M923A2 CTIS Problem

[phxmark]

Top light flashes on mine while it's building pressure then once the tanks are almost full all lights start flashing. I tried the "disconnect/reconnect" fix and that didn't work so I guess it's now down to checking each component. The truck has less than 500 miles on it since original issue so my guess is something is clogged for sitting 23 year or an o-ring has rotted someplace. At least the tires stay inflated all the time.

Are you getting four or five flashing lights? Four flashing seems to represent a problem with a sticking valve or a leak and five seem to represent an electrical component issue.

If you are getting four flashing, try running the system in run flat mode. I have to put the system on mine in run flat mode when it is cold. It will return to normal mode after 10 minutes and things seem to work normally after that.

Here is a link to the CTIS Troubleshooting Guide:

http://dana.com/wps/wcm/connect/25f3...acfff859534476

 

[cumminsbandit]

So today I was hard up to figure out my 5 flashing light problem... The CTIS worked when i got the truck then just stopped. My front two tires both lose air over time at different rates and was like that when i got the truck. So after i got the 5 flashing lights everyone one here says my system must have a leak and may be causing my problem. I just didnt understand why it worked fine when my tires leak and now it doesnt work and my leaks are still there and have not changed. So this really made me think a leak was not my problem.

My dad has a really nice M931A2 that everything works good on so today i started swapping parts. I took my CTIS control box out and plugged into his truck and it ran his system fine. I put it back in my truck and then took the sensor off the top of my CTIS air valve and put it on his truck and again, everything works good. I put that all back together and then took the whole darn air valve out and put my dad's in my truck and BAM! That was it!... Works great now!

Earlier this winter in an attempt to fix this, i checked all the air pressure sensors and all were good and then had the gut feeling that it was the air valve so i removed it and completely ripped it apart to see what made it tick. All looked good and clean so i recleaned it all and checked all the O-rings and relubed the valves and put it all back together and installed it and it didn't do a darn thing. So i had to walk away from it for awile.

I have looked for hours on this great site and have downloaded the CTIC troubleshooting guide and spent my share of time doing research and i just dont think i would have found the problem if i didn't have parts to swap out. I am happy that the more and more i look into this kind of stuff the smarter i will be in future problems of this kind. Thanks again for all the great info from everybody on here and i hope my findings may be helpful to others.

 

[SLOrazorsedge]

Sounds exactly like the issue with my M932A2 that has frustrated any efforts of diagnosis . What and where is the air valve you are describing? Any chance of a couple of pics?

 

[Hawssie]

I also have a 5 lights a flashing issue which turned out at least at first to be one of the plugs going to PCU that has three wires going to it. The harness was replaced with what must have been a generic one as all the plug leads are way to long compared to original and were zip tied up under the dash, also the 3 wire plug I am talking about was not a plug anymore but three bare terminals that were just stick into the switch end and weren't even put in the right place. Anyone know where to get plug ends? But the screwiest thing is after the hwy light stops blinking and the system is supposedly filled, the system is only at 50 pounds! Now this is a wrecker which according to the newest specs should be at 90 psi. I wonder if the computers are programmed differently for the wrecker compared to the rest of the models that should be at 70 psi.

 

[mkcoen]

Are you getting four or five flashing lights? Four flashing seems to represent a problem with a sticking valve or a leak and five seem to represent an electrical component issue.

If you are getting four flashing, try running the system in run flat mode. I have to put the system on mine in run flat mode when it is cold. It will return to normal mode after 10 minutes and things seem to work normally after that.

Here is a link to the CTIS Troubleshooting Guide:

http://dana.com/wps/wcm/connect/25f3...acfff859534476

Mine flashes just the Highway light until the air builds up then all 5 start flashing.

 

[SLOrazorsedge]

Same here with mine. My truck was a brand new never issued M932A2 with 9 hours on the meter and 90 miles on the odometer. CTIS worked great for a number of months until the cold snap here in Calif. The hiway light activates when the truck is fired up. Truck makes air pressure to normal range, CTIS starts cycling and then bam, 5 flashing lights. I have the exact same symptoms as what "cumminsbandit" had. Now I want to see what air valve he's talking about.

 

[cumminsbandit]

It is the valve that is on the floor on the right hand side of the shift tower down by your feet. It is under the winch control tower if you have winch or has a tin guard over it with 3 small bolts holding it down. There are two electric plugs going to it and two air lines. A black one and a yellow one.

 

[cumminsbandit]

I am guessing these valves just are getting old and once the cold hits it just makes them harder to actuate... I wonder if you can get them new at an Eaton dealer? I think mine has the Eaton part # right on it!?

 

[SLOrazorsedge]

Thanks bandit, I'll be checking on that valve. I wonder if there is a rebuild kit out there?

