M923 A2 CTIS Diagnosis Help

[TheUziButton]

I have an M923 A2 that will not inflate the tires above 15psi. I have even tried manually inflating the tires to 45psi and within 20 minutes all the tires are deflated back to 15psi. The ECU does not indicate any errors. The only thing that I can detect that is out of the ordinary is a whistling noise originating from the driver’s side wheel well when the PCU cycles through each of the tires but I cannot detect the exact point of origin. Is this a stuck valve? If so, where can I find it? Any help on how to resolve this issue would be greatly appreciated.

 

[MuleMac01]

The whistling noise is most likely a blown CTIS seal inside the hub letting air out you need to fix it before you diagnosis the system,.. happened to my 5 ton on the rear last week I'm fixing it now.

 

[simp5782]

Get your spray bottle of soap and water out and start spraying your wheel area. You may have smaller leaks that you can't hear. Weird that one is making the noise but they all deflate. Wouldn't suspect bad O-rings at that rate but things happen.

 

[Andyrv6av8r]

I have an M923 A2 that will not inflate the tires above 15psi. I have even tried manually inflating the tires to 45psi and within 20 minutes all the tires are deflated back to 15psi. The ECU does not indicate any errors. The only thing that I can detect that is out of the ordinary is a whistling noise originating from the driver’s side wheel well when the PCU cycles through each of the tires but I cannot detect the exact point of origin. Is this a stuck valve? If so, where can I find it? Any help on how to resolve this issue would be greatly appreciated.

Are you TheUziButton from ArfCom?

 

[Andyrv6av8r]

The whistling noise is most likely a blown CTIS seal inside the hub letting air out you need to fix it before you diagnosis the system,.. happened to my 5 ton on the rear last week I'm fixing it now.

This

 

[Suprman]

Usually a bad hub seal sounds like a siren. Windex or soapy water is your friend.cAir leaks when the system is filling trick the mechanical valves into dumping air rather than filling. So you have enough pressure escaping on fill to trick the valves but not enough to fault the computer on initial pressure check.

 

[TheUziButton]

Are you TheUziButton from ArfCom?

Yep! That's me! Its good to see another arfcomer!

 

[Rooster828]

Did you ever figure out your problem. I am having the same issue

 

[TheUziButton]

Did you ever figure out your problem. I am having the same issue

It was a CTIS hub seal issue.