CTIS pressure settings increase - no programming, transducer, or module required.

[billyoffshore]

Gotcha....thanks for the Update !..........We also do want to minimize changes on our M1078A1 Harness too. Quick question: Did you get the Highway pressure up to 80 PSI ? (or changed to what you wanted?) on the M939A2 ? Also, is the "plaza Arduino CTIS Unit on the Forum here ? I was just about to look it up and read about it. Do you like it?
and,
Hey, Hike.......Have a Good Christmas and New Years! Thanks for the info !
BTW, I used: buydeutsch.com (Nice Product Selection and Real Deutsch and good $$ & shipping).

One other thought Hike: As far as "removing / Pulling " those pins on the M939A2, How about a Nice "Male / Female" Deutsch Connector, Three Pin Plug and Socket, on that "G, X, and W wires a on that P110 Harness on our M1078A1's ? I would use the "Gold Pin" units from Deutsch, and it would be "Clean Looking / Not Molested so to speak. It could have the Nice Duetsch Caps on them when Unplugged, and the M939A2 is in place. Then, if in the future a Good DANA Unit was purchased, it can get that harness plugged right back together nice.
Just a thought.
I actually wire up and install systems on Sport Fishing Yachts for a living. I am MUCH more familiar with NEMA 2000 Networks (and have been to the Certification Seminars), then I am with J1939 CAN.

 

[hike]

One other thought Hike: As far as "removing / Pulling " those pins on the M939A2, How about a Nice "Male / Female" Deutsch Connector, Three Pin Plug and Socket, on that "G, X, and W wires a on that P110 Harness on our M1078A1's ? I would use the "Gold Pin" units from Deutsch, and it would be "Clean Looking / Not Molested so to speak. It could have the Nice Duetsch Caps on them when Unplugged, and the M939A2 is in place. Then, if in the future a Good DANA Unit was purchased, it can get that harness plugged right back together nice.
Just a thought.
I actually wire up and install systems on Sport Fishing Yachts for a living. I am MUCH more familiar with NEMA 2000 Networks (and have been to the Certification Seminars), then I am with J1939 CAN.

That sounds nice and likely will look good. In the spirit of this thread would it make sense to create a patch and switch box to take advantage of the different programing? Within the patch box you could reroute the wiring as needed and enable switching the ground and power routes to take advantage of different programming.

I pulled the pins from inside the Deutsch connector on the M939A2 CTIS ECU, leaving M1078A1 P110 Deutsch connector and harness untouched and functional. That made sense in my head as it is the 'foreign' part added to the M1078A1.

I may have to tap your skills as I add accessories. I have been saving all the wiring and connectors we pull out hoping to repurpose them. For example, we are planning to repurpose / relocate the rotating light circuit / wiring out the back to run our off road lights using the Deutsch connection at the cab skin keeping the dash switch and PDP factory.

It is nice to find another similar vehicle. Ours is tagged 04/2003 20337 or is it 18146 in the door jamb? I am never sure which is actually the serial number—

 

[CallMeColt]

I have an MTV and disconnected M wire only. Now goes to 82 psi hwy(using a very cheap pressure gauge).
Problem is, now when I turn off the truck the quick release valves open on the front axle and the rear most axle. My front right tire goes down to 50 psi and my rear right tire goes down to 55. So now I need to figure that out. Front right was just rebuilt with new CTIS seals and valve / o-rings for the hose.

Possible you have an imbalance somewhere. When you have a system running at 80psi, it is much more sensitive to kinks and/or obstructions between the wheel valve (s) and the quick release valves. Any air left because of this will make the system think it was commanded to deflate. I had this issue a LOT when I ran an 80spi HWY setup until I had no imbalances.

 

[aw113sgte]

Possible you have an imbalance somewhere. When you have a system running at 80psi, it is much more sensitive to kinks and/or obstructions between the wheel valve (s) and the quick release valves. Any air left because of this will make the system think it was commanded to deflate. I had this issue a LOT when I ran an 80spi HWY setup until I had no imbalances.

System is working pretty well after rebuilding all wheel valves and associated seals(and a few CTIS hub seals). Still not super happy on deflate - sometimes requires a few pushes of the button due to a relief valve feedback error. Very finiky system that doesn't have well defined specifications for certain operations (I have the Dana diagnostic software)

 

[GeneralDisorder]

System is working pretty well after rebuilding all wheel valves and associated seals(and a few CTIS hub seals). Still not super happy on deflate - sometimes requires a few pushes of the button due to a relief valve feedback error. Very finiky system that doesn't have well defined specifications for certain operations (I have the Dana diagnostic software)

What did you end up doing for that error again? You might want to replace the relief valve or try a whole different PCU since I have never seen that problem with any other truck. My system works flawlessly on my '08 A1R and I've never had to press a mode button more than one time.

