No Exhaust Brake - No other symptoms

[Craig A.]

Hope someone can give some insight. Here it goes…..

Problem - No exhaust brake engagement

Conditions - Exhaust Brake button depressed, Exhaust brake light illuminated on the dash

Brand new City Diesel Turbo Actuator, I can hear it self test on key cycle, when I replaced the actuator the actuator arm moved freely from stop to stop with no resistance

H&S Mini Maxx is indicating TC Locked when I’m expecting to feel the brake kick in but I get nothing. As the truck slows it downshifts like it normally would with the EB engaged but I get no braking horsepower. It’s as if the ECU is just not sending a signal to the actuator to engage

Few other notes - conditions here in the Northeast are favorable for Exhaust Brake during idle to warmup, nothing, no engagement. This happened a few weeks ago and I didn’t think anything of it. Next time out, worked fine, now I consistently have nothing. Tow/Haul mode engagement has no effect other than changing the shift points as expected

Any thoughts ?

 

[Topzide]

Do you have boost as they go hand in hand? If no boost, then there is something else going on. If you have boost then the wiring from switch to turbo control needs to be checked. You'll need to check tuning as your running a DELETED truck.

 

[Craig A.]

Do you have boost as they go hand in hand? If no boost, then there is something else going on. If you have boost then the wiring from switch to turbo control needs to be checked. You'll need to check tuning as your running a DELETED truck.

No boost on deceleration which tells me the vanes arnt moving. But no other drive ability issues. Truck makes power without issue.

Truck has been deleted for 8 years with no issues prior to this occurrence. Always drive with the EB on and have never had an issue. No changes have been made that would warrant an issue.

 

[TMyers]

Has the EB worked since the actuator was changed? My first thought was the actuator isn't operating at full range or a calibration issue. (I know City's don't require calibration.)

 

[Craig A.]

Has the EB worked since the actuator was changed? My first thought was the actuator isn't operating at full range or a calibration issue. (I know City's don't require calibration.)

No EB prior to or since the actuator change. The EB not working is what prompted me to change the actuator from what I read

 

[Diesel85]

Two questions:

When you replaced the actuator, how did the vane lever feel when you were moving it back and forth? Was it easy to move? Any notchy feeling? Or did it feel gummy?

The actuator will try to calibrate and if the vanes are notchy, gummy or hard to move, it won't calibrate correctly. Your turbo needs to be replaced.

Also, what is your battery voltage upon start up?

The City Diesel Actuator re-calibrates each time the truck is cycled. (Unlike the OEM.)

Below 11.0v the City Diesel Actuator won't finish it's calibration correctly.

If the battery voltage drops too low (below 11.0 Volts) it may not make a full trip and the very extreme ends of travel will not be used. This makes the exhaust brake weaker but does not cause a check engine light or limp mode.

 

[Topzide]

How many hours total on the truck? The factory units last about 4K hours. how many miles? No codes being thrown? Mine started throwing codes that could be cleared but returned in a few days to then being the next start up. @Diesel85 brings up a great point, what's battery voltage and age of the batteries? Low voltage in these trucks causes gremlins! I would be looking for a melted and or disconnected wiring harness that goes to the turbo first, then maybe it'll be time to tear down again to check the vanes for how they feel. I know that every time I go to start the truck, I hear the vanes go through self check. Are you sure this is taking place? Asking these questions to get a better feel on what is taking place to try and find the answers that you seek.

 

[cricha]

There is a glitch in the programming of the City Diesel actuator that doesnt allow the EB to function normally. There is info on it in the TDR quarterly magazine in the article evaluating the CD actuator. It has since been updated to a slightly different starting sequence that allows the use of the EB. I tried it, (I have a CD actuator) and the EB works on my truck when following the cold start sequence, but the EB doesnt seem as robust.

 

[BigPapa]

There is a glitch in the programming of the City Diesel actuator that doesnt allow the EB to function normally. There is info on it in the TDR quarterly magazine in the article evaluating the CD actuator. It has since been updated to a slightly different starting sequence that allows the use of the EB. I tried it, (I have a CD actuator) and the EB works on my truck when following the cold start sequence, but the EB doesnt seem as robust.

If you're referring to the "STILL PLAYS WITH TRUCKS" article in issue 122 by James Langan, page 79, I just spoke with Jackie, owner of City Diesel (we buy a lot of Actuators), and he said that there is NOT a "glitch in the programming" of their Actuator, that there is no programming in the Actuator to have a glitch in. The Actuator is an electronic part that is controlled entirely by the ECM. Mr. Langan had a low voltage issue, 10 volts. Jackie said if the voltage is low, the actuator won't fully self-calibrate as it should when the key is turned on.

 

[cricha]

Yes, that was the article. Appreciate the correction Scott. Thanks for posting your conversation with City Diesel.