Check engine light on....

SaltLife · 07-12-2019, 06:59 PM

Took the Ultimate Freedom out to dinner. About 20 mins 8n the check engine light came on with the steady alarm. All the gauges looked good. Got to our destination and checked the oil. It was on the add mark. I had been running the generator with the AC running. Turned the gen off, but didn't make a difference.

Shut the motor down, started it back up and no light. Doesn't mean it wont come back on going home...

Not sure what's going on.... Help!

SaltLife · 07-12-2019, 09:05 PM

Well, on the 30 mile ride home, no engine light...

homeless · 07-13-2019, 06:11 AM

I have had off and on engine light for over a year now with no understanding yet of what makes it come and go. I thought it might be the air cleaner but didn't seem to help....

SaltLife · 07-13-2019, 07:17 AM

If it keeps happening I'll bring it in and have the code checked. The alarm is obnoxious.....

armullis59 · 07-13-2019, 07:52 AM

Try buying one of these to check your coach!

https://www.amazon.com/dp/B00652G4TS...v_ov_lig_dp_it

Jim_HiTek · 07-13-2019, 12:34 PM

Remember all the sensors have connectors and there are inline connectors going up to the dash. With an intermittent like that, I'd clean, remove, contact spray, reconnect/disconnect several times any and all connectors I could find starting at the engine's ECM. I'd also chase the wiring bundles and make sure none of them have been worn through.

I looked at that OBD II device link shown above and I didn't see where it said MD, HD (Medium and/or Heavy Duty). That's what a truck chassis requires in a OBD II reader, that HD designation for them to display the problem codes correctly.

This one would probably work: XTool

Might need a Y adapter if you have one of the older 7 or 9 pin protocols for truck chassis.

SaltLife · 07-13-2019, 02:43 PM

Thanks. Just drove 2hrs and nothing, heading back today too

Poppab · 07-21-2019, 04:52 PM

My 8.1L engine check light 2x was knock sensor on right bank. Replaced since first time (OBD II reader) and second was wire connected to the same sensor came loose. Pushed it back on with no further issue. Knock sensor essentially is a microphone listening to internal engine combustion to let you know engine isn’t firing correctly for some reason.

David K · 07-21-2019, 04:53 PM

I have a 2002 Ultimate Advantage --- had this happen one time --- the coolant level was low on mine. You might want to check both the overflow tank and the coolant tank at the rear by the engine. Not a real "biggie" but, had me puzzled for a while until I found the problem. It may have not went off during the return trip as the hot coolant had expanded and the sensor was not sensing a low coolant at that time.

depchief · 07-21-2019, 05:07 PM

I have had in the last few months a number of Check Engine lights and they where all caused by a loss of coolant. I finally figured they where all caused by the heater core leaking. This came to light after I finally smelled coolant while driving.

So check the area around the top of the generator for a build up of water with a tint of the color coolant.
I bypassed the heater core, end of the problem.

Check your little sight glass on the surge tank to make sure you have the proper coolant level, and the recovery bottle is at proper level

BobT · 07-21-2019, 05:56 PM

I have had the Check Engine Light on in my 2004 Adventurer. Usually I start out fine but about a half hour after filling up the light comes on again. The gas cap says to turn three clicks and I try to keep it turned that way. Sometimes I stop open the gas cap and open the filler tube to vent any fumes that might have built up and then seal the cap three clicks. The cap is just over a year old but I have had the problem from the start with the new cap.

On the last trip a couple of weeks ago the light came on at engine start up after sitting for a few weeks. I had checked all of the fluids and made sure they were at the appropriate level before starting up. Light stayed on for the entire 45 minute trip.

