While traveling at highway speeds the engine stopped working / stalled. shifting to neutral and trying to start the vehicle was not successful. the vehicle without the assistance of power steering or power brakes had to be carefully stopped . this was extremely dangerous! after looking at an on-line forum, the vehicle with the 8.1 liter engin had some vehicles recalled with a cam lobe sensor fault which causes this to happen. after contacting the dealer, they told me that my vehicle was not in this recall. however, when the vehicle was new, they had already replace the same part when the vehicle was 3-5 months old. i questioned them as to the replacement part as the first part only caused the check engine light, not completely disabling the engine. it may be they replace the factory original part with a part which was defective and covered by the recall. in eather case, a engine on heavy duty vehicle which quits and disables the normal brakes and steering is extremely dangerous.