CTIS and Arduino

[SausageGuy]

Put this on my truck tonight and it works awesome. Never thought I would get such a kick out of tires inflating. My truck did not come with a controller so all the valves have not functioned in who knows how long. Each cycle of fill and deflate the pressures from wheel to wheel manually verified got closer to each other till they matched. EXCEPT one wheel that has held pressure for 6 weeks with no CTIS hooked up. Now it never goes up in pressure just down a little each time. Is it a stuck wheel valve?

 

[Ronmar]

Leaking axle seal, fitting or hose? Front or rear? On rear check the axle air vent line where it connects to a vent up on the frame. On the front, roll the wheel so the filler plug on the gear cover points up and remove it and activate the system. You are looking for air coming from that gear oil fill port or the air vent. No air there, get some bubble mix, put it in a spray bottle and start hosing down lines and fittings to the effected wheel valve while it is trying to fill... my guess is it is leaking badly and Less air pressure is reaching the tire than is in it so it opens the wheel valve and drains the tire.

If you have shop air applied to the emer gladhand at the front(chock wheels as it releases the park brake) you might be able to hear a leak if the engine isnt running. Thats how I found my first leak as I couldnt hear it over the engine

The OEM system detects fill anomalies when it checks pressure by doing several checks looking for changing pressure as air escapes thru the leak. This causes the system to fault....

 

[SausageGuy]

Interesting because it is my intermediate axle and I checked differential fluid yesterday and when cracked filler plug it vented pressure. I followed vent line all the way to back of truck where it T's into vent line from other rear axle and then goes to vent. I had not gotten back to trying to see if line is clogged.

 

[patracy]

Here's the ino file.

View attachment ctis_0.8.ino

 

[coachgeo]

Interesting because it is my intermediate axle and I checked differential fluid yesterday and when cracked filler plug it vented pressure. I followed vent line all the way to back of truck where it T's into vent line from other rear axle and then goes to vent. I had not gotten back to trying to see if line is clogged.

Something not dealt with in here yet is something being afoul with the air solenoid mounted on the intermediate axle that activates the locker sitting between the two axles. Conceivably this might could pressurize middle axle if an issue exist

 

[Plasa]

Hello all.
As promised the Arduino sketch for the CTIS controller. The sketch is complete, but the I/O pin's are set on default. This because depends on the wiring (I made a PCB). The sketch is also able to read / write the default pressures of the 4 terrain modes. You need to write the 4 pressure values in the EEPROM memory the first time. Otherwise you get a error warning in the display and the ECU do not work.

Of course the sketch does not cover all the funcitonality of the original one. I have only a M1078, so no functionality for 6x6 or interaxle lockers. But maybe someone will make it better. For me (and now for 5 others) the ECU is working well...

Thanks and regards from Italy!

Christian

Here's the ino file.

View attachment 768588

 

[ramdough]

Hello all.
As promised the Arduino sketch for the CTIS controller. The sketch is complete, but the I/O pin's are set on default. This because depends on the wiring (I made a PCB). The sketch is also able to read / write the default pressures of the 4 terrain modes. You need to write the 4 pressure values in the EEPROM memory the first time. Otherwise you get a error warning in the display and the ECU do not work.

Of course the sketch does not cover all the funcitonality of the original one. I have only a M1078, so no functionality for 6x6 or interaxle lockers. But maybe someone will make it better. For me (and now for 5 others) the ECU is working well...

Thanks and regards from Italy!

Christian

Awesome!

Is the schematic or artwork for your Pcb available too? It would save me some effort if you could post the parts list at schematic. The artwork would be gravy.

Thanks!


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[Reworked LMTV]

I used a 150 psi transducer to trick the system to air my tires up to 80 psi in hgy setting. Since many people would want to run higher pressures I think you should consider changing the transducer as well plus then you would know what to map it to in the sketch.
Tom

Do you have a part # for the 150 psi transducer? Thanks!

 

[m-35tom]

that auction site, it should be obvious by the listing.

 

[Third From Texas]

Do you have a part # for the 150 psi transducer? Thanks!

It's listed below the video.

 

[charlesrg]

Hello all.
As promised the Arduino sketch for the CTIS controller. The sketch is complete, but the I/O pin's are set on default. This because depends on the wiring (I made a PCB). The sketch is also able to read / write the default pressures of the 4 terrain modes. You need to write the 4 pressure values in the EEPROM memory the first time. Otherwise you get a error warning in the display and the ECU do not work.

Of course the sketch does not cover all the funcitonality of the original one. I have only a M1078, so no functionality for 6x6 or interaxle lockers. But maybe someone will make it better. For me (and now for 5 others) the ECU is working well...

Thanks and regards from Italy!