 

[aw113sgte]

What did you end up doing for that error again? You might want to replace the relief valve or try a whole different PCU since I have never seen that problem with any other truck. My system works flawlessly on my '08 A1R and I've never had to press a mode button more than one time.

I adjusted the pcu relief valve pressure, worked great for a while. Guessing I have too much contamination of wheel valve filters as it had more issues when temp dropped. Per spec it has a 1 or 2 psi tolerance...seems a bit sensitive. I have new filters coming and the system still works fine as long as I push the mode button a few times. I know ther was some oil in the system and if valves contaminated and temp drops it would reduce flow due to viscosity...just a guess though. I did cut a wire for the higher pressure settings and it may have different tolerance values (so said a Dana engineer) so I'm going to reconnect it per the 6x6 wiring schematic.

 

[GeneralDisorder]

I adjusted the pcu relief valve pressure, worked great for a while. Guessing I have too much contamination of wheel valve filters as it had more issues when temp dropped. Per spec it has a 1 or 2 psi tolerance...seems a bit sensitive. I have new filters coming and the system still works fine as long as I push the mode button a few times. I know ther was some oil in the system and if valves contaminated and temp drops it would reduce flow due to viscosity...just a guess though. I did cut a wire for the higher pressure settings and it may have different tolerance values (so said a Dana engineer) so I'm going to reconnect it per the 6x6 wiring schematic.

If you haven't rebuilt or replaced all the wheel valves that could easily be the problem. They are typically NASTY inside.

I would also replace the PCU relief valve and rebuild the PCU if it hasn't been. It requiring adjustment is a great troubleshooting step but ultimately this indicates to me that something is falling out of spec. Better to just get a new one that's known to be within spec.

 

[aw113sgte]

If you haven't rebuilt or replaced all the wheel valves that could easily be the problem. They are typically NASTY inside.

I would also replace the PCU relief valve and rebuild the PCU if it hasn't been. It requiring adjustment is a great troubleshooting step but ultimately this indicates to me that something is falling out of spec. Better to just get a new one that's known to be within spec.

I fully rebuilt the wheel valves except for those filters everything else has been replaced.
Fully rebuilt the PCU as well.
I adjusted the relief valve to get the proper feedback within the Dana software as you can view relief valve pressure.
I haven't looked too much but if I see a new relief valve for a reasonable price I'll get it. Have some new filters coming in one of those yearly maintenance kits.
It works well enough now so it hasn't been a top priority.

 

[CallMeColt]

I fully rebuilt the wheel valves except for those filters everything else has been replaced.
Fully rebuilt the PCU as well.
I adjusted the relief valve to get the proper feedback within the Dana software as you can view relief valve pressure.
I haven't looked too much but if I see a new relief valve for a reasonable price I'll get it. Have some new filters coming in one of those yearly maintenance kits.
It works well enough now so it hasn't been a top priority.

I have rebuilt quite a few of the wheel valve assemblies. The filters, even when they look okay, tend to restrict air flow. Easy way to see if they are the culprit it to remove them all around & give it a try. They generally get destroyed when removed as per design.

The last issue I found on my truck before everything worked perfectly was oil/rtv gobs in the hard line on the hub. That couples with nasty filters & hoses that had kinks that were hard to see.

If you suspect one wheel, isolate it and try the system. For example, plug the line from the quick release valve to a wheel. If that area is the issue, the rest of the system will work fine. Of course if you have multiple issues, you will chase multiple. Then, you can isolate one leg at a time. That was how I figured the passage of air was restricted in the hard line of the hub.

Once it works, it works great. Mine has not had one hickup since.

 

[Ronmar]

Filters are between the wheel valve and the tire. They would not effect valve operation, only the tires overall ability to transfer air.

a wheel valve not closing after a cycle is probably due to A restriction on the truck side of the wheel valve. Basically the truck side cannot vent cleanly down to a pressure low enough to allow the wheel valve diaphragm to seal the center hole and cut off its air source From the tire. the tire is able to supply the air as fast as it is being released and keep the truck side pressure on the diaphragm high enough to hold it open and continue to drain. Usually the tire will bleed down to a point where it can no longer supply the air as fast as it is being released and the diaphragm pressure finally drops low enough to allow the spring to close it…

that is all the relief on the PCU does. It acts as a restriction on venting the PCU to atmospheric pressure, holding it at~6-7 PSI(regulator). This drops the pressure on the truck side down just high enough to keep the wheel valves open for maximum pressure difference and the fastest dump possible. You could put a 20PSI relief in there and it should work the same only lower pressure difference and slower tire dump rate.

at the end of a cycle the control solenoid opens and vents the system to 0PSI. The dump valves see this on their input port and immediately command a full dump of air on their output/wheel side To copy that 0PSI on their input side. This full dump quickly lowers the pressure at the wheel valves which, seeing less than minimum opening pressure, quickly slam the diaphragm shut on that center port. This should result in a brief(1/2 second) honk from the dump valve ports as their supply is quickly cut off At the wheel.

