Transmission Light coming on and all lights flashing on stick

[TruAg]

I recently purchased an M923A2 Cargo Truck. Brought it home and ran just fine. Still runs great, but the dash transmission light is blinking as are all the lights on the automatic stick. Fluid level in transmission is fine and runs, shifts great. Has anyone had this problem? Could a sending unit be bad on the transmission? Wiring issue? Any help would be appreciated.

 

[R Racing]

This should probably be in the 5 ton section. Does the truck still drive ok ?

 

[doghead]

Flashing light next to the shifter sounds like CTIS.

 

[dawico]

Flashing light next to the shifter sounds like CTIS.

This.

What light is flashing?

 

[Plugugly]

Is it the yellow "overspeed" light on the dash that is blinking? The ones on the shifter column flashing in red sound like the CTIS system, as others have said. The overspeed light and CTIS are linked, if your going faster than the tire pressure you have selected via CTIS, the yellow light will flash. If I understand the system correctly, it will also raise your tire pressure to the next higher one until it the speed and pressure are what it thinks are appropriate. Above 55mph (more like 60 in my truck) it will blink because that's faster than it thinks you should go in Highway, and it can't raise it anymore than that.

 

[TruAg]

Truck runs fine and no problems with the automatic transmission, such as hard shifts or hanging in a lower gear.

The light on the dash that is flashing is labeled "Trans oil." I was going 60 mph, so maybe it is just the CTIS.

On the shifter, it is all the red lights beside what CTIS selection. I selected Hwy, but suspect I have CTIS issues. System is not keeping the tires properly inflated. Air pressure is good, just not getting to tires.

Looking through TM today for trouble shooting CTIS. Thanks!

 

[Rmtaunton]

I will give you two guesses what that guage under the flashing light does.

The light you are referring to is your over speed light, it will come on at 55. As far as your ctis lights, let truck build air to 120 or above and shut off . Next restart truck press the run flat button, then after about two minutes hit the hwy button.

As for tonight start reading your TM's starting with the operating procedures to get familiar with how to drive and understand the features on the truck.

 

[Plugugly]

Truck runs fine and no problems with the automatic transmission, such as hard shifts or hanging in a lower gear.

The light on the dash that is flashing is labeled "Trans oil." I was going 60 mph, so maybe it is just the CTIS.

On the shifter, it is all the red lights beside what CTIS selection. I selected Hwy, but suspect I have CTIS issues. System is not keeping the tires properly inflated. Air pressure is good, just not getting to tires.

Looking through TM today for trouble shooting CTIS. Thanks!

The label "Trans Oil" belongs to the gauge beneath it, the light is Over speed. There are no lights on the dash that flash other than ABS and Over Speed.

 

[doghead]

The basic operators manual is, TM 9-2320-272-10

In it you can find info like this...

 

[doghead]

Also make note that you are probably exceeding the speed rating on your tires when they were new.

I doubt they are new now.

 

[TruAg]

Found description in TM. Thanks

I am sure I was exceeding the speed rating on the tires, was pushing 60 - 65 on the drive.

 

[TruAg]

Page 1 - 72 was good too. Thanks

 

[Rmtaunton]

Now your getting the hang of it

 

[dawico]

There is a ton of good info in the TMs even if you aren't really looking for something specific. Glad you got it figured out.

 

[TruAg]

Plan on following TM instructions on CTIS tonight. Hoping disabling and resetting CTIS will fix light flashing on the ECU. Reading is our friend. Thanks for the pointers.

 

[TruAg]

Well, after reading and following the TM, I still have flashing lights on the ECU. Disabled and re-set it as TM explained. I may have a bad ECU. Anybody know where I can find one? Is it essential?

 

[MtnSnow]

I would suggest going thru the troubleshooting section for the CTIS to determine what needs to be fix/replaced before just throwing parts & or guesses at it.
View attachment AXTS0015 - Spicer CTIS (Central Tire Inflation System).pdf

 

[todds112]

One thing that jumped out at me reading the trouble shooting guide is they flat out say it is rarely a bad ECU.

 

[1 Patriot-of-many]

Like others said, hold down the run flat button for a couple seconds see what it does. Second if there is one tire that is flat and that doesn't help, take off the connector and see if there is a shrader valve in the vale stem. Third probably a solenoid is bad on the pneumatic unit. Test as per the CTIS manual posted by MtnSnow. Lots of guys here part out trucks, you can pickup any parts you might need reasonable usually.