Christian

Christian
Thank you very much for sharing your work. I looked at your code and schematics and seems that there is no Individual tire control, a single relay to release air and one single sensor. So no option of running different pressure in front/rear. I was looking to use the system to help leveling the truck.
Am I missing something or you also could not control front/rear pressure ?

 

[Plasa]

Christian
Thank you very much for sharing your work. I looked at your code and schematics and seems that there is no Individual tire control, a single relay to release air and one single sensor. So no option of running different pressure in front/rear. I was looking to use the system to help leveling the truck.
Am I missing something or you also could not control front/rear pressure ?

Hello!
Thank you Sir.
The problem is that the hole sistem is not single tire controlled, but there's only 1 pressure sensor under the dash. So if you want to control every single tire you need to rebuild all the system. In that chase I would think about using the hydraulik pistons on front axle and see if they can be used for levelling.
Plus inflating 2 or 3 tires take time and a lot of air, to safe air dryer duration I would prefer the hydraulic option...

Christian

 

[jtcawrse]

I thought about this as well.

Really, for leveling using tire pressure, it would be letting air out of individual tires, not actually filling them up.

My thought was to arrive at a campsite, park as level as possible, then use some kind of level system that would tell me how many inches I need to lower at each corner.

Like this: https://logicbluetech.com/product/levelmate-pro-2nd-generation/

Then I could walk around with a tire deflator and let air out as necessary.

Obviously it would be much cooler and convenient to do this automatically but it sounds like that is a complete rebuild of the CTIS.


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[Reworked LMTV]

Hello Ronmar.
No, I don't use the wet tank switch for inflation time. Only for starting the system. Here are the steps:

- open control valve
- after 3 seconds: open inflate valve
- after 3 seconds: close inflate valve
- after 30 seconds: check pressure
- if too low: inflate:
-- open inflate valve
-- after 30 seconds: close inflate valve
-- after 5 seconds: check pressure, if too low, continue inflate, otherwise:
-- close all valves
-- after 30 seconds: open control, after 3 seconds inflate valve, after 3 seconds close inflate valve wait 30 seconds, read pressure
- if too high: deflate
-- open deflate valve
-- after 15 seconds close deflate valve
-- after 2 seconds open inflate valve, after 2 seconds close inflate valve, wait 10 seconds, read pressure. then same as inflate...

The idea for air leaks is good, I will include something to check pressure for 5 seconds, if changes there is a leak. Maybe on every initial pressure check...

Thank you Ronmar!

Christian

Hey Plasa, can you do a video of your set up? Thanks!

 

[charlesrg]

I thought about this as well.

Really, for leveling using tire pressure, it would be letting air out of individual tires, not actually filling them up.

My thought was to arrive at a campsite, park as level as possible, then use some kind of level system that would tell me how many inches I need to lower at each corner.

Like this: https://logicbluetech.com/product/levelmate-pro-2nd-generation/

Then I could walk around with a tire deflator and let air out as necessary.

Obviously it would be much cooler and convenient to do this automatically but it sounds like that is a complete rebuild of the CTIS.


Sent from my iPhone using Tapatalk

I suspect if you air out one tire the pressure may equalize through the system. As they are all interconnected. Hope that's not the case, but it might be.

 

[jtcawrse]

I suspect if you air out one tire the pressure may equalize through the system. As they are all interconnected. Hope that's not the case, but it might be.

I would assume it would only equalize if the truck was running.


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[ramdough]

Christian
Thank you very much for sharing your work. I looked at your code and schematics and seems that there is no Individual tire control, a single relay to release air and one single sensor. So no option of running different pressure in front/rear. I was looking to use the system to help leveling the truck.
Am I missing something or you also could not control front/rear pressure ?

Using tire pressure to level is a bad idea IMHO. For one, you are talking about some inches of difference from a full tire and one that is at a safe (not damaging tire) level. Second, your suspension will take some of that and average your results a little. Third, you are talking about modifying a system that is already know for being buggy. And finally, you could more easily carry some wood blocks and save the cost and headache.


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[Plasa]

Hi there!
I will make one the next time I'm using it. But please don't expect anything magic, it's quite simple and easy...

Hey Plasa, can you do a video of your set up? Thanks!

 

[Reworked LMTV]

Hi there!
I will make one the next time I'm using it. But please don't expect anything magic, it's quite simple and easy...

Hi there!
I will make one the next time I'm using it. But please don't expect anything magic, it's quite simple and easy...

Awesome! Thank you.

 

[Billydeuce]

Hello!
I now build in total 4 and sold 3. If someone need a complete ECU as descibed before I will sell them for 200$ + shipment.

Christian

Are you still selling these Christian?