Community Forums

OneRVer · 09-14-2010, 08:26 PM

My cruise Control will shut off when ever my exhaust brake engages. When my exhaust brake engages my brake lights come on so I figure that triggers the cruise control and turns it off.

Soooo, when ever I am going down a small grade and the fuel peddle backs off just a little the exhaust brake engages and I have to reset the cruise.

Is this common or is there something else I can do to prevent this? Other then turning off the exhaust brake.

DriVer · 09-14-2010, 08:42 PM

Quote:

Originally Posted by OneRVer

Is this common or is there something else I can do to prevent this? Other then turning off the exhaust brake.

In my opinion, an exhaust brake is not needed when you are cruising so turn it off.

If you are going to be off cruise, then I'd tun the EB back on.

OneRVer · 09-14-2010, 10:47 PM

Yep that is what I do now, drive with the exhaust brake off. I would just like to the best of both worlds. I guess it called being lazy.

I was thinking that maybe there might be a wire that I could disconnect between the brakes light and the exhaust brake without messing up the brakes light or cruise.

DriVer, are you the one that was looking for the glass headlights. If so did you find any?

RV Wizard · 09-15-2010, 01:49 AM

Also, be sure not to use cruise control or exhaust brake in slippery road conditions.

FLYING BUTCH · 09-15-2010, 05:52 AM

yep mine does same thing when I first got it I drove 9 hours with bad knee killing me becasue I couldn't use cruise didn't know it would't work with brake on

read & learn · 09-15-2010, 06:04 AM

Why would you use the exhaust brake on a small grade? I have been always told that the EB should only be used on mid to steep grades.

DriVer · 09-15-2010, 06:44 AM

Quote:

Originally Posted by OneRVer

DriVer, are you the one that was looking for the glass headlights. If so did you find any?

Not me sir. I have a lexan/polycarb head light lens most likely from a Chevy Impala on my Winny.

DriVer · 09-15-2010, 06:48 AM

Quote:

Originally Posted by read & learn

Why would you use the exhaust brake on a small grade? I have been always told that the EB should only be used on mid to steep grades.

Many drivers will use the exhaust brake on straight and level roads. When you lift from the throttle the EB will help slow the vehicle and this is a good thing by staying off the brakes. Using the EB is for much more than just grades. In addition to the EB kicking in, select shifting will also play a significant role when properly employed.

Rich and Cork · 09-15-2010, 07:46 AM

I pretty much never turn off my EB. I just hit resume when I want to go back into cruise control mode.

JoeT · 09-15-2010, 08:00 AM

My CAT C7 doesn't do that. My C7 ECM is programmed so that when I go down a hill and my cruise is active and I exceed 5 mph over the cruise set speed, the exhaust brake will come on, but my cruise doesn't cancel. When my speed drops the cruise automatically resumes.
This is a programmable feature in the C7. I don't know it the 3126 is programmable or not. You might call the CAT Help Line to see.

RickO · 09-15-2010, 08:47 AM

I started out having my engine brake on at all times but soon found that I didn't like driving that way. I like coasting at times and I think the ECM has to be reprogrammed to allow that to happen.

I do use it to take the load off of service brakes on level ground at times. Boy, I sure wish Freightliner would have put the engine brake switch on the steering wheel instead of making me reach for it on the dash.

fkloster · 09-15-2010, 09:06 AM

Fascinating! here is how my 1991 ecm works (cat 3176)... when EB is turned 'on' & cruise control is 'on' and the coach starts down down a hill and speeds beyond set speed.... EB never kicks in. But if I switch 'off' cc, then EB will kick in if my foot is off throttle &/or foot is on brake. If I brake with cc 'on' & eb 'on'.... eb kicks in but cc resets. moral of my story? My EB will not kick on when CC is set unless I manually brake. If CC is turned 'off' and I step off throttle, EB will kick in.

OneRVer · 09-15-2010, 11:33 AM

This is how my ECM is set up for the Cruise and Exhaust Brake;

1. Low CC speed set limit. -- 30 mph
2. High CC speed set limit. -- 127 mph
3. Exhaust Brake Mode. -- Manual
4. SoftCruise Control. -- No

I need to know if the Manual on number 3 has an Auto function and what that details.

SoftCruise Control is set for Yes if driving in hilly country. Has something to do with lag or lead time.

Anyway these are the only setting's that I have for EB and CC

JoeT · 09-15-2010, 12:16 PM

The ECM Can be programmed in one of three modes:

Coast Mode - engages the exhaust brake when the brake pedal is pressed and disengages when the pedal is released.

Latch Mode - engages the exhaust brake when the brake pedal is pressed. The exhaust brake will remain engaged when the brake pedal is released until the throttle is pressed or the engine RPM drops below 800 RPM or until the exhaust brake is turned off.

Manual Mode - exhaust brake will activate anytime the exhaust brake switch is on and RPM is above 800 RPM and the engine is not being fueled.

Coast and Latch are available when the Cruise Control Switch is "on". Manual mode does not require the Cruise Control Switch to be "on".