 

[harleyboy1]

I also have a 5 lights a flashing issue which turned out at least at first to be one of the plugs going to PCU that has three wires going to it. The harness was replaced with what must have been a generic one as all the plug leads are way to long compared to original and were zip tied up under the dash, also the 3 wire plug I am talking about was not a plug anymore but three bare terminals that were just stick into the switch end and weren't even put in the right place. Anyone know where to get plug ends? But the screwiest thing is after the hwy light stops blinking and the system is supposedly filled, the system is only at 50 pounds! Now this is a wrecker which according to the newest specs should be at 90 psi. I wonder if the computers are programmed differently for the wrecker compared to the rest of the models that should be at 70 psi.

This was one thing that was wrong with my CTIS. After replacing two sets of axle wheel air seals (fun job) this was my final problem. One of the three tiny wires was broken off at the top of the metal terminal. What some folks don't realize the terminals plug in backwards into the plastic plug. You have to run the wires through the bottom side up through the plastic plug out the topside about 2'' or so. Then crimp or solder or both like I did, then pull wires from back side of plug to seat terminals. That's why the harness has a (looks like a strain relief) 3'' or so rubber end that you can roll back or remove as I did to service the broken terminal. If it were me, I would purchase a used one or two foot harness with end and make a solder splice. Hope this helps !!!

 

[MA1911]

I manually set all tires to 46 psi. I turned on the truck an selected hwy, it flashes for a minute then the air valve open and it starts dumping all the air out. I only have 1 flashing light and it is what ever mode I select. Has anyone had this issue? I drove the truck home from auction the hwy light was solid red the whole ride home. Once I hit my dirt road I selected xc and it's had this issue ever since

 

[atomoros]

This CTIS is driving me nuts......

 

[Over]

If the system is attempting to fill but the front tires are deflating then you have a fill air leak. The system is sending fill pressure but due to a air leak the front wheel valves are only seeing around 12psi which holds the wheel valves open and makes you dump air. Probably a bad hub seal somewhere.

My CTIS just flashes whatever light its on. When I hit the emergency after awhile it went solid but when I press HW it just flashes(one light) and doesn't air up. I can't drive on the emergency air pressure 12 lbs. Also on the front pass wheel a loud whistling sound is coming from the back of the wheel when on HW setting. Is that my seals leaking?

 

[Suprman]

If it sounds like a groaning siren it's a bad hub seal. A bad hub seal can truck the wheel valves into thinking they are seeing dump pressure and your tires will deflate. If you think there is a leak around one of the wheel valves find an assistant with some windex and spray the valve lines and stuff.

 

[Over]

If it sounds like a groaning siren it's a bad hub seal. A bad hub seal can truck the wheel valves into thinking they are seeing dump pressure and your tires will deflate. If you think there is a leak around one of the wheel valves find an assistant with some windex and spray the valve lines and stuff.

Kind of a high whistle. No leak on the outside CTIS gear. Will go outside and spray around that seal. It's the big rubber boot looking one around the ball joint? Just the Highway light blinking.

 

[Suprman]

Does the system do an initial pressure check and then attempt to fill air? You will hear air moving thru the cab valve body in spurts usually.

 

[Over]

Does the system do an initial pressure check and then attempt to fill air? You will hear air moving thru the cab valve body in spurts usually.

Yeah just went out there to check. No leaks around the axle where the hub meets. It runs thru the checks then the pass wheel whistle starts. Whats weird is I aired the tire to 60 and checked it. Fired it up and when the whistle starts it went right down to 40 in a minute. So I suppose I have to pull the CTIS cover off again. Doesn't seem like anything is leaking back there but when I soaped it last time the CTIS was disconnected. When picked up at GL that tire was an oddball tan on a green truck with a different tread pattern. The former owner said it blew out and he put the spare on but it would leak down after a few days. I put a valve in the tire and checked and it still leaked (CTIS disc) so it's probably an O ring. But the whistle is part of the
CTIS system, any thoughts?

 

[Suprman]

The system sends 12psi to hold the wheel valves open to air down the tires. If you have a fill side leak somewhere it can trick the wheel valves. Even though the valve body is sending full pressure the leak is venting out somewhere and around 12psi makes it to the wheel valve and you dump air. The sound you hear is probably air venting out the quick release valve since the wheel valve is opening to lower air pressure. Could be axle seals could be the lines under the truck. Look at all 3 quick release valves. Stick your finger in the boot over the vent hole. If it's really greasy inside you have a bad axle seal.

 

[Over]

The system sends 12psi to hold the wheel valves open to air down the tires. If you have a fill side leak somewhere it can trick the wheel valves. Even though the valve body is sending full pressure the leak is venting out somewhere and around 12psi makes it to the wheel valve and you dump air. The sound you hear is probably air venting out the quick release valve since the wheel valve is opening to lower air pressure. Could be axle seals could be the lines under the truck. Look at all 3 quick release valves. Stick your finger in the boot over the vent hole. If it's really greasy inside you have a bad axle seal.

are the 3 quick release valves in the cab? Wheres the boot?

 

[MtnSnow]

The quick release valves are found just behind the front grill by the hinge point on the drivers side for the front and near each of the rear axles. Just follow the air lines to them from the axles. The boot mentioned is covering the exhaust port on the quick release valves. If you pinch them the will open kinda like a duck bill