Unexplained high idle Cummins ISB 6.7

[Rich W.]

After moving the coach yesterday to pack for our Coastal trip, the idle went up to around 1100rpm. No dash lights, no codes, no indicators of any kind, but it was persistent. I played around with the cruise control buttons raising and lowering the idle, but after getting it down to 800 or so it would climb back up to 100. I shut it down, restarted and it did it again. I used OTR diagnostic to see what was going on and there was no evidence of regen and my soot level is at 0%. After a while it went back to normal and stayed there. Anyone else encounter this. Get any answers? What am I missing? I’ll run it again today and see what happens.

 

[Neal]

I believe I've seen that once before. I left it alone and it came down on its own. Probably best to not interrupt it.

 

[Neemer]

Was your dash a/c on? Mine idles at 1200 if the a/c is on and the parking brake is engaged.

 

[Rich W.]

Not sure on that - I’ll check when I run it today. It might have been.

 

[Rich W.]

Dash AC raises it about 25-30 rpm. This was more like 300 - regen territory. So….I don’t know.

 

[JRW-NAW]

In our 2018 Ventana 3412, the ISB would idle around 1200 rpm when the dash air was on.

 

[Rich W.]

In our 2018 Ventana 3412, the ISB would idle around 1200 rpm when the dash air was on.

OK I’ll chalk it up to that but its never done it before. Had two very nice, uneventful, trouble free days on the road so far on this trip so I’d say all is well. Yes, I’m knocking on wood….

How’s the “down sizing” working out?

 

[JRW-NAW]

OK I’ll chalk it up to that but its never done it before. Had two very nice, uneventful, trouble free days on the road so far on this trip so I’d say all is well. Yes, I’m knocking on wood….

How’s the “down sizing” working out?

So far GREAT! We leave tomorrow morning to go back to Denver...excited to get it on the road.

 

[Neemer]

So far GREAT! We leave tomorrow morning to go back to Denver...excited to get it on the road.

Pics or it ain’t happening.

 

[Bayouownbeer]

Mine will idle on its own when I first crank it from being cold. Like a warm up idle then it will come back down.