Here I am

Exhaust brake issues

Attention: TDR Forum Junkies
To the point: Click this link and check out the Front Page News story(ies) where we are tracking the introduction of the 2025 Ram HD trucks.

Thanks, TDR Staff

Turbo area screeching squeal

Another DEF Question

EZeis

TDR MEMBER
Hello all,
2018 Ram 3500 SRW aisin transmission 4wd. 102k miles. No codes. All factory stock. No prior issues or codes. Not a single part has be replaced other than general maintenance. I run in tow/haul and full-on exhaust brake all the time since it was new. So, if anything, its worn vs soot built up.

My exhaust brake started having issues on cold startup. It would either not come on or only partly. Only did it when below 20's, intermittently. Now it's doing it in warmer weather. Like today it was 70F and the engine was cold but no exhaust brake warm-up. It came on partly at the first stop about a 1 mile down the road. Also, it is starting to not always coming on right away at speed, like a 5 second or so delay. The truck runs find though sometimes I get a throttle delay. I've monitored boost as high as 32 psi on the dash. I also noticed the truck shows boost while the exhaust is working, but I don't monitor that screen on the dash. But I don't recall it ever showing boost and exhaust braking HP at the same time. Note, once or twice during the one winter I did have the exhaust brake stick on during throttling.

I have been watching the turbo actuator command and position, and it always follows the command, which I assume is the PCM command. So, I assume it's not the actuator as it does follow the command unless it's not reporting correctly. I was thinking it needs the turbo actuator replaced but no codes and the position follows the command. I don't want to drop almost a grand on an actuator if that's not the actual issue.

Another odd thing that started the same time is my engine coolant temp runs higher than it ever has while towing and towing up grades. normally the fan would keep the engine 212F and less. Now I can see coolant temps up to 224F. It's like the fan control is off spec. The fan doesn't seem to come clear up to speed when it should and when it does it runs until the temp drops to the 180's. Not sure if the two are related.

I've been on tech authority trying to buy a factory service manual and it just keeps sending me in loops between tech authority and MoparTSP with no signs of buying a service manual. I haven't kept up on the later trucks, so I was trying to learn what all items the PCM looks at to command the exhaust brake or maybe a trouble tree. Maybe they don't sell them anymore and I need a subscription to access factory service data.


Thanks,
Earl
 
How many combined hours on the truck? At about 4K hours, the actuator will start to fail. Are your boost psi still the same? If they aren't, you need one. This is the same road that mine went down a few years back. If you do need actuator, order a City Diesel unit from Genos Garage. Same price as City Diesel sells them for, and it helps support the TDR site.
 
Engine temp can be related to a partly clogged radiator stack, I had the same two year ago. Taking the stack apart and clean out every radiator by itself cleared the issue.
There was a lot of road debris stuck inside the fins of these radiators.
Since then I'm back to normal.
 
Engine temp can be related to a partly clogged radiator stack, I had the same two year ago. Taking the stack apart and clean out every radiator by itself cleared the issue.
There was a lot of road debris stuck inside the fins of these radiators.
Since then I'm back to normal.

It's on my list to thoroughly clean the coils. I have commercial coil cleaner at work I can use. Thought about a water pump and thermostat too but they seem to be ok. Unless the thermostat isn't opening fully and fine until under towing load. I've had that happen on previous vehicles. As well as stick halfway. Slow to heat up and slow to cool back down.


Thanks,
Earl
 
Are you sure that it’s not normal programming? 70°F is a bit warm to use the EB for warmup. There isn’t much EB use with the switch anyways .

My 18 used far less EB for warmup, with the switch, than the early 6.7’s and the 22 didn’t change a thing with the EB switch. I’m fairly certain Ram was programming it out of operation over the years due to increased soot loading from back pressure on a cold engine. My 05 pushed crazy amounts of soot into the oil when I used the EB for warmup, so much that I quit that practice 15 years ago and never looked back, just drive them to warm them up.
 
How many combined hours on the truck? At about 4K hours, the actuator will start to fail. Are your boost psi still the same? If they aren't, you need one. This is the same road that mine went down a few years back. If you do need actuator, order a City Diesel unit from Genos Garage. Same price as City Diesel sells them for, and it helps support the TDR site.

Total hours on the truck engine is 2647. 101,275 miles. No noticable boost issues. I see up to 32 psi. Which my understanding is that is normal for a stock engine.

