Community Forums

Dougjpr · 05-08-2018, 10:55 AM

Will a malfunctioning output speed sensor always through a code?
If so, will code be in transmission computer or vehicle computer?
Getting rough shifts, no codes from trans keypad, fluid level 'ok' according to keypad

Skip426 · 05-08-2018, 11:04 AM

Bad trans sensors , should put a code into the trans controller , and show up with the pad access .
Questions ?
Is this a new problem , on a coach you've had for a while?
Or a problem on a new to you coach?
Any record of trans servicing ; fluid and filter change ?
Do you notice any issues with engine power ?
Because of the way the trans shift program interacts with input from the engine controller , particularly the TPS ( Throttle Position Sensor ) , any performance issues with the engine will result in shifting problems .
Engine fuel filters changed recently ?

Dougjpr · 05-08-2018, 11:18 AM

Thanks for reply
2005 Dutchstar ISL 370, 3000MH trans
48,000 miles
We purchased from dealer last spring
All fluids and filters changed before we took delivery, including trans fluid and both filters.
Fuel and oil filters just changed 1000 miles ago.
Problem just noticed the other day. Very harsh shift from 5-4, 4-3 harsh but not as bad, 3-2 about same as 4-3. this was with exhaust brake on. With exhaust brake off, downshifts are harsh but not as bad.
Up shifts seen fine except a slight pause on 3-4 causing the rpm's to come up a bit.

The shifting issues have never been noticed before. Once in a while a harsh downshift with exhaust brake on, but not always. I thought that may of just been a product of the speed and other things going on at the time.

Not sure if this is related or not, but I did notice a break in the exhaust pipe just before it enters the muffler. Not sure if engine monitors back pressure or not, and if this could have any relation to shifting. Have never noticed a break at this point before and coach just had a safety inspection at beginning of April, so would of hoped any break would of been noticed.

Did a 1000 mile run a couple of weeks ago, no issues.

Thanks

Skip426 · 05-08-2018, 11:30 AM

Any exhaust leak past the engines turbo , will not effect performance .
Exhaust manifold flange gaskets and cracked exhaust manifolds are common and without a boost gauge can be hard to detect.
Is the shifting an issue in both trans shift pattern modes ; power & economy ?

Power mode , in my coach, provides a much rougher shift .

Dougjpr · 05-08-2018, 11:35 AM

That is kind of what I thought about the exhaust, but wasn’t sure if the reduction in back pressure would cause any issues, not 100% certain on everything the computers are monitoring.

Have only ever run the coach in ‘normal’ mode, and this just started.

Luckily it was on way to storage yard and we are not in middle of a trip.

Got some time to get it checked out