CTIS problems

[walt1985]

It was working fine. We had a slow leak in one tire and we would crank it up and it would air it up fine. Now all five lights are flashing and it won't air up or bag tires down. Any suggestions?

 

[Gunzy]

Try to unplug the controller and reset the system.

 

[atomoros]

I have the exact same problem. When I picked it up one tire was low. It aired up fine and stayed that way all the way home. But the 5 lights are flashing. TM shows this problem and from what I understand it might fix itself by doing just what GUNZY said. It's been too cold for me to start it up yet to try. If you do this, please post up if it fixed the problem.

 

[Suprman]

If there is water/moisture in the system and air lines and it's that cold something may just be frozen up. Wait till a warm day and try it then. Air the truck up and drain the tanks a few times and replace the air dryer desiccant canister.

 

[1 Patriot-of-many]

Try holding down the run flat button until it activates, sometimes mine starts working after the run flat mode is initiated. Sometimes not, Like Suprman said, seems to be a cold issue.

 

[walt1985]

We've unplugged it a couple times. It makes it stop flashing then you hit air up and it waits then you hear it start to inflate one time them they all start flashing again

 

[MtnSnow]

Hope this helps as it explains the different troubles when different number of lights are flashing on the CTIS
View attachment CTIS Troubleshooting_pages_10-11.pdf

 

[walt1985]

Where is the air dryer desiccant canister?

 

[1 Patriot-of-many]

Where is the air dryer desiccant canister?

On top of the air dryer. [smart ass reply off]

 

[MtnSnow]

Where is the air dryer desiccant canister?

Location is shown in the -10 TM on page 122 also known as page 003-48

PM info for Dryer Page 598 of the -10 TM also noted as 0112-18 You can download the TM's right here at this site and I highly suggest doing so!

 

[walt1985]

Can you send me the link

 

[MtnSnow]

http://www.steelsoldiers.com/showthread.php?79228-TM-s-for-the-939-series-trucks

 

[tstates]

After my m923 recovery in Sparta, my ctis stopped working. I had the dreaded 5 flashing lights. Could not understand how it could fail after doing such a good job in such cold weather?? So after searching and taking a full page of trouble shooting notes. I went after it today. Got out the soapy water, shut down rig and started looking for leaks. Found about 6 leaks in line fittings and one wet tank shutoff valve, one in wet tank relief valve, one in a rear tire filler stem fitting. I fixed them all except the valve, need to order one. Then ran out of time. Fired her up to drive it to storage and the ctis started to just flash on HWY. Hey we made progress. Decided to drive down to auto parts store and grab some stuff. Left it running. When I came out, did a walk around to check things out. I heard a hiss on another rear tire (old Michelin) and went closer to inspect; low and behold it was leaking on the sidewall, where it had a big 2" cut. When Jeff and I recovered it, he pointed that area out to me, and noted it was marginal road worthy at best. I'm thinking that it my have given out on the 1043 mile journey, because it was all aired up before I left?? Anyway, hope to fix that and get some parts and be 100% soon. Much thanks to all for the wealth on info on this site.

 

[cumminsbandit]

So you can get the 5 flashing lights just from the smallest leaks? I just don't understand how it knows there are leaks. there are no sensors on the wheels or any of the air valves...? The truck is next to perfect other than this... such a bummer...

 

[Suprman]

The valve body in the cab has air in, air out and a pressure sensor. It sends air to do a pressure check if there is a leak and it senses it, then you get a fault.

 

[mcmullag]

The air dryer is in front of the ....front most rear axle....on the passenger side but still inside of the frame rail. Descant thing looks like a really big oil filter. I paid $167 for that filter and a rebuild kit at a truck shop here. There is a Youtube video about working on this thing.

 

[tstates]

One must remember, these are "magic black boxes" You never know what the heck makes them work or go haywire. I am just glad I found some leaks, pretty good ones, and at least for now CTIS works great. Tomorrow, it may not.??

 

[those military guys rob]

something to look at first is the plug that goes in to the transducer on top of the ctis control valve in the cab, I went through my whole system followed everyone's advise and did what the tm's said when I had 5 flasking lights, I started testing all the wires and found that the wires in that plug had come right out of the connector and it caused the 5 flashing lights once I fixed the wires it worked perfectly, So now I know the transduce is a major player in the 5 flashing lights it could even be a bad transducer not just wires. We have now found 2 trucks with the same problem it is hard to check be cause the use shrink sleeve that has the glue so you need to cut the shrink sleeve off and cut back the wire cover and do a continuity test.
I hope this helps

 

[walt1985]

This may have a common sense answer but is the ctis also the ecu unit or are there different items? We have the technical and operators manual. Is there any other material I could purchase for repairs or just more knowledge?

Walt

 

[harleyboy1]

I had two air seals that came out of there seat and caused my air leak issues. Each wheel hub has two air seals. The best way to check this is, run truck till CTSI does air checks around 120 psi. Then shut truck off, flip leavers on but do not start engine. Have second person climb under truck and get as close as possible to one hub. Have person in cab push highway button and system will do two air checks. You can easily tell if you have a hub seal problem you will here air gushing out of hub. Repeat process to all six wheel hubs. Yes, I had to pull one front wheel down and one rear wheel down. But the repair was worth it.