That's the plan once I confirm that $985.00 actuator is that I actually need.


Thanks,
Earl
 
Are you sure that it’s not normal programming? 70°F is a bit warm to use the EB for warmup. There isn’t much EB use with the switch anyways .

My 18 used far less EB for warmup, with the switch, than the early 6.7’s and the 22 didn’t change a thing with the EB switch. I’m fairly certain Ram was programming it out of operation over the years due to increased soot loading from back pressure on a cold engine. My 05 pushed crazy amounts of soot into the oil when I used the EB for warmup, so much that I quit that practice 15 years ago and never looked back, just drive them to warm them up.

I've had the truck since new. I know how the exhaust brake is supposed to work. Lol It will heat the engine to a about 160F coolant temp and kick off. So if the coolant temp is under 160F it will come on for warmup. I always use high idle and exhaust brake to heat the engine up to about 80F before I roll. It will come on when you stop until it hits the 160F coolant temp. As soon as I start the engine I turn tow/haul on and exhaust brake on.


Thanks,
Earl
 
If your boost is good then it’s likely not your actuator. How is using the EB when driving?

Do you have anything to monitor VGT position like a CTS2/3? They show where the EB is actually at and that will help diagnose issues (why I know the EB switch didn’t do much for warmup, but it did definitely do something on colder days).
 
As far as the manual, I think that now, all you can get is a subscription. I think that they stopped selling manuals. You can get a short subscription, and print all the pages and put in a binder. I was able to get a digital thumb drive manual and wiring diagram.

The City unit has been great! Seems to ramp up a bit smoother the the stock unit. Biggest thing is to have the area clean and dry upon install. You'll have to drain coolant. So if you need hoses, that would be the time to do it. I replaced mine and added aluminum Y's for bling.

Tell tale signs for the actuator are, lack of boost and low EB. Seems most fail around 4K, but can vary.

Basic Engine stuff should be the same from a 2014 to a 2018. I can find out in my manual if you need.
 
If your boost is good then it’s likely not your actuator. How is using the EB when driving?

Do you have anything to monitor VGT position like a CTS2/3? They show where the EB is actually at and that will help diagnose issues (why I know the EB switch didn’t do much for warmup, but it did definitely do something on colder days).

I agree unless the actuator is only have an issue in the close direction. Trying to find out what all controls the exhaust brake. I know the exhaust pressure sensor plays a roll. It changes so I don't believe it's plugged up unless it's intermittently plugging up. I do plan to pull the sensor and clean the ports and feed line.

Yes yesterday started using my alfaobd monitoring some PIDs. I attached what I'm monitoring. I'm seeing the turbo match the command. Runs from 10% to 100% from what little I've been monitoring and playing with the throttle. What confuses me is exhaust brake comes on about 93% but yet it idles at 93% closed. So why isn't it on at idle too. I don't understand how it can brake at 93% but idle at 93% without braking.

First screenshot is engine off, key on. Second is idle in park. Just some examples. My exhaust pressure sensor doesn't go to zero. I assume that's its lowest range reading.

The exhaust brake during driving seems spot on except I've had a couple times where it came on with a 5 seconds or so delay. Enough to be like wth and you start to panic. That's happened 3 or 4 times. Last time was coming down a 6% grade with the 13k 5th wheel. Exh braked for a turn,came out of turn with foot on throttle and the next turn when I lifted my foot, it didn't come on and then finally did. I also had in the winter where it stayed on after I throttled up and stay on down to stopping instead of the usual 18ish mph. Once stopped it finally went off and the. Came back on for cold engine warmup.


Thanks,
Earl

Screenshot_20250426-184127.png


Screenshot_20250426-184139.png
 
Last edited:
Never forget about the updates through the years, they can change behaviors of the truck significantly.
But also be small and unnoticed.

It's been a few years since I had any software updates. But that wouldn't explain intermittent issues with it in warm-up. Like ranging from not working or partial or long delay. Even had it "stick" on with throttle open.


Thanks,
Earl
 
As far as the manual, I think that now, all you can get is a subscription. I think that they stopped selling manuals. You can get a short subscription, and print all the pages and put in a binder. I was able to get a digital thumb drive manual and wiring diagram.

The City unit has been great! Seems to ramp up a bit smoother the the stock unit. Biggest thing is to have the area clean and dry upon install. You'll have to drain coolant. So if you need hoses, that would be the time to do it. I replaced mine and added aluminum Y's for bling.

