Problems with 07 Volvo Cummins ISX engine

It sounds like it has Gear-Down Protection set in ECM, some trucks have it others don't, its an option. I think dealer can turn it off for you. It doesn't make any sense whatsoever, I hated it too. Here is some info about it, still doesn't make any sense to me, but hey what do I know about big fleet drivers World. Not much

Gear-Down Protection.
Gear-Down Protection promotes increased fuel
economy by encouraging the driver to operate
as effectively as possible in top gear, where fuel
consumption is lower. It does so by limiting vehicle
speed one gear down. This only happens when
engine sensors read that the engine is operating
in a “light” load mode. Under light loads, when
downshifting would be unnecessary, Gear-Down
Protection can be set to limit vehicle speed very
noticeably, thereby providing the operator with a
strong incentive to remain in top gear.
When lugging uphill or pulling heavy loads, Gear-Down
Protection allows access to the full operating range of
the engine in all gears. Therefore, under heavy load,
the operator can accelerate up to heavy-load vehicle
speed in any gear. This allows the vehicle to perform
well under heavy loads, but still encourages the use
of the most efficient gear.

 

Just to clarify, does the truck have enough power to work or does it have no power at all?

 

If it didn't do this before and you didn't take it into a shop to get a new calibration in it before this started then it is not gear down protection. Check your fuel filters to see if anything is clogging them. To me is sounds like a fuel delievery issue.

 

I have the exact same problem... same truck.. 07 volvo ISX.. it didnt use to do this...now it will do it even in reverse... lol.. if you figure it out..please let me know.. our shop can not figure it out.. he thought maybe boost sensor ..but it didnt help..

 

http://www.thetruckersreport.com/tr...elers/159161-2007-450hp-isx-eractic-rpms.html