Ford Engine

[ajkishgolf12]

My Sunstar 29 engine light came on my current trip. We are in the mountains and towing a small car. It appears that on every hill large or small the engine downshifts to 3000 rpms and then 4000 rpms. This does not happen when the cruise control is on. This has been happening with or without a car. Not familiar with downshifting.

Wondering if anyone had a similar issue. Have a appointment with Ford when I return next week.

[SarahW]

Are you using the tow-haul function? We do not use cruise control when driving in the mountains; it's easier to control RPMs when not.

[ajkishgolf12]

When I first used that feature I noticed the higher RPM downhill when I used that function. I didn't like the way it felt so I tried not using it. For awhile I did not have the problem with the high rpm. It almost appears to be stuck in that function. It's annoying every time I take my foot off the gas it revs up going down hill.

I only been using the cruise control do it doesn't rev to 4000 rmp when I am going 65 and start to go down a small him. I would prefer just to glide and tap the break.

Any thoughts on the cause or is this normal?

[Jim_HiTek]

My '02 Class A pusher, Freightliner chassis with 6-speed Allison seemed a bit weird on it's selection of downshift points when in the hills or mountains so whether on CC or manual, I just tap the shift buttons when I feel it's the best downshift point. That's usually at 46MPH going uphill, I'll drop it down to 4th. If the hill is fairly long, as the speed drops I'll tap it down to 2nd and leave it there. This accomplishes the thing I want the most, keeping the engine temp below 1/2 of the gage scale.

When the hill flattens, I just tap D. So it's a dynamic thing, and I think it benefits the machine for you to involve yourself in seeing that you're in the best gear for the situation rather than trying to let the CC+tranni+engine computers try to maintain speed. Just too much for the tranni firmware AFA I'm concerned. I don't like the lurching the thing does as it hunts for the best trade offs if I let it do it's thing.

On down hills, again, the tranni firmware is rather weird (though it works better than downshift points on uphills) so I'll just tap the brake to disengage CC when I crest a hill, and let the exhaust brake keep my speed down. The CC does active the exhaust brake when the speed gets 5 MPH above set point, but it's kind of flakey so I'd rather do it myself.

The hills need to be fairly gentle for me to just let CC and the downhill exhaust brake controls by the CC do the job alone.

[powercat_ras]

Often you can self reset the yellow check engine light on Winnebago Class As by operating the Chassis Battery Disconnect Switch by the entry door for a minute or two when you have the RV parked with the ignition key off. This does a hard power cycle on the Engine Control Module.

You can go to an auto parts store like Advanced Auto Parts and they will read the code for free , so you can see why the light came on before you reset it. Or you can buy a Ford OBD2 code reader and do it yourself anywhere.

[thompwil]

Sounds like it's stuck in a Twilight Zone version of Tow-Haul mode.

When using tow haul a tap of the brake pedal going downhill will activate engine braking and may initiate a downshift which will increase rpms in an attempt to maintain current speed. Tapping again may initiate another downshift.

Continued brake application will cause more downshifting and engine braking which is nice if you need to reduce speed, or if you're approaching a red light.

It will coast downhill in tow haul if no brakes are applied but you may need to maintain some throttle. At least that's how ours works.

edited for clarity

[BirchyBoy]

My wife doesn’t like the RPM’s when I use tow/haul downhill but it beats burning the brakes up or going faster than I’m comfortable with.

[ajkishgolf12]

Thanks for all your input. Feel I need to watch my load too. The check engine light is off now. Still will bring it in for service to see if the tow haul feature is still stuck which I feel it is.