Limp mode at the same time during the commute

drharv · **Posted:** Wed Feb 07, 2007 1:28 pm

On my drive home there is a terrible intersection which makes you accelerate from a stop to 80 km/h in a hurry or you will wait for ever. The CRD pulls like a train and skeedattles up to 80 km/h in plenty of time to fit in "the gap"between cars. If I continue with hard acceleration (WOT) I will hit limp mode. I can only assume it is an overboost situation (I also have a 2004 VW TDI and troll the forums which aslo has posts with overboost issues) yet it never hucks a CEL. I throw it in neutral and cycle the ignition, and poof full power again. I know it has little to do with the location and all to do with the driving situation/style. Another tidbit is that it is a right hand turn followed very shortly by WOT. It is a slightly annoying issue but does not dampen my like for the HEEP.

BTW, will the ECU retain a code even if a CEL light is not triggered (I have used VAG-COM on the VW and never found a code that did not have an associated CEL)

Thanks guys/gals,

Mike

BLake · **Posted:** Wed Feb 07, 2007 2:38 pm

Sounds like fuel starvation. Have you checked your fuel filter for air?

http://www.lostjeeps.com/forum/phpBB3/vie ... t=air+fuel
http://www.lostjeeps.com/forum/phpBB3/vie ... t=air+fuel

drharv · **Posted:** Wed Feb 07, 2007 3:31 pm

Thanks for the reply, and I had checked for air in the fuel (none there). This symptom is not lik a shudder or a stumble or anything like fuel starvation type scenario. The beastie goes from going like a bat outta h-e-double hockey sticks, to driving like a normally aspirated old style slow diesel. Cycling the ignition instantly resets the boost and voila! Like new again. On VW TDI this may indicate a clogged EGR (what other symptoms does an egr failure exhibit?) and it will consistent. This situation has happened three times only under acceleration to redline (as WOT will do in an auto) without backing off the throttle. Does anyone think it may have tripped the rev limiter? In any other vehicle I have had the rev limiter just cuts fuel/ignition until the revs drop. Confused.

Oh and I just cleaned my completely clogged boost pressure sensor 2 weeks ago. Went limp yesterday after the cleaning

BLake · **Posted:** Wed Feb 07, 2007 4:45 pm

There are some codes that do not set a CEL. I don't know if a code reader can get them. The dealer can get them for sure.

The EGR on the CRD will set a code if you look at it funny but from what I have read, it doesn't go into limp mode when the valve goes bad.

Any chance you are hitting a slippery patch and setting off the traction control?

drharv · **Posted:** Wed Feb 07, 2007 5:33 pm

I will have the dealer pull the codes, if there are any. Nope, not traction control either. It is the wierdest thing, the Jeep idles, runs smoothly, no misses, it is just out of boost until the ecu is reset with the restart. Very odd. I will try to make it occur regularily befor I get the "seems to work fine for us" line from the dealer.

MACKJ · **Posted:** Wed Feb 07, 2007 7:20 pm

drharv wrote:

...Oh and I just cleaned my completely clogged boost pressure sensor 2 weeks ago. Went limp yesterday after the cleaning...

A little out of left field here, and you may think this is dumb, but have you checked whether you have the plug on the boost sensor upside down... the release clip on the plug should be to the top. I think you can do it and may be the problem?!

Joe Romas · **Posted:** Wed Feb 07, 2007 8:02 pm

OK two things that may be in far left field. (1) on the 06 models they routed the engine harness on top of the engine in such a way as it rubbs on a unprotected part of the fuel filter and it can get chaffed. When you turn right sharply I would think the engine would push the harness into the filter bracket. (2) have you checked your transmission fluid? Again a hard right could be causing all the fluid to go to one side of the pan and suck air.

Goglio704 · **Posted:** Wed Feb 07, 2007 9:45 pm

Could also be caused by the floor mat partially depressing the brake, or a defective/maladjusted brake switch. The ECM will dramatically cut power if the brake and throttle are active at the same time.

Marlon_JBT · **Posted:** Wed Feb 07, 2007 11:27 pm

Those are the exact same conditions that put me into "limp mode". It doesn't happen ALL the time, but it HAS happened before. I expect another occurrence next month. :lol:

naturist · **Posted:** Thu Feb 08, 2007 10:36 am

actually, sounds like a marginally clogged fuel filter to me. I had a very similar problem with a marginal filter, and when the filter clogs, it doesn't shake or cough, it just drops immediately into limp mode.

The first time I experienced something like this, it turned out the dealer's tech had forgotten to tighten a fuel line fitting after working on the CRD, so it was sucking air under full throttle. Very easily fixed, no shake, just immediate limp mode. (and mighty darn limp, let me tell you.)