if your dump valves persist in dumping after control is open, wheel or dump valves are not responding cleanly/performing to spec, or you have a restriction somewhere maintaining system pressure above the wheel valve cutoff pressure…

 

[Gunny 0369]

,

 

[aw113sgte]

Filters are between the wheel valve and the tire. They would not effect valve operation, only the tires overall ability to transfer air.

a wheel valve not closing after a cycle is probably due to A restriction on the truck side of the wheel valve. Basically the truck side cannot vent cleanly down to a pressure low enough to allow the wheel valve diaphragm to seal the center hole and cut off its air source From the tire. the tire is able to supply the air as fast as it is being released and keep the truck side pressure on the diaphragm high enough to hold it open and continue to drain. Usually the tire will bleed down to a point where it can no longer supply the air as fast as it is being released and the diaphragm pressure finally drops low enough to allow the spring to close it…

that is all the relief on the PCU does. It acts as a restriction on venting the PCU to atmospheric pressure, holding it at~6-7 PSI(regulator). This drops the pressure on the truck side down just high enough to keep the wheel valves open for maximum pressure difference and the fastest dump possible. You could put a 20PSI relief in there and it should work the same only lower pressure difference and slower tire dump rate.

at the end of a cycle the control solenoid opens and vents the system to 0PSI. The dump valves see this on their input port and immediately command a full dump of air on their output/wheel side To copy that 0PSI on their input side. This full dump quickly lowers the pressure at the wheel valves which, seeing less than minimum opening pressure, quickly slam the diaphragm shut on that center port. This should result in a brief(1/2 second) honk from the dump valve ports as their supply is quickly cut off At the wheel.

if your dump valves persist in dumping after control is open, wheel or dump valves are not responding cleanly/performing to spec, or you have a restriction somewhere maintaining system pressure above the wheel valve cutoff pressure…

20 psi (or anything a couple psi off expected) will cause the controller to error out after 30 seconds of dumping and show to solid lights between the target and higher pressure selections.

 

[Ronmar]

Yep, because the controller is not seeing what it expects to see, ~6-7 PSI. But the plumbing portion won’t care, and would cheerfully deflate the tires to that 20PSI relief valve setting

So what pressure are you seeing during deflate, and how are you measuring that pressure?

 

[aw113sgte]

Yep, because the controller is not seeing what it expects to see, ~6-7 PSI. But the plumbing portion won’t care, and would cheerfully deflate the tires to that 20PSI relief valve setting

So what pressure are you seeing during deflate, and how are you measuring that pressure?

It was at 5.5 and I was getting the error, I increased it to 7-8 and the error went away for a while. This is in the dana diagnostic software. Also verified the pressure sensor is reading correctly with a mechanical gauge. It got colder and the issue popped up again...guessing oil in the filters.

 

[Ronmar]

Is the pressure still 7-8? How did you increase the pressure? The air that the relief regulates during a dump is fed back from the dump valves

under manual control when you open the deflate solenoid, PCU pressure drops to that relief pressure and the dumps exhaust Trying to get the tires to that pressure. If you close the deflate solenoid, the PCU pressure will steadily increase due to that feedback air from the dump valves. As this happens the dump valves will progressively decrease their venting as the tire side and PCU side pressures equalize.

what I am getting at is there are 2 parts to the dump pressure equation. Relief valve and dump valve feedback that provides the air that the relief is venting/regulating to a specified/measured pressure…

 

[aw113sgte]

Is the pressure still 7-8? How did you increase the pressure? The air that the relief regulates during a dump is fed back from the dump valves

under manual control when you open the deflate solenoid, PCU pressure drops to that relief pressure and the dumps exhaust Trying to get the tires to that pressure. If you close the deflate solenoid, the PCU pressure will steadily increase due to that feedback air from the dump valves. As this happens the dump valves will progressively decrease their venting as the tire side and PCU side pressures equalize.

what I am getting at is there are 2 parts to the dump pressure equation. Relief valve and dump valve feedback that provides the air that the relief is venting/regulating to a specified/measured pressure…

Haven't checked pressure, been working on more critical things (system still works, just have to push the specific button a couple times - it errors out after 30s of deflate time).
The relief valve has a spring and there is a little winged nut thread locked in place. A little heat allows the nut to be spun to adjust the relief pressure.

 

[GeneralDisorder]

Haven't checked pressure, been working on more critical things (system still works, just have to push the specific button a couple times - it errors out after 30s of deflate time).
The relief valve has a spring and there is a little winged nut thread locked in place. A little heat allows the nut to be spun to adjust the relief pressure.

They can go out of spec and also get debris in the seat, etc. The relief valve on my air dryer got some rusty crap in it and started leaking and I found out through some research that Haldex had increased the pressure of the relief valve on these dryers so I changed it out to the new spec. I was able to disassemble the original, clean it, and reassemble to keep in my on-board box of air fittings.