primary and secondary air pressure alarms

[chhiii45]

On my retrun from a 3 day trip a few weeks ago I kept getting low air pressure alarms from both my primary and secondary gauges. The pressure would drop to 0 and eventually the pressurewould come back. If I turned the coach off and restarted, the problem would disappear for a while but return.

Any ideas of what might casue this problem and what the cure might be?

[Luckiest Dreamer]

on my recent trip the primary would drop to 0 and quickly return to full pressure. That indicated to me that it was not a pressure problem since recovering the air that quickly was impossible. As it turned out the gauge was bad. It could also be as simple as a loose wire.

[David Bott]

Oh My, let me guess, it is a Freightliner? I say this for we have a 08 TM which is on Freightliner. We have been dealing with this issue for over a year. We have tried new gauges, resetting the wires, flashing the firmware of of ICC (ICU?) and even replacing the ICC (ICU?) and again flashing the firmware. All with Freightliners help of course.

1) It is more than likely not the gauge.

2) It could the the white wire harness as they had some issues with them loosing connection. You can take off the cover the that holds the gauges and re-seat the wires. Then you can do the same for the ICC. (ICU?)

3) Get the firmware flashed to ver 1.45...At least that is what ours took. (Not sure on your engine or system as it was not mentioned.) Prior to 1.45 they had a data stream timing issue. Once out of wack on timing, the alarm will come and go until the engine is tuned off and back on to reset the unit. 1.45 is suppose to fix this issue.

As of now with the new ICC and the new firmware, I thus far am doing OK. At one time we just did the new firmware and I was good for over a month or so, then it game back again. So they wanted to replace the ICC. They did, I had the issue before I left the lot, and then I asked them what firmware was on it...1.42. They flashed to 1.45 and so far, well, so good. Note however, we did also remove and reattach all the white wire leads to be sure.

All in all, they are not 100% on it. It affects some, but not all.

I have a 2008 TM with a Mercedes 900 engine.

[GO BLUE]

Mines has done that lots of times.....I just bang on the dash......................jim k