CTIS over speed lamp lights up

[Hobie_rat]

Hi guys, I have a 98 M1078. Does anyone have an idea as to why and/or how to correct this problem. While driving, when I reach 30 mph the CITS over speed light comes on

 

[Suprman]

Is your speedo smooth and correct?

 

[KN6KXR]

My experience is only with the M939A2 system so take this with a grain of salt.....

Suprman is correct what he's alluding to is the speedo pickup. There's a generator that sends a signal to the CTIS system. Make sure that's working correctly. Every inflation pressure has an overspeed warning setting for that pressure.

If it's always done this your settings may be wrong in the module. You can set the warning by interfacing with the module via laptop. On my truck I had to use a 24V Dearborn adapter and the J1939 protocol then I could use the Dana software (free download) to change the settings. The overspeed is different than the tire inflation. I got the Dearborn adapter and cables from a surplus STE/ICE kit. Best value I could find.

I think later trucks (other than the M939A2 series I have to work with) have the communication cables already setup. For mine I had to make a 26 pin male/female "interrupter" cable and breakout the pins I needed into an adapter. AFAIK the CTIS ECU modules are similar besides programming and faceplate label orientation. If I come across a free one someday to bolt in and test I'll be able to answer that question.

Good luck lots of info on the site about it.

 

[DeMilitarized]

My experience is only with the M939A2 system so take this with a grain of salt.....

Suprman is correct what he's alluding to is the speedo pickup. There's a generator that sends a signal to the CTIS system. Make sure that's working correctly. Every inflation pressure has an overspeed warning setting for that pressure.

If it's always done this your settings may be wrong in the module. You can set the warning by interfacing with the module via laptop. On my truck I had to use a 24V Dearborn adapter and the J1939 protocol then I could use the Dana software (free download) to change the settings. The overspeed is different than the tire inflation. I got the Dearborn adapter and cables from a surplus STE/ICE kit. Best value I could find.

I think later trucks (other than the M939A2 series I have to work with) have the communication cables already setup. For mine I had to make a 26 pin male/female "interrupter" cable and breakout the pins I needed into an adapter. AFAIK the CTIS ECU modules are similar besides programming and faceplate label orientation. If I come across a free one someday to bolt in and test I'll be able to answer that question.

Good luck lots of info on the site about it.

Can you point me in the direction for a more in detail forum on how to change settings on a m939a2 ctis unit?

 

[Hobie_rat]

Is your speedo smooth and correct?

Hi. I believe so, the needle appears to be smooth but, correct? Not sure, I was keeping up with traffic. I finally got my title and insurance so today was the first time I had it over 25 mph and out of the neighborhood. I counted it shifting into fifth gear. As I passed 30 mph the over speed light cam on. What would cause this? A bad sensor? Is there anyone in the Raleigh, NC area that can plug in and check the settings on the CITS

 

[Hobie_rat]

Can you point me in the direction for a more in detail forum on how to change settings on a m939a2 ctis unit?

Thanks for replying. I’m new to this so… where is the generator and its location. I don’t yet have TM’s

 

[coachgeo]

Thanks for replying. I’m new to this so… where is the generator and its location. I don’t yet have TM’s

bellhousing. Some issues in trans , tach and ctis end up that magnetic pickup so you should check it anyway. How to adjust it is also in TM's

TM's can be found here on this site. Very first forum on the very first page of this S.Soldier Discussion Board is a forum named.... Technical Manuals. (funny that). If it twas a ... itt a bitten ya.

 

[Third From Texas]

Does your CTIS controller function?

Does the issue persist if the CTIS controller is unplugged (best to always plug/unplug the controller with ignition OFF)?

 

[GeneralDisorder]

Older CTIS modules communicate with J1587. Newer one's support J1939. The DANA software supports both you just need any RP1210A protocol adapter.

Tire Pressure Management | Dana Commercial Vehicle

Dana offers a highly efficient, tire-pressure monitoring system featuring premier tire inflation technology to provide enhanced mobility in tires for vocational, linehaul, and military applications.

global.dana.com

This should work, although I haven't tried it personally:

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That should also work for CAT ET, etc since it also uses RP1210A

 

[chucky]

The first trip in my truck kind of the same thing but my horn went off and kept blowing and of coarse i was on a 2 lane road so the folks out in the front yard al started waving like i was blowing the horn intentionaly but stopped after i unplugged the controller !

 

[KN6KXR]

Can you point me in the direction for a more in detail forum on how to change settings on a m939a2 ctis unit?

