LMTV CTIS Question

1951M1078 · Nov 19, 2017

Anybody have photo's of the inside of the pcu ? Need to know what I will be looking at.
Thanks

Andyrv6av8r · Nov 19, 2017

I have new solenoids if you need them.

1951M1078 · Nov 19, 2017

Thanks Andy.

So I went for a 11 mile ride today. Went about 1/4 mile then the PCU started making air noises ? Looked at the ECU and I had a flashing HWY. light. Then a little more air sounds and then a steady red on the HWY light. About 1 1/2 miles all flickering ? Then more air sounds. Then back to steady red hwy light. about 3 miles more air sounds and still steady red Hwy ? Did this for about 4 miles. Then I look and all flickering ? All the way home ????

When the PCU made its air sounds I also could here the outside air dump's working.

Will check tire psi's in the morning.

Stellaevil · Nov 21, 2017

1951M1078 said:
Just started working on my CTIS. Not working. Some time I get the dash over speed light.?
But the best part is 5 lights "ON" !
Check the switch at the tank and it works. Adjusted the air up to 120 psi. Was at 90-100 +-.
Then drained the tanks.

Ran it for maybe 10 min's at 1500 rpm and saw the lights flicker then go out then Hwy.light only come on then nothing and back to 5 "ON" !

Check the dash harness all looks good.

I'm thinking it maybe best to go manual. PCU=$200-300 and the ECU is $300-500. But most parts are 15 + years old.

What do you guys think ?

Tires hold air ok, one seams to leak down more than others but their 2003's. Over a week will stay at 60 psi.

Any time the ECU has 5 solid lights it is malfunctioning. The lights should not flicker either. This is not caused by anything external it is a bad ECU.

Stellaevil · Nov 21, 2017

1951M1078 said:
Thanks Andy.

So I went for a 11 mile ride today. Went about 1/4 mile then the PCU started making air noises ? Looked at the ECU and I had a flashing HWY. light. Then a little more air sounds and then a steady red on the HWY light. About 1 1/2 miles all flickering ? Then more air sounds. Then back to steady red hwy light. about 3 miles more air sounds and still steady red Hwy ? Did this for about 4 miles. Then I look and all flickering ? All the way home ????

When the PCU made its air sounds I also could here the outside air dump's working.
Will check tire psi's in the morning.

5 lights on solid: Bad ECU
Lights Flickering: Bad ECU
Lights on then off by them selves: Solenoid fault maybe

Steady Highway Light: Good, system checks the pressures every 15 minutes and the highway light may flash when it's checking. If the tires were low, it will do a short inflation and then go back to the solid light. Flashing 1/sec Good, Flickering Bad

1951M1078 · Nov 21, 2017

After another trip it looks like the ecu is now working. I even took the chance and set it sand and down she went., Then back to HWY. and up she went.
Checked tire pressure at Hwy. and got 55 psi.

Would it take some on's and off's to get the system back after resetting the PSI ?

Will retest after I get the door handle reinstalled.

Coffey1 · Nov 21, 2017

Incorrect 5 blinking lights is not bad ecu.
5 solids are supposed to be bad ecu but have seen one 5 solid lights start working.
If the pcu is not sending the prober single to transducer and transducer tell the euc the prober thing it will fault out.

Andyrv6av8r · Nov 21, 2017

5 blinking lights doesn't mean that the ECU is bad. Loose wire/connector. I know that I have a bad pin in my connector and sometimes I get 5 blinking lights. After pushing in and reseating the connector, it always goes back to normal solid Highway light.

Stellaevil · Nov 21, 2017

No post says 5 blinking lights is a bad ECU. Flickering lights are not good.
5 lights on solid means that the ECU internal memory has been corrupted, that's not to say it won't eventually self correct but it is a bad thing and unreliable at best.
See Dana Troubleshooting Guide AXTS-0015, 2017. I wrote it, so if you find something that is incorrect let me know.

1951M1078 · Nov 21, 2017

evil, is their anything that I should look at for the flickering ? It almost looks like PC talk,code ? With luck it wont come back but ?

