Need Assistance on my CTIS 923A2

I have check each wheel valve out,have no tire leaks,changed bad axle air seal and still system still does two air checks.First hisses inside cab and then blow off under truck this is done twice. All lights still flash. Any help will be greatly appreciated.

You should get a pressure check on startup when the air tanks reach 120psi. If the system starts filling and you go below 120psi in your air tanks the system will stop filling till it sees the 120psi again. Does the in cab hiss sound like air flowing or is air leaking into the cab from the system? Did you check all the lines and when putting wheel valves back together or connecting lines did you use new o rings? You must hunt down the air leaks it's leaking somewhere.

I'll second that, it's leaking somewhere. 5 flashing is generally a leak and it can't get pressure from somewhere to somewhere else. Generally, it's usually a substantial leak...not a pin-hole. Mine does this when I lose a connection at the wheel hub (slips off).

5 solid lights is much worse.

Rear wheel valves slip up and off all the time. The fronts leak where the line comes out of the hub going to the valve. I double up on the o rings there.

I'll get back on it today after work. Many Thanks.............

Make sure your air is over 120psi. Then start her up. Do you have one blinking light?

If you get the trumpet after that and 5 flashing. ...you have a leak.

You mentioned that you have hissing inside the cab. Is it a contained "hiss" or does it sound like an air escaping near you "hiss".

It should sound like the former.

120psi. Then I started her up. Have quick pssst and then trumpet sound after that all 5 lights are flashing. Changed out O-ring to double O-rings on both front hub pipes that protrudes out 3/8'' or so to no avail. Had to stop because darkness set in. Thanks.........

1. How long is the 1 light (HWY) flashing before the trumpet sound?
The trumpet sound is the system saying "I'm done trying" and blowing off the pressure in the lines in the center of the truck (rubber duck bill looking things). It's giving up.

2. Have you checked to see if there's a valve core in one of the wheels?
There should be no valve core in the short side of the "T" fitting that bolts to the wheel. The longer side (facing out in the front) should have a core in it. If there's one in the short side, you can't fill or exhaust your tires and the system can't check pressure.


Another thought is to check to see what tires are low on air. If you have two on the same axle that are a grossly different pressure than the other 2 axles...I'd start there.

Check the lines that go between the quick release valves and the hubs they dry rot

1. About 2 seconds.

2.It had valve cores in all the stems. I removed the ones from the long side that the hose screws to and installed a new O-ring in the hose end. The short side of the valve stem that faces inward still has the valve core.

What are you referring to as the ''T'' fitting?

I'll check this today. Thanks.....

T fitting is what bolts to the wheel. There should be a valve core in one side and the fill hose attaches to the other.

2 seconds sounds like a valve core is still in there (or something is disconnected in the cab)

After three months of studying, checking, changing out two hubs of air seals that came loose and much help from you men. I finally got the CTIS working yesterday after reading a post by those military guys rob. It's hard to believe that one little tiny wire would prevent the CTIS from working. The cable female end that plugs into the Pressure Transducer that mounts on top of the Pneumatic Controller has three small wires Pink, Black and Blue the Pink was broken loose from terminal. If you have this same problem, remember the silver terminals come out forward from the connector. Also you must carefully remove the strain relief. I could not find these terminals anywhere, so I drilled out the broken wire from the terminal and reused it. Thanks Again, Art

harleyboy1 said:

After three months of studying, checking, changing out two hubs of air seals that came loose and much help from you men. I finally got the CTIS working yesterday after reading a post by those military guys rob. It's hard to believe that one little tiny wire would prevent the CTIS from working. The cable female end that plugs into the Pressure Transducer that mounts on top of the Pneumatic Controller has three small wires Pink, Black and Blue the Pink was broken loose from terminal. If you have this same problem, remember the silver terminals come out forward from the connector. Also you must carefully remove the strain relief. I could not find these terminals anywhere, so I drilled out the broken wire from the terminal and reused it. Thanks Again, Art

Click to expand...

Art, Got your message and read your post. I'm glad you've resolved the issue. One 20ga little wire causing all that trouble... I hope this helps others get their systems in working order.

harleyboy1 said:

After three months of studying, checking, changing out two hubs of air seals that came loose and much help from you men. I finally got the CTIS working yesterday after reading a post by those military guys rob. It's hard to believe that one little tiny wire would prevent the CTIS from working. The cable female end that plugs into the Pressure Transducer that mounts on top of the Pneumatic Controller has three small wires Pink, Black and Blue the Pink was broken loose from terminal. If you have this same problem, remember the silver terminals come out forward from the connector. Also you must carefully remove the strain relief. I could not find these terminals anywhere, so I drilled out the broken wire from the terminal and reused it. Thanks Again, Art

Click to expand...

So just picked mine up and its missing the Pressure Transducer that appears to tie into the fuel system near the fuel primer on the A2 (just above). Is this the same one you are talking about?
If so, do you know it's purpose?