshift. Any cyclist knows this, even when exhausted I can rev a low gear to near maximum cadence, but try it in a higher gear and I will come to a stop very quickly. When the trans in a auto sees that happening it will downshift to a lower gear or not upshift to begin with, same as when you are going up a steep hill and can't hold it. So it won't shift till near redline (like in passing gear), and it would struggle even then. Then you take your foot off the pedal and it sucks fuel back into the filter because of the vacuum built up from pulling the fuel so hard against the filter, air, etc. So the motor starves and complains and the driveline fights to keep the motor turning while it tries to die on you, lugging you along till the motor gets more fuel again and it runs smoother. In this scenario, I don't see how a limp mode is needed reproduce the behavior ... not to say that it not happening, but I doubt it.