Community Forums

rmilewsk · 07-28-2014, 08:10 PM

The Exhaust brake on our new Tiffin Phaeton 40QBH stopped working on our first major trip. We were returning to Michigan from Glacier Park MT when the Exhaust brake stopped working. It was on a Sunday, but I was able to get through to Freightliner and the Tech was great.

He had me temporarily remove some fuses and it reset and started working. He said it would probably never happen again, but that if it did we needed to get it into a Freightliner dealer. It has happened about Five more times. And it is erratic. Seems to happen when using the speed control. The Freightliner dealer said they cannot do anything unless it is not functioning when we bring it in. From what the Tech said and what I have read it sounds like a computer issue, perhaps the ECM or TCM or both.

Has anyone else experienced similar issues?

garykk · 07-29-2014, 06:39 AM

Over on the tiffinrvnetwork there is a pretty big discussion about it, you're not alone.......surprised no one has made a complaint to the NTSA about it, it is a safety issue and if enough folks complained, Freightliner might actually do something about it

luvlabs · 07-29-2014, 08:11 AM

The exhaust brake does not work when the cruise control is on so you need to drop it out of cruise when using it. Try that, I think you will find it works as advertised.

Stepping on the brake should disengage the cruise but the brake pedal has to return to the full up position for everything to work. Stick your toe under the pedal and pull up. This last part is purely a Freightliner issue but may be caused by people trying to rearrange the cables from the adjustable pedals.

I suggest you go over to the tiffinrvnetwork.com for a better explanation.

rmilewsk · 07-30-2014, 06:36 AM

Quote:

Originally Posted by garykk

Over on the tiffinrvnetwork there is a pretty big discussion about it, you're not alone.......surprised no one has made a complaint to the NTSA about it, it is a safety issue and if enough folks complained, Freightliner might actually do something about it

I'll check it out. I took it to the local Freightliner dealer and he was NO help. Told me that unless it wasn't working he couldn't help diagnose anything. I asked if there was any bulletins or information from Freightliner and he said no, but never really checked.

I agree with your comment about the safety concern. We were were just leaving Glacier Park in MT when we lost it for the first time. I was glad that we chose a route that had minimal grade issues.

rmilewsk · 07-30-2014, 06:53 AM

Quote:

Originally Posted by luvlabs

The exhaust brake does not work when the cruise control is on so you need to drop it out of cruise when using it. Try that, I think you will find it works as advertised.

Stepping on the brake should disengage the cruise but the brake pedal has to return to the full up position for everything to work. Stick your toe under the pedal and pull up. This last part is purely a Freightliner issue but may be caused by people trying to rearrange the cables from the adjustable pedals.

I suggest you go over to the tiffinrvnetwork.com for a better explanation.

Roger, By the way. The Exhaust Brake DOES work with the cruise control on. I have read about this and it functions differently with different coaches. So I have been experimenting to try and solve my issue. When the Cruise is turned on and the coach speed increases approximately 4mph above the set speed, (going down a hill) the exhaust brake engages to slow the coach down.

luvlabs · 07-30-2014, 08:58 AM

The Freightliner exhaust brake function is designed to work with the cruise control off and the throttle position at zero. You must apply the brake to initiate the exhaust brake.

What you described is exactly how my Ford chassis operated. However, the Freightliner is different.

(I think I was wrong about the brake pedal sticking in my first answer - that was another issue. The throttle pedal may not come all the way up, it needs to be a zero for the exhaust brake to engage, and can be lifted with your foot. Freightliner can and should replace the throttle pedal assembly.)

Here's the article on TRVN concerning exhaust brakes: A Part of the TiffinRVNetwork If you are not a member you will need to register to see the article.

rmilewsk · 07-30-2014, 11:57 AM

Quote:

Originally Posted by luvlabs

The Freightliner exhaust brake function is designed to work with the cruise control off and the throttle position at zero. You must apply the brake to initiate the exhaust brake.

What you described is exactly how my Ford chassis operated. However, the Freightliner is different.

(I think I was wrong about the brake pedal sticking in my first answer - that was another issue. The throttle pedal may not come all the way up, it needs to be a zero for the exhaust brake to engage, and can be lifted with your foot. Freightliner can and should replace the throttle pedal assembly.)

Here's the article on TRVN concerning exhaust brakes: A Part of the TiffinRVNetwork If you are not a member you will need to register to see the article.

My EB clearly functions without touching the brake. As soon as I take my foot off the throttle it begins to work and a Greene indicator light on the dash comes on confirming that it is working. From other posts, I understand that Freightliner can change the programming of and EB from throttle to brake.

I just joined the Tiffinrvnetwork. It is very helpful. Many posts on this topic. It appears that a number of 2014 Phaeton QBH owners are experiencing the same EB issues. Some claim that lifting the brake or throttle pedal with your toe will fix the issue.

