Yellow warning light came on in dash cluster 330 ISC cummins

[mikee409]

The engine is a 2001, 330 hp Cummins ISC.
No ideas what it's indicating. all fluids are up to level. Changed all filters 4500 miles ago. Engine runs good with good power. Only issue I see is the engine temp. rises when ascending a small grade.
Question, could the coolant filter being clogged cause the light to come on?
Coolant filter was changed 1 year ago.
Question, could low hydraulic pressure to the fan and steering cause a warning light to come on? I changed the oil and filters 3 days ago.
This same light came on several months ago but went out within 5 min. Have made several 2 hour trips without the light coming on.
Any help is appreciated. Really don't want to drive 1hr& 20 min to Houston just to have the code read. Mike

[dennis45]

Most of your scenarios would not cause a Check Engine Light with the exception of Low Coolant or a faulty Low Coolant Sensor which is located in the side of the coolant expansion tank. The coolant filter is a by pass filter. If it were plugged it would have virtually zero effect on the cooling system performance.

My guess is if you plugged in to the ECM there would be no codes showing. When you get the CEL I'm also guessing you may notice a slight de rate in power but the engine runs OK. If you pull over, shut down, wait for a bit and restart, the light clears and you are under way again.

I have gone full circle with this issue on mine for a few years. After trying many attempts at curing the problem, the best fix I have found is to make sure to allow the WAIT Light to clear before you start the engine. Once I began to pay more attention at start up, I have not had a CEL in over 10K miles.
Even if you shut the engine off for a minute and then restart, make sure to let the light clear before starting.

The other possible cause is an intermittent low voltage or poor connection issue that will cause an intermittent power loss and trigger the CEL.
This issue can be a challenge to locate.

[jimmy braden]

Originally Posted by dennis45

The other possible cause is an intermittent low voltage or poor connection issue that will cause an intermittent power loss and trigger the CEL.
This issue can be a challenge to locate.

Replacement of ground straps to motor?

[mikee409]

Dennis, thanks for reply. I let the rv set over night and allowed the full startup cycle to run. The light will not go off. Guess I'll try to clean the coolant sensor.

[mikee409]

Jimmy thanks for the reply, will check the ground straps tomorrow.

[dennis45]

Sorry, I thought you had the intermittent CEL.
If yours is on continually it should be easier to find the cause by reading the codes off the ECM.
I would find a Cummins dealer or truck shop that can connect to the ECM. Since it has not cleared, it should point you to the fault. Otherwise it's like looking for a needle in a hay stack.

[AFChap]

You say the light is yellow. But what shape is it? My warning lights all have a distinct shape that is very helpful in discerning what it relates to.

[mikee409]

Paul, it's shaped like an upside down light bulb.

Found a local guy that had a code reader today. He could clear the past history codes but code #18 would not clear. It's labeled "fuel control valve"
I can't find this code on the "Cummins code section" on a google search.
Not sure how to proceed

The local guy really didn't want to work on my RV. He said it's to much trouble to stay clean and not mess up the interior, not to mention the tight space to work in.
Any one out there had to deal with code#18 before?
Mike

[AFChap]

Originally Posted by mikee409

Paul, it's shaped like an upside down light bulb.

Found a local guy that had a code reader today. He could clear the past history codes but code #18 would not clear. It's labeled "fuel control valve"
I can't find this code on the "Cummins code section" on a google search.
Not sure how to proceed

My owner manual has 3 of that shape: One w/two little loops in it is "Wait to Start: Engine Preheat"; one w/ ! inside is "Engine fault warning"; one w/ STOP inside is "engine full stop." I suspect you are seeing the engine fault warning light. Of course, the next step is to read the codes, which you had done. The hardest part of RV service is most open finding a competent place who will do the work.

In the ISC codes list I found, there is none below 111. The only code ending in the digits 18 on that list is 418, which is the water in fuel circuit. I have had problems with that one, but it trips the water in fuel light ...a little gas pump w/ ! inside. I would think if there are problems with the fuel control valve you would have problems with it running, or even getting it started.

Good luck in finding someone who will work on it.

[dennis45]

Here is a list of codes. I don't see 18 though.

[mikee409]

I see the fmi 18 code it says low fuel delivery pressure. There is the same code for low oil psi also. I show good oil psi. I'm going with low fuel delivery pressure. Hope it's just a sensor and not the hi pressure fuel pump.
Problem is I don't know what to change first. Not even sure where the sensor is located.? Thanks for the code list

[slickest1]

I had that light come on on my 01 ISC 350. It did it a few times and I reset it by shutting it down and restarting. Finally it came on and stayed on and the shop I deal with read the codes and the one that came up was 134. Not real sure about that but anyway it said rear pumping element. Cummins had to do a little research and it wound up being the one solenoid on top of the Caps pump.
I am not saying that is the problem, it is probably something different but I would check with Cummins because it sounds like you may have a problem with your pump or something related. The Caps pump is not one of their best pumps. I had to replace the top end on mine and it cost $2500. Good luck!

[4Fingers]

Mike,
I would worry about fuel supply going to my CAPS high pressure injection pump. Do a search on CAPS failures. This is a very expensive repair. I have done a fix on all of my Cummins engine by installing a Fass aftermarket fuel system. This will provide positive pressure to your high pressure (HP) injection pump instead of it having to pull fuel all the way from your main fuel tank. Loss of fuel flow to the HP pump will ruin the pump. It will also allow you to filter the fuel properly to prevent nozzle clogging of the fuel injectors.
I installed the Fass systems on all of my trucks. It is not too hard to do if you can access the engine. On a motorhome everything is difficult to get too. I had a local diesel mechanic install my Fass system after I explained what I wanted. Cost me just over $1000, a lot less than $3000+ to replace the HP pump and not fix the cause. A lot of people get buy without the Fass fix, but now I have the peace of mind that I have done everything to prevent a future breakdown.

Happy Motoring
Don & Susan

[jimmy braden]

Always start with the basics/least expensive and work from there.

Since filters are fresh

Id go with a complete R&R of the lift pump and see if the code returns.


If you have to replace the CAPS pump then I would consider an aftermarket lift pump depending on miles.