The second time around, and much later, thousands of mile later, swapping the fuel filter cured it completely. Again, it would accelerate fine up to about 3/4 throttle, then suddenly go into a severe limp. No shake, no shimmy, just instant limp.

BVCRD · **Posted:** Thu Feb 08, 2007 11:03 am

MACKJ wrote:

drharv wrote:

...Oh and I just cleaned my completely clogged boost pressure sensor 2 weeks ago. Went limp yesterday after the cleaning...

A little out of left field here, and you may think this is dumb, but have you checked whether you have the plug on the boost sensor upside down... the release clip on the plug should be to the top. I think you can do it and may be the problem?!

There's really only one way for it to go back together if you are paying any kind of attention at all. You are correct in that the snap clip goes on top. To me it sounds like fuel like natural said.

drharv · **Posted:** Thu Feb 08, 2007 6:17 pm

Thanks for the replies people, I reread my post nad realized I was unclear on the timing of the limps and the bps cleaning....I had a couple of incidents prior to cleaning and another about 2 weeks after the cleaning. I will replace the Fuel filtre (27 000 km and I think it is original) and let you know if that solves the issue.

In reply to the Goglio704, very interestiong. I did not know that the CRD will limp if the brake and accelerator are pressed at the same time. Might have happened...I was wearing boots at the time. I think I will intentionally try that scenario and see what happens. Can this "feature" be deactivated? I can see it being a problem whislt wheeling or backing a trailer uphill into a tight spot.

As I said before, it really doesn't bother me too much, it is just odd.

NHCRD · **Joined:** Thu Feb 08, 2007 10:46 pm **Posts:** 4

My CRD was going into limp mode quite often, so off to the dealer it went. I just have my CRD back now, it was there 7 days....but they were great at fixing it once the parts made it from some place out west. They first tried to bleed the air, no dice, still bogging. Then replced the fuel pressure selenoid, nope not that either. My paper says contacted "star hot line" Is this like the bat phone? anyway Chrysler said to replace the fuel quantity solenoid, Possible injector pump, replaced fuel quantity valve, test drive OK No return codes. Hope this helps....Good Luck

Jeger · **Posted:** Fri Feb 09, 2007 9:51 am

I wonder how many of those two feet drivers out there have sent their liberty into limp mode. You know the ones that you cant tell when they are gonna stop because their brake light is on constantly. I think this brake riding causing a fault code, is triggered by distance traveled while braking and accelerating or something like that....I have never had it go into limp mode by just riding a the brake backing a trailer or taking up slack in a line.

Goglio704 · **Posted:** Fri Feb 09, 2007 11:24 am

Jeger wrote:

I wonder how many of those two feet drivers out there have sent their liberty into limp mode. You know the ones that you cant tell when they are gonna stop because their brake light is on constantly. I think this brake riding causing a fault code, is triggered by distance traveled while braking and accelerating or something like that....I have never had it go into limp mode by just riding a the brake backing a trailer or taking up slack in a line.

I thought it might be tied to MPH. It doesn't seem to come into play when power braking.

drharv · **Posted:** Mon Feb 12, 2007 12:19 pm

I took the advise of one of the respodants, and changed my fuel filter this weekend. A bit of a pain if you have big hands, and the factory gorilla put it on too tight, but other than a little fuel spill it was not too bad. I think it was related a fuel "shortage"under WOT, because I could not get it to limp mode no matter what I tried. So, thanks to the members for their suggestions and fixing problem.BTW, when changing the filter I filled the new one with Power Service, spun it on and the wee diesel fired right up.

BVCRD · **Posted:** Mon Feb 12, 2007 12:25 pm

drharv wrote:

I took the advise of one of the respodants, and changed my fuel filter this weekend. A bit of a pain if you have big hands, and the factory gorilla put it on too tight, but other than a little fuel spill it was not too bad. I think it was related a fuel "shortage"under WOT, because I could not get it to limp mode no matter what I tried. So, thanks to the members for their suggestions and fixing problem.BTW, when changing the filter I filled the new one with Power Service, spun it on and the wee diesel fired right up. No need to prime or bleed air.

You still might want to try to bleed some air out. I got mine started and then shut it off just to see and there was indeed more air in there. "THEY" suggest, that if you pre-fill the filter, to block off the center hole so that no garbage goes down this because it is the out hole and any trash could plug up the injectors. One item that I missed was the small black gasket on the white drain that came on the new filter. I was told that it needed to be used in place of the old one. I failed to see this and used the old one. No leaks though.

Limp mode at the same time during the commute

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