LLY: Truck wont rev past 2 grand??? WTF???

[Nevadahiroller]

So last night i bought my first Dmax! Its an 05 CC/SB Chevy. I bought it down in the Stockton area and drove it back to Reno. The truck ran great all the way till about 20 miles from my house. THEN.......I was cruising at about 65mph and all of the sudden the check engine light came on. So i let off the the accelerator and double checked all of my gauges. Everything was good, nothing out of the ordinary that i observed. But when i tried to get back into the throttle, it wouldn't rev past 2 thousand RPM. Once it hit 2 grand, it would fall on its face and chug. Almost like a rev limiter of some sort. So i pulled off at the next exit and double checked all the fluids after a few minutes of cooling down and everything was good. After sitting for about 1 minutes, i figured i had to get the truck home regardless and hit the road again. The check angine light was still on but it drove like normal again. I was getting full throttle response and it was not chugging at 2 grand anymore. Weird! Since this truck is my first diesel, and it was almost 1:00am, I figured i would wait till morning to dig a little deeper.

Has anybody ever had this happen with their truck before, or have any ideas of what could be causing this??

I am at a loss right now and it is almost 2:30am. I need sleep!

Thanks for your time and input!

 

[LBZ]

What you experienced was limp mode. When something happens that the truck doesn't like such as too much slippage in the transmission, or a major engine malfunction, it derates the fuel to limit the engine to 2000rpm.

You need to check the codes and see what comes up. This should give you a better idea of what the problem was.

 

[dmaxfireman]

my bet is fuel limp trans limp makes you stick in 3rd i dont think theres and rpm limit on a trans limp. which is good news for you! :thumb:

 

[Cougar281]

my bet is fuel limp trans limp makes you stick in 3rd i dont think theres and rpm limit on a trans limp. which is good news for you! :thumb:

x2. Probably got a P1093 code.

 

[stacks04]

fuel filter.

 

[RENODMAX]

I can help you later this week Cody

 

[fast03]

fuel filter x2

 

[BlkMax]

How many miles on the truck?

When that happened to me, I thought it was the fuel filter and it ended up being fuel pressure regulator on the CP3 pump

Since I had 135k on the CP3 I took the time to upgrade to an II modded CP3, and EFI Live.

I really do hope it is the fuel filter in your case.

 

[McRat]

Yup, sounds like a P1093. Fuel filter can cause it. It can also be the FPRV, fuel pressure relief valve. While not common, even stock LLY's can have FPRV issues, and GM now sells the FPRV solo. If you intend on hotrodding the truck, you will either have to shim the factory valve or swap out with a race valve if you want more than 375rwhp in a LLY.

 

[Nevadahiroller]

Thanks for all of the quick responses!!! You guys are fawking awesome!:hug: The truck has 142,000 miles on it. I hope that it is the fuel filter. That would be a nice fix for me to do. Sounds like Jordan and I will get to the bottom of this.

So what exactly causes the FUEL LIMP MODE to turn on? Obviously Clogged fuel filter but could it have been bad diesel?????

 

[McRat]

Cut open the filter and look. Yes, bad fuel can cause it.

The engine commands a fuel pressure # by asking the CP3 pump to give it more fuel. There is a rail pressure sensor that reads the pressure. If the actual pressure does not match the commanded pressure within a certain value, it throws the P1093 code and goes into 2000rpm limp mode. EFILive tuning can disable the limp mode.

But there is something else going on. If the actual fuel pressure goes too high, the FPRV opens up, and dumps all the pressure in an instant. The computer sees this event as low pressure, not high pressure, and throws the P1093 as well.

So both low pressure, and high pressure can be the villain.

 

[Nevadahiroller]

I see!!!! The fuel filter is gonna get the knife!! :rofl: Thanks for the great info!

 

[Alligator]

Congrats on the purchase, sorry about your issues. Fuel filter is the most common culprit. Let us know if that fixed the issue.

 

[Nevadahiroller]

WELL........Jordan looked at my truck today and it was throwing the P1093 code. So we changed the fuel filter and............NO MORE CODE AND IT RAN GREAT! Thanks Jordan! it is throwing another code that we are not too sure of. That code is B0229. I tried to search it on here and couldn't find a great explanation for the code. We tried clearing it and it immediately comes back every time. Where can I find an explanation of this code and a solution for it? Thanks again for all the help fellas!:thumb:

 

[Kat]

WELL........Jordan looked at my truck today and it was throwing the P1093 code. So we changed the fuel filter and............NO MORE CODE AND IT RAN GREAT! Thanks Jordan! it is throwing another code that we are not too sure of. That code is B0229. I tried to search it on here and couldn't find a great explanation for the code. We tried clearing it and it immediately comes back every time. Where can I find an explanation of this code and a solution for it? Thanks again for all the help fellas!:thumb:

B0229 Recirculate Position Feedback Circuit Range/Performance HVAC Control Module

Not sure why your A/C is throwing a code.

Make sure nothing came unplugged when you changed the fuel filter.

 

[whitetrash21]

WELL........Jordan looked at my truck today and it was throwing the P1093 code. So we changed the fuel filter and............NO MORE CODE AND IT RAN GREAT! Thanks Jordan! it is throwing another code that we are not too sure of. That code is B0229. I tried to search it on here and couldn't find a great explanation for the code. We tried clearing it and it immediately comes back every time. Where can I find an explanation of this code and a solution for it? Thanks again for all the help fellas!:thumb:

Code: B0229
Modules: HVAC Control Module
Description: Recirculate Position Feedback Circuit Range/Performance

Congrats on the new ride.

edit: nvrmind, Kat beat me to it.

 

[LBZ]

If your a/c is working fine and it was me, I would just get hooked up with efi and turn the code off.

 

[Cougar281]

If your a/c is working fine and it was me, I would just get hooked up with efi and turn the code off.

You can't turn the C or B codes off.

 

[Nevadahiroller]

HMMMM. So I guess if its not broke...........don't fix it!:thumb: Thanks for all the replies!

 

[whitetrash21]

HMMMM. So I guess if its not broke...........don't fix it!:thumb: Thanks for all the replies!

My 03 used to have a code similar to that set every time the DTC were pulled. Never had aproblem with it so I forgot about it.

Pretty much what you said, I'd do.