Community Forums

max77713 · 06-25-2015, 05:15 PM

my check engine light has come on. my coach is running great, checked oil, water and all is great, what could cause it to come on

Tha_Rooster · 06-25-2015, 05:24 PM

What kinda coach? I really doesn't matter the only way to find out is hook it up to a computer reader anything else would be guesses.

twinboat · 06-25-2015, 05:37 PM

He has a 2000 Newmar Mountian Aire. 40 ft.

It's in his info.

jacwjames · 06-25-2015, 05:45 PM

Do you have the ability to get codes off the engine. Could be just about anything, really no way to tell without codes.

Tha_Rooster · 06-25-2015, 05:58 PM

Quote:

Originally Posted by twinboat

He has a 2000 Newmar Mountian Aire. 40 ft.

It's in his info.

Thank you but not very helpful.

dennis45 · 06-25-2015, 06:52 PM

Quote:

Originally Posted by max77713

my check engine light has come on. my coach is running great, checked oil, water and all is great, what could cause it to come on

Welcome to the forum. Since you are new, I'll give you a tip, go into user CP and edit signature and put in all the information on your coach/toad etc. then when you post with a question, folks will know what you have and be able to respond with better information that is pertinent to your coach.

dennis45 · 06-25-2015, 07:03 PM

There has been a ton of discussion on the subject of CEL. I have bee plagued with this problem since I owned this coach and I'm not alone. I had mine into Cummins and they could not see any fault codes in the life of the engine. They did not have an answer.
A couple of times I thought I had it licked only to have a check engine light come on again a few thousand miles later.

On the bright side, when it comes on, it only de rates the engine slightly so I keep on going (with that annoying buzzer blaring) and find a spot that is safe to pull over. Shut the engine off, let it sit for a couple minutes, restart and off we go. Might not see it again for thousands of miles. Or could be a few hundred.
One thing I have read lately, and I may be guilty of, is not waiting for the WAIT light to go out on start up. I have read this will upset the ECM and it will cause a CEL at some point. That's my new mission, so we will see.

Hope this helps shed some light on your problem. You're not alone.

Skip426 · 06-25-2015, 07:29 PM

[QUOTE=max77713;2620562]my check engine light has come on. my coach is running great, checked oil, water and all is great, what could cause it to come on[/QUOTE

As others have mentioned , there are over a dozen possible causes for the check engine light , some will cause the engine to de-rate to as low as 100 HP just to allow you to get off the road, others will just keep the light on, telling you , there is maintenance required. SOME will shut the engine off!
Without the active code , and info on the engine type, Cat ? Cummins ? and size, the members here in the forums are just as in the dark as you are.

Many RV owners , have installed , Scan Gauge or Silverleaf on dash displays to allow them to get the codes and erase them after the cause has been dealt with.

SilverLeaf Electronics, Inc. | Knowledge is Horsepower?...

ScanGaugeD - Advanced J1939 & J1708 compatible Vehicle Monitor for Diesel Pusher Vehicles : Linear Logic

BadBoy · 06-26-2015, 06:10 AM

Check your gas cap is on tight.

I had a similar problem and discovered this simple fix. Hoping it's as simple for you!

dennis45 · 06-26-2015, 08:09 AM

Quote:

Originally Posted by BadBoy

Check your gas cap is on tight.

I had a similar problem and discovered this simple fix. Hoping it's as simple for you!

Thanks for that one, I actually replaced both caps and guess what, a couple thousand miles later, CEL. NO CODES.

Skip426 · 06-26-2015, 08:56 AM

Quote:

Originally Posted by dennis45

Thanks for that one, I actually replaced both caps and guess what, a couple thousand miles later, CEL. NO CODES.

Wouldn't be your issue, diesel engines don't run the same, evaporative emissions system as gassers, and so no monitoring, of the fuel tank, that would cause a CEL.

dennis45 · 06-26-2015, 09:12 AM

Quote:

Originally Posted by Skip426

Wouldn't be your issue, diesel engines don't run the same, evaporative emissions system as gassers, and so no monitoring, of the fuel tank, that would cause a CEL.

Absolutely, I changed the caps because the ratchet on one broke so replaced them both. I was not expecting any change to my CEL issue.

That said, I'm still convinced it is an intermittent electrical issue that cause a blip to the ECM but not enough to register a code. Also thinking along the lines of the Crank/Cam Position Sensor. One of these days when I get a roundtoit, I'm going to remove the pick up and see if there is any metal debris on the end. That will take a little a little motivation.

bobmac · 06-27-2015, 10:51 AM

My experience with my Cummins ISB on a Freightliner chassis is that the LBCU does not capture all engine codes unless they have become a solid trouble that affects engine performance. By the time you find them on the LBCU, the engine performance will likely be affected. I talked to the Freightliner help line and they confirmed what I had observed.
I purchased a Scangauge-D after good experience with the one in the car. I recently noticed that I was getting codes on startup that the ScanGauge detected but were not recorded in the LBCU. I recently detected a code for the turbo actuator that would flash the CEL for a second or so but was only captured by the ScanGauge. After receiving several codes, I took the coach to Cummins and after troubleshooting, the turbo had to be replaced. The engine reports an actuator issue in advance of full turbo failure. The ScanGauge saved me several thousand of dollars as my 5 year warranty is expiring next month.
I also had the same code experience before my EGR valve failed but did not act until it stuck open. My conclusion is that if you are seeing the CEL, find out what is causing it - don't ignore it and consider getting a code reader so you know what is being reported. In my case, it has more than paid for itself and I haven't been left stranded on the side of a highway.

Dutch Star Don · 06-27-2015, 11:43 AM

"dennis45"....I had a Cummins ISL in a 2005 Diplomat that went 77K without a blip. I buy the new Dutch Star on a Freightliner chassis and on the first trip I get a CEL. Just as I got home, it had cycled enough that it went out. Next trip I get it again. This time I took it to Cummins and see that it's an over temp code of the EGR. After several hours of resetting and tripping other codes, they say it's fixed. Now I'm getting gun shy.

After the second repair I read where many wait until all of their gauges sweep before starting. I started this practice and no more lights. A few months later we were leaving Yosemite and had to stop along the side of the road to wait for the daughter in her RV. When I saw them coming I rushed to start the coach, didn't wait for the gauges to sweep and sure enough, the CEL came on. It went off a few minutes later. The theory about waiting for the computer makes sense. My last Cummins didn't have all the extra electronics related to emissions, such as DEF systems. I'm sure the time frame for the computer to run all of it's checks is longer than before.