2009 Freightliner Cascadia ..Intermittent throttle ..(engine light .throttle drops out)

TPS
Throttle position sensor.

 

Your truck is non-def/DPF only if I'm correct. Any other codes on dash? AND does it usually happen when you are going up hill?

 

It's called a Accelerator Pedal Position Sensor, it's mounted to your Accelerator Pedal, or it could be the Pedal itself.

The Pedal can get worn out or have some play in it, which affects the Sensor itself.

When the Sensor or the Accelerator Pedal starts going bad your Cruise Control and Jake Brakes will also function intermittently.

 

Yeah, contact cleaner may help if an important connection has oil in it or what not. Also, it wouldn't hurt to check the grounds real good, especially the one from the starter to the frame ground. You could Clean those up real good with some electrical cleaner spray and also make sure to look over the batteries as well. Checking for corrosion and lose nuts

 

The beginning signs of failure start out intermittently.

Your truck is equipped with Drive By Wire technology.

When the symptoms you describe happen again, check and see if your Jake Brake and Cruise Control work, as they are all tied together.

If the engine sounds like it's turning off, it could also be loose battery cable, starter wire, bad ground.

I would check your Codes to see what Code was Active, but it is now Inactive to try to narrow it down.

 

K, we had a very similar issue that started weeks after an oil change at "SPEEDCO" but it would loose power intermitently going uphill and engine lights would kick on. The solution was very simple yet difficult to diagnose and it took us couple of weeks and 2-3 mechanic opinions that costed us $200+ and down time to pin point the issue.

OUR SOLUTION:
The last mechanic "who barely spoke a word of English" almost immediately pin pointed the problem. Air mixing in Diesel... Basically the truck was running when he noticed small bubbles being formed in the Diesel filter. He drained the filter poped opened the cover and showed us how the rubber seal wasn't even on! Installed new rubber seal problem solved. I HOPE YOUR ISSUE IS AS SIMPLE AS OURS.