Blubugger · 07-21-2019, 06:39 PM

If you have ANYTHING that has an OBD2 port, you need an OBD2 reader....they range from relatively simple and inexpensive on up. But for the price of one charge for a diagnostic repair facility to read the code...you can get piece of mind while on the road and ascertain if the problem is critical [low oil or not [loose gas cap]. Just get one that will fulfill your enquiring mind. The days of the check-engine-light meaning loss of oil or oil pressure is over. There are a plethora of critical codes that need to be addressed immediately, and others that will need future attention.

imnprsd · 07-21-2019, 07:04 PM

If your engine flashed a "check engine" light then your ECM should store that code in memory by date and time. This called a "soft code" because the engine cleared itself.

I really think you should find out what that code is, because your engine electrical or fuel system just spoke to you!

And to ignore this "chatter" may leave you stranded out on the highway someday.

...And just because you can go for months (maybe even years) without seeing another code you need to "keep tabs" on your engine and decide if preventative maintenance is warranted.

You can also pull into any number of repair shops when you are traveling, or better still you can go to your local diesel mechanic, and they will scan for codes and clear your codes at no charge. (Ask if they charge to scan first.) Just don't let them clear you fault codes until they give you the history.

Then you can determine if you have a fuel deliver concern or an electrical concern; and you can decide what to do about it before you get stranded.

This happened to me twice and both times it took over 3,000 miles for me to ascertain the "root cause" of the soft code that got tripped 6 months earlier.

Your engine is talking to you... Don't ignore it. My advice is to:

A) Buy that scan tool for "Large Trucks" and scan your soft fault codes yourself... for the rest of your RVing days; or...

B) Go to a diesel repair facility as soon as it is convenient.

Don't just assume you can ignore your engine soft codes just because your engine is running fine, because it may not be. Or you may have a boarder line problem your ECM detected once, but not again.

Good RVing to you and to us all!

TeJay · 07-21-2019, 08:34 PM

I read through most of this thread an nobody mentioned this aspect of the CEL.

The only time the CEL is lit is if or when something occurs which causes the emissions to exceed their set limits. That's it!!!!. Yes you can read the codes and don't forget the code is a symptom of a problem. It does not tell you which part to change. It's no different than going to the DR. You sometimes see a DR because you are ill and you tell them the symptoms. They check your vitals and maybe run tests to determine what you have and how to treat you.

If what caused your CEL was a intermittent stuck relay and it somehow fixed itself the CEL may go out and not return. If what caused the CEL does not occur after a certain number of starts the code will be erased. Many of us have failed to tighten the gas cap and when the system ran a vacuum test the CEL would come on. That's an evaporative system failure and needed fixed.

If the CEL comes on and stays on it's a hard code. It still only means you are exceeding your emission standards as set by the GOV. It does not necessarily mean you are going to shut down or just stop running. If something as simple as a vacuum line comes off it will set a code. That leans the mixture and maybe the system can't compensate or adjust. That can cause an engine to run hotter and needs looked at and again fixed.

puttin · 07-22-2019, 10:22 AM

Good stuff Tejay...and great job withe CHF as well!

SaltLife · 07-22-2019, 04:38 PM

Thanks for the replies. Since I shut it off and then went on a 4hr trip it hasn't come back on, yet.

I know if my pickup CEL comes on but doesn't flash, it's something minor. If it flashes, then you need to pull over pronto. Not sure if the RV works the same way.... I'm going to assume not... But if it does, I'll be pulling over..

dickb46 · 07-22-2019, 05:57 PM

You can use your speed control to check engine codes. see your engine manual

SaltLife · 07-22-2019, 06:56 PM

Thats cool. I learned how to increase idle speed by using the cruise buttons...

wwr · 08-08-2021, 11:15 AM

i have a 05 itasca 38j with 8.1 check engine light came on cked codes 131-151 lf and rt o2 sensors low voltage found exhaust lk changed donuts and senors reset computer test drove about 90 miles cel came back on 131-151 again. no leaks of any kind water temp normal big lose of power rest obd and came back home. this has happened twice and now dont know where to go help

SaltLife · 08-08-2021, 11:37 AM

This thread is 2 yrs old, I would start a new one with your issues ...