Thanks for the article!

jjensen04 · 07-30-2014, 05:56 PM

Just had my 2014 Phaeton in to Freightliner for 6000 mile checkup and the EB issue that you are having. They found a brake valve sticking. They said this would effect the cruise control but it should not effect the EB.....They replaced the valve. All I know if I didn't use the cruise control the EB worked fine. I drove to Vegas from Phoenix and the EB worked ok. We shall see but I don't think Freightliner knows what is causing the EB problem yet....

DeWat · 08-05-2014, 10:16 AM

My exhaust brake will not function when my cruise control is on either. However, I have never had any problems using the exhaust brake when not on cruise control, leading me to believe that it is normal programming in my case.

garykk · 08-05-2014, 11:22 AM

I just did a search at NHTSA and no complaints have been filed about the exhaust brake on the Phaetons...

rmilewsk · 08-05-2014, 01:05 PM

We have a 2014 Phaeton 40 ft QBH. We were on our first big trip to Mt. Rushmore and Glacier Park, MT. Upon leaving Glacier Park to return to Michigan our Exhaust Brake stopped working. It was a Sunday and I was able to get through to a very helpful technician at Freightliner. He directed me to turn the EB off and to turn the coach off and to remove SIX fuses from the fuse panel. The panel is located below the Driver's window. It is the first basement door in front on the driver's side. The fuse panel is on the top left wall of the compartment. When you remove the fuse panel cover the Freightliner name is on the inside of the cover, along with a fuse diagram. The fuses that he had me remove are: the top, left 4. They are: IGN SW 30A, IP BATT 5A, CHAS IGN 30A and BODY IGN (OPT) 30A. Also, two fuses which are just right of the number 24 below the Freightliner name on the Frieghtliner fuse diagram in the cover. They are: IP IGN 10A and DASH IGN 10A.

REMOVING AND REPLACING THE FUSES LISTED ABOVE RESET THE EXHAUST BRAKE, and it began working fine. He said that this was probably a one time issue and that it would never happen again, but that if it did, I should take the MH into Freightliner Unfortunately, it has happened, at least 5 times. I have been to two Freightliner dealers and they have told me that unless it is not working when I bring it in they cannot help me. The problem is intermittent. It does seem to happen when I am using the cruise control. The EB does work with my cruise control and works well when it is functioning. The cruise control also malfunctions when the EB is out.

I learned from the Freightliner technician that you can test the EB by getting the MH up to about 35 mph, turning on the switch and taking your foot off the accelerator. A GREEN LIGHT will illuminate on your dash panel and you can feel the brake engage. Your brake lights will also go on, but that can be tough to see, unless it is dark out.

I have read in forums that a number of 2014 Tiffin Phaeton Owners are experiencing similar issues. Some have said that lifting the accelerator or brake peddle with gentle pressure from your toe/foot will fix the issue. I suppose that this may be a mechanical issue with the pedal. This system works in conjunction with the Engine control module (ECM) and the transmission control module (TCM). Being that I and others have noticed that it occurs when using the Speed Control, and because removing fuses resets the system, it would seem more likely that it is a computer/chip/programming issue.

Still attempting to figure out what is going on. Unfortunately, people frequently find out about this issue when they are in the hills/mountains and need their EB. My advice til we get a resolution is to pull the fuses to reset the EB and the don't use the cruise control until you are in flat land.

Bob & Nancy M
2014 Tiffin Phaeton QBH
2014 GMC Acadia Toad with Patriot Brake

jjensen04 · 08-06-2014, 07:50 AM

I have found out by not using the cruise control, I never have a problem with the EB......I had it into freightliner, but they just replace a sticky break pedal value....It should affect the EB.... All I know if I stop and restart the MH it resets and the EB works fine.....

rmilewsk · 08-06-2014, 09:35 AM

I spoke to Tiffin and they directed me to Freightliner (FL). FL told me that the EB in the 14 Phaeton works in conjunction with the gas pedal and SHOULD NOT BE USED WITH THE CRUISE CONTROL. (Some of you tried to tell me this :-).

Therefore, I am going to give this a try. This also leads me to conclude that the posts which have said that lifting the brake pedal with your foot will fix an EB that is not working could fix it are probably not accurate for this model. BUT, it could make sense to lift the gas pedal. Both the EB and Speed Control work off the gas pedal and therefore, I am guessing that my EB problem may be due to conflicts in the software between the two systems.

I hope that this is the end of this issue for us. Thanks for all of your input. Very educational.

Bob & Nancy M.
2014 Tiffin Phaeton 40QBH
2014 Acadia AWD toad with Blue Ox & Patriot Brake

rmilewsk · 08-12-2014, 06:53 PM

Quote:

Originally Posted by luvlabs

The exhaust brake does not work when the cruise control is on so you need to drop it out of cruise when using it. Try that, I think you will find it works as advertised.

Stepping on the brake should disengage the cruise but the brake pedal has to return to the full up position for everything to work. Stick your toe under the pedal and pull up. This last part is purely a Freightliner issue but may be caused by people trying to rearrange the cables from the adjustable pedals.

I suggest you go over to the tiffinrvnetwork.com for a better explanation.

Roger, You were right! Everything is working now!