I know it's simple, but how do you fix a tranny limp? Just turn truck off? Unplug TCM? Or what?

That didn't work for me when I limped pulling my trailer. I think it has to be off for a certain amount of time. I don't know how long. My truck didn't return to normal until the next day.

I'd like to know, too.

"low fuel rail pressure" code and the truck didn't go over 2,000 RMP.

Dealer blamed it on my Napa Gold fuel filter. If it was really the case I've had problems with 2 filters. That said I have one on now and it's doing just fine. I cut the last filter open to check if I was getting bad fuel and it looked new. The 2 "problem filters" had 2,000 miles and 310 miles on them.

I believe that you just pull over turn the truck off and it's done.
Did you limp it on the 85hp tune? :)

Well he has the predator, i wonder if he could just clear the code, restart and go....?

How in the heck did you limp your truck bone stock????? (MoEngineer)

Oh wow, im shocked. Im glad you got it fixed though!

Thanks, but I'm not calling this one fixed. After changing several filters the truck stopped giving me the code. I think the pressure sensor may be the cause not the filter. The dealer refused to test it, the tech denied that the sensor existed.

I haven’t pulled the trailer in several months, if I will shortly. If it happens again I’m switching filter brands to OEM and sending it back to the dealer. If it doesn’t, I’m golden.

But back to thread topic: If it does happen, how does one “reset” without a scan tool?

Did you limp it on the 85hp tune?

Nope, haven't limped yet. Actually, thanks to Philbilly2's indepth tranny limping research, I've followed his orders to the letter and am currently running a Predator 85 HP/Edge 90 HP stack on a stock tranny without limping so far. I realize that I'm on borrowed time (I've got Mike L. on speed dial:cool: ), but it's worked so far. But there's a DHRA event this weekend, and I'm not goin' all the way over there to lose...so I figure I might be fixin a tranny limp this weekend:eek:.

I know it's simple, but how do you fix a tranny limp? Just turn truck off? Unplug TCM? Or what?

To get the truck out of limp mode when you limp it, just pull over and shut it off. Wait 30 seconds or so and the truck will be out of limp when you restart is. You will notice that the SES light is on still. This is normal. The truck is suppose to go through 3 warm-up /cool-down cycles with the SES light on. If you shoot the code, it will almost always be a P700 code. A predator box will not clear P700 codes(trans codes). I don't know why, but I do know not to worry, the light will go away.

I know it's simple

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if you have an allison 1k lct tranny all you have to do to get limp( if the trans is ok but not the electronics) is pull the main trans connector(bottom right hand side of the trans looking at it from the rear) off.

The predator can clear codes in the ECM but the TCM will continue sending the CEL to the ECM because the predator will not clear codes in the TCM. Strange but thats whats going on. The predator can also check codes from the ECM but not the TCM. Trying to track down a place right now that can clear TCM codes so i can goto the dealer hopefully for some warranty work.

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Now, Now Greg. Just because you own 2 of my Alli's doesn't mean you have to get upitty here. ):h :D

A quadzilla tuner will clear TCM codes...but it wouldn't "Fix a tranny limp";)

Thanks, but I'm not calling this one fixed. After changing several filters the truck stopped giving me the code. I think the pressure sensor may be the cause not the filter. The dealer refused to test it, the tech denied that the sensor existed.

I haven’t pulled the trailer in several months, if I will shortly. If it happens again I’m switching filter brands to OEM and sending it back to the dealer. If it doesn’t, I’m golden.

But back to thread topic: If it does happen, how does one “reset” without a scan tool?


I think your having the same problem I was. Its not a tranny limp but the motor not reving up allowing it to shift out gears. My did this in cold weather and was caused by the MAF sensor being bad. Changed fuel filters said bad fuel yada yada yada... Took a while but turned out to be a sensor.

SnowBandit,
What codes did you get, and what pointed to the MAF? I'm still expecting this to happen next time I hook up the trailer.

Thanks.

Low Fuel Rail Pressure code sounds like a 1093 and is not tranny related. That is an engine limp and it limits the engine rpm to 2000 to try to avoid damage. It may affect the way the tranny shifts based on the RPM limit and associated reduced power output. If I understand this correctly, a tranny limp should give you something like "incorrect 5th gear ratio" (if you limped 5th gear) and downshift to another gear.

I think I was geting the P0087. I still have to paperwork, I'll check it again this weekend.

SnowBandit,
What codes did you get, and what pointed to the MAF? I'm still expecting this to happen next time I hook up the trailer.

Thanks.

Not sure on the codes... But they finally did was start looking at all the harness. The figured it out when they looked at the two temps in the air intake and saw one reporting -40 all the time. What year truck? Early 06's LLY had this problem.. A few other people I have heard have this same problem.

Bad batch of sensors?????

I think I was geting the P0087. I still have to paperwork, I'll check it again this weekend.

A P0087 code = Fuel Rail Pressure To Low

Trans codes are all P0700 codes;whenever I limp my trans it shoots these 3 codes:
P0700 = Trans Control Sys Malfunction
P0704 = Clutch Switch Input Circuit Malfunction
P0781 thru P0784 Shift Malfunction (which one of those you get depends on what gears you are between when it limps

Okay, I have not limped my trany. I have limped the engine. My Mistake

Anyone know how to reset an engine limp without a scan tool. I tried pulling off he road and shuting it down for 5 minutes. It didn' work. Then next morning, it was fine.

When I limped my Tranny/Engine which ever one it was passing heards of turtles on the freeway, 5-4 down shift, all I did was pop er' in neutral for a few to 10 seconds and pop er' back in drive and Censored at every one of the turtles that I had to re-pass...

I have a scan gauge that I use to clear the codes and get power back... You have to figure out whats causing the problem thou. Mine was gelling fuel...