Forum Discussion

John___Angela's avatar
Oct 14, 2014

Resolved. I have a scangauge code Cummins doesn't recognize.

SO. Got my scangauge to check out the check engine light code on my ISC350 CAPS. The code is ID 18 and FM 11. Talked to Cummins and they could only suggest I take it to a Cummins dealer, which I will, probably in Vegas.

Also the code clears but the light doesn't go out. Having said that the code comes back pretty quick after so it might be a continuous thing.

The motor starts and runs fine. We are not stranded but I am fairly convinced it is de-rated as it seemed fairly gutless on the hills up at 8400 feet in Bryce.

Below is the resolution but it is also repeated in a later post.

OK. In keeping with my promise to post the resolution, here goes. We quite honestly have been busy with other things so I haven't had a chance to look at this problem. But we are on the road trip again in a few weeks so I thought I would give it a shot before taking it to Cummins.

So a little history. My seargent major told me a long time ago to always record the readings meters and indicators on equipment when things are running well. That way when things are not running well you can see whats changes. You won't remember or recognize subtle changes when things deteriorate. To that end, 11 years ago when we bought the coach I took a permanent marker and marked ALL the gauges on the dash as well as took key point specific readings of various values and marked various areas with a label maker for what are normal values in specific operating conditions. So, when the alternator voltage started to slowly drop over the last year I wondered what was happening. On the last trip the voltage was down around 12.9 on the meter although STILL READING OKAY DIRECTLY ON THE BATTERIES. Probably because of the solar array. Who knows. Anyway. Today I got under the bed and went straight for the alternator connections. One of the connections (found out it was the positive when the sparks flew after grounding the wrench) was corroded. It was tight but I mentioned to loosen and clean it somewhat and re-tighten it. (It still needs a better cleaning) Fired it up, noticed the voltage on the meter back to where it is marked from 11 years ago, tried to clear the code with the scan gauge AND THIS TIME THE CODE CLEARED AND THE LIGHT WENT OUT. I'm not happy with the posts on the alternator and it need to be completely removed cleaned and put back in but this should hopefully solve the problem in the meantime. I'm recovering from an injury and didn't want to spread myself out on the engine any more than I had to.

Hope this helps the next guy.

Cheers.