Reading Fault Codes on Cummins ISB Engine

rsalhus · 07-06-2011, 04:42 PM

I had a yellow Engine Fault light come on and off while idling and also while driving a few miles. While idling, the engine would act like it was going to kill, catch itself, and idle higher for a bit before returning to normal idle. While it was doing this, the yellow Engine Fault light would flicker and the light would come on and off. After driving it awhile (after it got warmed up?) it acted normal and the yellow Engine Fault light remained off the rest of the trip.

I'm wondering if the ECM might have thrown a fault code when this happened. I have a push button below the display panel that I think is related to reading fault codes, but so far I haven't figured out how to use it. A call to Spartan Chassis didn't help and the guy there thought that it wasn't possible to read the fault codes on this coach. Anyone know how to read the fault codes on this engine (the coach is a 2001 Rexhall Vision, Cummins ISB, 5.9L, 260 HP)?

srydve · 07-06-2011, 05:45 PM

I can't say for sure but I doubt you can read the codes without an external reader. I purchsed the VMSpc for that purpose for my 5.9. If you could find someone who has the system hooked to a laptop they might be willing to read your codes for you, I'm sure the fault will be there. Failing that I think you are stuck with a repair facility.

KIX · 07-06-2011, 05:58 PM

I believe Srydve is correct.
Excessive idling may cause the MIL to illuminate. On an ISC engine excessive idling is considered to be more than 5 minutes. Your post mentioned that you drove the coach "after I got it warmed up". If you are trying to warm up your engine by idling you are probably excessively idling.

rsalhus · 07-06-2011, 05:59 PM

Quote:

Originally Posted by srydve

I can't say for sure but I doubt you can read the codes without an external reader.

I read somewhere that I might be able to read the fault codes by turning on the ignition key and pushing the accelerator pedal to the floor 3 times in 5 seconds.

You are supposed to see a red and yellow light on solid for a few seconds, then the yellow light will flash three numbers with a pause in between each. I tried this and all I got was the solid red and yellow lights on with no flashing lights after. This could mean that there is no active fault code I think. Apparently, only active codes can be read this way and maybe I have no active code since the yellow Engine Fault light is not currently lit. Not sure if this is right or not.

rsalhus · 07-06-2011, 06:10 PM

Quote:

Originally Posted by KIX

I believe Srydve is correct.
Excessive idling may cause the MIL to illuminate. On an ISC engine excessive idling is considered to be more than 5 minutes. Your post mentioned that you drove the coach "after I got it warmed up". If you are trying to warm up your engine by idling you are probably excessively idling.

No, I am not excessively idling it. I meant to say that the light went off for good after it had warmed up, and I was questioning whether that was the reason the light went off (because it had warmed up). BTW what is MIL?

KIX · 07-06-2011, 06:17 PM

Quote:

Originally Posted by rsalhus

No, I am not excessively idling it. I meant to say that the light went off for good after it had warmed up, and I was questioning whether that was the reason the light went off (because it had warmed up). BTW what is MIL?

Automotive jargon for Malfunction Indicator Light

The only other thing I can think of is the air filter.....if it's restricting air flow it may be enough to activate the MIL at idle. With the increased air flow "at speed" it may not be restricting enough to activate the MIL. I guessing but if it were me that's what I would look at.

rsalhus · 07-06-2011, 06:32 PM

Quote:

Originally Posted by KIX

Automotive jargon for Malfunction Indicator Light

The only other thing I can think of is the air filter.....if it's restricting air flow it may be enough to activate the MIL at idle. With the increased air flow "at speed" it may not be restricting enough to activate the MIL. I guessing but if it were me that's what I would look at.

That makes sense, but the air filter has less than 10K miles on it and less than 2 years since I changed it myself. And the filter gauge shows the filter is clean.

KIX · 07-06-2011, 06:47 PM

ok......I'm out of guesses.
If you had a VMSpc as available from Silverleaf Electronics (Google them) you may be able to diagnose this issue and future issues too.

Triker56 · 07-06-2011, 06:48 PM

You need to have a VMSpc it will store any faults.

PandK · 07-06-2011, 06:52 PM

My coach has three rocker switches mounted near the drivers left foot. Mine was actually behind a carpeted panel the coach mfg had installed. On of the switches is labeled engine diagnostics. If I push that it will flash the stored engine faults.
Sorry I can not offer any additional info as I was on the phone with Spartan last week (different issue) and asked about the switches and that was the answer I got. Not sure if the switches are Spartan specific or not. I called 800 543 4277

With the proper adapter and the Cummins PowerSpec software you can also read any stored codes.

greystroke · 07-06-2011, 07:02 PM

I have a VMSpc that I run on a 10 inch netbook. As you drive the codes will be automatically stored. You can also display the diagnostic window while you drive to watch the codes occur so you can relate it to what the engine is doing real time.

The display gives an SPN and FMI codes and a general exp of the problem.

You can use these codes to convert to a Cummings fault code and then you can go to Cummins procedures for analysis and repair.

I built an excel file to serve as the crossreference to Cummins codes.

Would not leave home without it.

rsalhus · 07-06-2011, 07:13 PM

I've been looking at the VMSpc for quite awhile now. I'm just having a tough time justifying the cost and wondering where I would put the laptop and how I would power it while on the road. It seems like I'm the only motorhome owner left that doesn't have one. (Now if I can only convince my wife of that............)

KIX · 07-06-2011, 07:16 PM

You can get an inverter that plugs into cigarette lighter socket that would be able to power a laptop while you're driving.
Convincing your CFO is your job.

rsalhus · 07-06-2011, 07:18 PM

Quote:

Originally Posted by PandK

My coach has three rocker switches mounted near the drivers left foot. Mine was actually behind a carpeted panel the coach mfg had installed. On of the switches is labeled engine diagnostics. If I push that it will flash the stored engine faults.

What kind of coach do you have? I would guess that one of the switches would be for the transmission? Couldn't guess about the third.