Thread in the sub forum someplace. I replied to it maybe search my posts with CTIS in the subject. IIRC it was 98G that did all the footwork on the parts. I then ordered them and made a breakout cable with the pins I needed then wired them to the correct plug. It's a 26 pin male and female (same as the back of the CTIS module). The trucks were never wired to talk to them so you have to homebrew. Later trucks you can just plug in. Software is free.

 

[KN6KXR]

Hi. I believe so, the needle appears to be smooth but, correct? Not sure, I was keeping up with traffic. I finally got my title and insurance so today was the first time I had it over 25 mph and out of the neighborhood. I counted it shifting into fifth gear. As I passed 30 mph the over speed light cam on. What would cause this? A bad sensor? Is there anyone in the Raleigh, NC area that can plug in and check the settings on the CITS

The over speed is set for the tire pressure you are at. Each mode (HWY, XCNTRY, SAND) has an overspeed setting. So it could be a bunch of stuff. Like maybe your tires aren't inflated to HWY? Speed sensor, ECU, software..... Check your tire pressure first. Maybe then pressure transducer (tells the system the pressure), then speed sensor, then swap ECU, then software interface....

 

[KN6KXR]

Older CTIS modules communicate with J1587. Newer one's support J1939. The DANA software supports both you just need any RP1210A protocol adapter.

Tire Pressure Management | Dana Commercial Vehicle

Dana offers a highly efficient, tire-pressure monitoring system featuring premier tire inflation technology to provide enhanced mobility in tires for vocational, linehaul, and military applications.

global.dana.com

This should work, although I haven't tried it personally:

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That should also work for CAT ET, etc since it also uses RP1210A

That's a good deal. If I didn't have an STE/ICE kit I picked up super cheap I'd get that.

 

[Hobie_rat]

Does your CTIS controller function?

Does the issue persist if the CTIS controller is unplugged (best to always plug/unplug the controller with ignition OFF)?

Thanks I’ll give that a try

 

[Hobie_rat]

Thanks I’ll give that a try

It does inflate and deflate as I push the different setting. The controller on the vehicle when I bought it blew the hwy setting. I got a new one and appeared to be working well

 

[flyfishtrailer]

It does inflate and deflate as I push the different setting. The controller on the vehicle when I bought it blew the hwy setting. I got a new one and appeared to be working well

Is your new one black or was it listed as an MRAP controller? If so, it will do that overspeed thing even though it is working fine. The controllers that were programed for different vehicles have different set points (55 PSI is highway on LMTV, but MRAP is 80ish). I replaced mine with an MRAP on purpose to get higher inflation to help squeeze the MPG a little (and I couldn't find an LMTV CTIS controller as cheap as the MRAP). There is nothing wrong with my CTIS system, except that I get the overspeed warning because of the different settings.

 

[GeneralDisorder]

Is your new one black or was it listed as an MRAP controller? If so, it will do that overspeed thing even though it is working fine. The controllers that were programed for different vehicles have different set points (55 PSI is highway on LMTV, but MRAP is 80ish). I replaced mine with an MRAP on purpose to get higher inflation to help squeeze the MPG a little (and I couldn't find an LMTV CTIS controller as cheap as the MRAP). There is nothing wrong with my CTIS system, except that I get the overspeed warning because of the different settings.

There's no need to replace the controller. You can program all the settings including overspeed set points with the free Dana diagnostic tool.

 

[Ronmar]

The vehicle speed sensor is in the transfer case. That sensor is processed thru the transmission control unit which then delivers it to the speedometer and CTIS.

I suspect that as mentioned, your CTIS is programmed for a different military vehicle with a different pulse per mile rate than the LMTV.

you can do one of 2 things. Find someone to reprogram it. Or you can disconnect the speed input from the CTIS controller. Down in the dash there is an intermediary connector P111. Pin B on that connector is the speedometer pulse input. you can also reach it at the back side of the speedometer and disconnect it there, and of course at the CTIS connector itself. It is pin U on that connector. I like P111 because you can simply remove pin B from the connector shell and insulate it without having to cut any wiring(easily reversible).

the signal goes from sensor to TCU to speedometer connector to P111-B to CTIS connector at the controller.

 

[spankybear]

What color is your control box? If it is black it is programmable... You can set the speed to flash over speed at any speed. The Washington National Guard sets there to 35 MPH... You will need to have a "y" cable, interface and a computer.