Stellaevil · Nov 21, 2017

1951M1078 said:
evil, is their anything that I should look at for the flickering ? It almost looks like PC talk,code ? With luck it wont come back but ?

The only things I have seen cause flickering is a stuck keypad or a bad ECU. I suppose an intermittent Swign or Gnd wire connection to the ECU might cause a flickering.

Scott z · Dec 5, 2017

Regarding the original 5 lights flashing scenario, I read this thread and others but none seemed to address my issue but I figured it out:

My symptoms were that the CTIS system seemed to be working but the 5 lights "rarely" stopped flashing. After testing and realizing how long it takes for the system to add air I realized that my only issue was a slow leak and that I wasn't driving it long enough to allow the system to air up all 4 tires.

As a test, I selected the sand option for lowest pressure. It took almost 5 minutes to reach that setting. When selecting highway again it took around 20 minutes to finally reach full pressure. I assume a bit of this was wasted on the slow leak (looks only slightly low after a couple of days) but either way it takes a long time and most of my drives were fairly short.

Stellaevil · Dec 7, 2017

Scott z said:
Regarding the original 5 lights flashing scenario, I read this thread and others but none seemed to address my issue but I figured it out:

My symptoms were that the CTIS system seemed to be working but the 5 lights "rarely" stopped flashing. After testing and realizing how long it takes for the system to add air I realized that my only issue was a slow leak and that I wasn't driving it long enough to allow the system to air up all 4 tires.

As a test, I selected the sand option for lowest pressure. It took almost 5 minutes to reach that setting. When selecting highway again it took around 20 minutes to finally reach full pressure. I assume a bit of this was wasted on the slow leak (looks only slightly low after a couple of days) but either way it takes a long time and most of my drives were fairly short.

Slow inflation is due to the engine driven compressors inability to deliver air volume at low engine RPM. If you are parked at any time and the system is still inflating run the engine wide open and that will dramatically shorten the inflation time. On a separate note; a slow inflation due to a leak should only log a 2 flashing light fault indicating the two mode pressures it is stuck between, not a 5lt fault.

Awesomeness · Dec 7, 2017

Stellaevil said:
a slow inflation due to a leak should only log a 2 flashing light fault indicating the two mode pressures it is stuck between, not a 5lt fault.

Are all the different flashing faults described in the manual? I don't think I've run across that before.

Stellaevil · Dec 7, 2017

Awesomeness said:
Are all the different flashing faults described in the manual? I don't think I've run across that before.

All the faults are listed with the associated flashing.

Sgthoffer · Dec 7, 2017

Can you guys watch this 2 minute video and let me know what you think is going on?

I bought this LMTV with CTIS unplugged. The guy I bought it from said it was unplugged when he bought it and he never plugged it in.

I plugged it in tonight after reading this entire thread. I then recorded this video from a cold start with no air pressure in the tanks.

Any help would greatly be appreciated.

https://www.youtube.com/watch?v=U2Zb9CQM_2o

Stellaevil · Dec 8, 2017

I cannot give advice on behalf of the company I work at for obvious legal reasons but I don't mind using my knowledge of the CTIS product to help everyone here. I have 27 years on all US based military vehicles using the Eaton/#### systems. Mechanical and electronic test lab technician to applications engineering. As these threads continue to expand I will continue to post the AXTS-0015 (2017) Troubleshooting Guide. Just Google it. Parts can be very expensive so identifying the problem is critical.

Stellaevil · Dec 8, 2017

Sgthoffer said:
Can you guys watch this 2 minute video and let me know what you think is going on?

I bought this LMTV with CTIS unplugged. The guy I bought it from said it was unplugged when he bought it and he never plugged it in.

I plugged it in tonight after reading this entire thread. I then recorded this video from a cold start with no air pressure in the tanks.

Any help would greatly be appreciated.

https://www.youtube.com/watch?v=U2Zb9CQM_2o

Sorry but the ECU is bad.

Sgthoffer · Dec 8, 2017

Stellaevil said:
Sorry but the ECU is bad.

Thank you for the reply. I am sad.

Sgthoffer · Dec 8, 2017

Where can I buy a NOS or working used CTIS ecu?

LMTV CTIS Question

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