Tell tale signs for the actuator are, lack of boost and low EB. Seems most fail around 4K, but can vary.

Basic Engine stuff should be the same from a 2014 to a 2018. I can find out in my manual if you need.

That's what I figured. They just haven't removed the icons for the manuals that just loop you in circles. But when I get a chance I will pay the 3 day subscription and download it. That's how I had to get the manual for my 2014 VW I had. VM has a tech site like that.

Yeah if I need an actuator, it will be through Geno's and be the city brand.

I don't seem to have any boost or power issues.i do occasionally get an unexpected throttle delay when pulling out from a stop. Which could be a low boost off idle condition.


Thanks,
Earl
 
Airflow at idle and 93% is vastly different than 2500 rpms. The closer to idle you get slowing down the closer to 100% the VGT should be in EB mode.

If commanded and actual EB position match its likely not your actuator.

Maybe pull and clean the BP sensor?
 
Airflow at idle and 93% is vastly different than 2500 rpms. The closer to idle you get slowing down the closer to 100% the VGT should be in EB mode.

If commanded and actual EB position match its likely not your actuator.

Maybe pull and clean the BP sensor?

But the exhaust brake at warmup is at idle. That's why I say it's confusing that 93% closed can and can not be braking, including at idle. But I will try to catch it working at warmup to see what it goes to at idle. Maybe 100% vs 93%.

BP sensor? You mean MAP?
 
But the exhaust brake at warmup is at idle. That's why I say it's confusing that 93% closed can and can not be braking, including at idle. But I will try to catch it working at warmup to see what it goes to at idle. Maybe 100% vs 93%.

BP sensor? You mean MAP?

BP = back pressure. Clean that.

93% is plenty for braking at high rpms and plenty for increased backpressure at idle. You only want a few psi of back pressure at idle to get the benefits of warmup without the negatives of too much back pressure.

Going back to my earlier post the truck will not apply full back pressure at idle, it’s not good for a cold motor. Yes it heats up faster, but long term it has a negative effect on the oil.
 
BP = back pressure. Clean that.

93% is plenty for braking at high rpms and plenty for increased backpressure at idle. You only want a few psi of back pressure at idle to get the benefits of warmup without the negatives of too much back pressure.

Going back to my earlier post the truck will not apply full back pressure at idle, it’s not good for a cold motor. Yes it heats up faster, but long term it has a negative effect on the oil.

The exhaust pressure sensor? That's on my list to clean. The sensor, the ports and the connecting tube. It varies in readings. Doesn't go to zero with engine off and key on as I mentioned. But I do know that sensor readout is use by the PCM to control exhaust brake function. I've read they can plug up with soot but they would get a code. I'm not getting any codes. Even the time the brake stayed on during acceleration I didn't get a code. I assume the PCM doesn't monitor those things or there has to be a huge difference.
 
@EZeis, Just wanted to check on something, have you done a CCV replacement and EGR & Cooler clean? The amount of build up from this system may help you to determine what's going on.

On another note, don't rely on the grid heater wiggle test! I upgraded the grid heater power connection with the BD kit. When I was in there, the wiggle test didn't move the connection under manifold plate! Just a heads up on that issue. I created a thread on it. Keep the info coming for others to learn from!
 
@EZeis, Just wanted to check on something, have you done a CCV replacement and EGR & Cooler clean? The amount of build up from this system may help you to determine what's going on.

On another note, don't rely on the grid heater wiggle test! I upgraded the grid heater power connection with the BD kit. When I was in there, the wiggle test didn't move the connection under manifold plate! Just a heads up on that issue. I created a thread on it. Keep the info coming for others to learn from!

Yes I replaced the CCV filter twice now. No, haven't clean the EGR circuit. There is no schedule maintenance on those items on the later trucks.

I saw your post on the grid heater hardware.
 
50's this morning, no warm-up from the exhaust brake. No change in command/position of the turbo actuator with the switch. No change in the exhaust pressure with the switch. No exhaust brake sound. Seems there is something preventing the exhaust brake for warm-up. Unfortunately I don't know what all parameters the PCM looks at for the exhaust brake to troubleshoot. Hopefully when I get a chance to get a subscription on tech authority I can find some valuable information and/or troubleshooting. Whatever it is, it's getting worse as I only had issues when it would get down below 26F. Now it's doing it in often and in warmer temps.
 
Back
Top