3,000 RPM limit

[Pueblo Dave]

We've got an '05 Itasca Sunrise 31' on a Workhorse chassis. Recently returning from Salina KS to Pueblo CO, we stopped at a light within sight of our house. When it turned green, the rig would barely move, and sounded like it had a good sized bird in the intake. Over about five minutes it slowly cleared up and we could get across the intersection and pull over. As it improved, we got around a corner and into a parking lot. At this point, it would finally rev up cleanly, but would go no higher than 3,000 RPM. Then over maybe ten minutes of idleing and reving it would go higher, until finally it was completely cleared out, and we drove on home, as normal as when we bought it new. The outdoor temp had been hovering around 100 for the whole trip, and the engine temp was completely normal, middle of the gauge. No funny smells, nothing at all unusual. Perfectly fine since. Talked to another Workhorse owner at the state ralley this weekend who had had the same situation and never determined what had happened. We're headed to Bonneville in a couple of weeks and would prefer knowing all is well. Any ideas out there?
Thanks, Pueblo Dave

[Pueblo Dave]

We've got an '05 Itasca Sunrise 31' on a Workhorse chassis. Recently returning from Salina KS to Pueblo CO, we stopped at a light within sight of our house. When it turned green, the rig would barely move, and sounded like it had a good sized bird in the intake. Over about five minutes it slowly cleared up and we could get across the intersection and pull over. As it improved, we got around a corner and into a parking lot. At this point, it would finally rev up cleanly, but would go no higher than 3,000 RPM. Then over maybe ten minutes of idleing and reving it would go higher, until finally it was completely cleared out, and we drove on home, as normal as when we bought it new. The outdoor temp had been hovering around 100 for the whole trip, and the engine temp was completely normal, middle of the gauge. No funny smells, nothing at all unusual. Perfectly fine since. Talked to another Workhorse owner at the state ralley this weekend who had had the same situation and never determined what had happened. We're headed to Bonneville in a couple of weeks and would prefer knowing all is well. Any ideas out there?
Thanks, Pueblo Dave

[oemtech]

There is a built in rev limiter of 3000 rpm when in Park or Neutral.

Also, if you review the forums you will find a number of threads that speak to this subject. No firm answers of WHY it happens or if trans has been damaged. If it happens again you might try disconnecting the battery as this should reset the computer. I would also get a OBD 2 scanner to see if any codes have been set. You may have go to a GM/Allison shop to have diags run as I don't think the OBD 2 scanner will show tranny codes.

[Pueblo Dave]

Dale,I had a hunch this would be the response. Got lots of hits but just your answer, as in nobody knows. I'm not aware of the rev limiter in N or P but the trans was in gear when this happened. So, what do you mean by "try interconnecting the battery"? Maybe you meant "disconnecting" it?
Thanks, Pueblo Dave

[oemtech]

Dang.... the brain is faster than the fingers and auto spell check bites me again.

I corrected the previous post.

[tech@brazelsrv]

I don't suppose you happened to notice on the digital read-out the message 'reduced power'?, you probably would have mentioned it if you had. I've seen this problem a couple of times and has to do with the transmission going into 'protection mode', this usually happens under a rather heavy load in OD. What happens is that it will default to 3rd gear, which in a heavy rig like yours will be totally gutless. Typically, to reset you have to shut the vehicle off for a few minutes and restart. This will reset the transmission to normal operation. As for the fix, basically the transmission is doing what its supposed to. I may be totally wrong concerning your particular issue, this is just something I have seen that kind of resembles what you described.