Recommend diagnostic tool to figure out why the Dash Warning Light on my 2002 Monaco Signature 40 is on?

[JJMonaco]

I need advice on how to read the error codes without going to the Cummins shop.  I thought I read some where that there was a way to have the dash warning light and the stop light blink out the error codes?   The coach has a Cummins ISM 500.  Do I need to purchase diagnostic or monitoring software -Silverleaf or Bluefire?

The warning light came on about a month ago and stays on when the engine is running.  I have not taken the coach out on the road  since this happened as I’ve been working on the leveling system and other issues.  There doesn’t seem to be an obvious problem the engine starts up fine and the transmission is working. I had been just starting up the coach in the driveway to air the system up and troubleshoot HWH issues.  Now the HWH system is repaired and its time to get the warning light figured out.  I checked all the fluid levels and the low coolant sensor- no problem there.  

 

 

[TomV48]

I have only a vague understanding of the very complicated systems of our coaches.  I'm not even sure but what I'm getting redundant information.  But on my cars I have an OBD scanner that reads all of the internal functions of the engine.  Next best thing I found for the diesel is a scan gauge.  And that puppy confuses me no end so I'm not even sure all of the things that it reads but if it reads any of the systems directly and your error light is an error, I suspect the scan gauge might read the correct data for you.

And when I'm not poking around trying to read internal functions, just rolling along, I keep the display set on RPM, engine temperature, current mileage, and cumulative mileage since the engine started.  Never bad to be able to look directly at those four items, if nothing else.

[BradHend]

To Retrieve Active Fault Codes:
1. Turn the ignition key OFF.
2. Turn the ignition key ON immediately apply three full throttle application. 3. Observe CHECK ENGINE and STOP ENGINE lamps.
a. If no active codes are recorded, both lamps will remain illuminated. b. If an active code is recorded, both lamps will illuminate momentarily, then flash the recorded fault.
c. When codes are retrieved, turn OFF the Engine Diagnostic switch.
The fault code will flash in the following sequence:
• The yellow CHECK ENGINE lamp will flash.
• There will be a short one to two second pause.
• The fault code will flash on the red STOP ENGINE lamp.
• There will be a short one to two second pause between each number. • When the number has finished flashing in STOP ENGINE, the CHECK ENGINE lamp will appear again. The fault code will repeat the sequence.
Each fault code will flash twice before advancing to the next code.

[Jdw12345]

Brad, 

  In step 2C, where is the Engine Diagnostic Switch, are you referring to the ignition switch?

[Yoaks5]

This is from my previous coach's owners manual. It was an 2004 navigator with an ISM. 

[jacwjames]

I have a Silverleaf VMSpc, it does display diagnostic codes but I cannot manually reset them using the system.  I believe if a problem is corrected the ECM will recognize this and the code will clear.

I had a code come up in 2021 when I was on a trip, something to do with fuel pressure.  I was in the process of fueling the rig but left the engine running, which I normally don't do, while I was standing at the pump I noticed the engine started to stumble, but cleared itself.  I jumped in the cab, no warning lights but I brought up the diagnostic screen on the Silverleaf and it was showing the fault code.  It has not come back.

Using the fault code I went to the Cummins Quickserve site and do some research on the code and found it was fuel pressure on the CAPS pump.  There is a sensor (s) on the caps pump and the ECM monitors the pressures and registers a fault if out of range. 

The Silverleaf is does monitor a bunch of parameters.  I will search for whatever the ECM provides information on and you can set up the screen however you want, fancy or plain.  I have a fairly simple display tracking oil pressure, engine & trans temps, voltage, speed, set cruise speed, turbo psi, and some other stuff.  On some of these I have alarms set.  I had been having trouble with high transmission temp after a radiator change (which I suspect the undersized the tranny cooler) and have added a auxiliary cooler, but I track the tranny temp and have even set up a data recorder so I can go back and see how the temps did during legs of a trip. 

I also set up a fuel minder that tracks consumption and based on how much I've used what is in the tank and miles to empty.  I zero this out when I fill up and it shows 128 gallons, my tank capacity.   I find this to be very accurate.  It will also track total miles on the trip.

The Silverleaf is not perfect but when I'm driving the coach doesn't move unless the Silverleaf is displaying all GOOD!

[Texomaman73]

I had my warning light come on about a year ago, after having it in storage for a couple months. Same thing happened to me, everything looked good and it ran same as always.  I did some research on here and found where people had same issue and never found what was causing it but they continued to use MH as normal.  I'm not a big fan of driving a vehicle with a warning light on but I needed to get the tires and I already had an appointment so I went anyway.  Drove it about 300 miles round trip to put some new tires on it and the warning light never went out.  It ran fine and without issue!                                                                                                                           

A couple months ago I was taking MH to Dallas for some repair work and when I got it back out of storage the warning light was still on however this time I brought it to my house and plugged electrical in at house so I could have heat overnight before going to Dallas the next morning.  Woke up and started MH and warning light was gone.  Took coach to Dallas had repairs done and picked it up and drove it back home 350 miles total and warning light never came on again.  

I believe that the batteries were low and it being plugged in overnight charged them to a level that was acceptable. 

This may not be your issue but it doesn't cost anything but a little time to check.

[Gary 05 AMB DST]

Look up DieselServiceParts.com for the codes.

Gary 05 AMB DST

[JJMonaco]

To update on my warning light issue- Thanks to all for the suggestions on diagnosing the warning light and its error code, software, etc.

I took my coach out for a test drive after my last post.  It had not been on the road for several months. I had hoped the warning light would go away after driving a bit.  It did not.  I found I had a big-time loss of power.  I could barely get the speed up to 50 mph.  Boost pressure would not go higher than 6 on the gauge.  The cruise control does work.  From my understanding, the ECM must have depowered the ISM 500 due to the error code.  The jake brake doesn't work and I think this happens when the ECM depowers the engine.

It turned out that Yoats5 - Keven Y had the solution for how to read the error code on my ISM 500. Thank You!

I found the shorting plug under the dash above my left foot and followed the direction in the info he posted.  Basically, when the shorting plug is connected and you turn on the key without starting the engine, if the warning light and the stop engine light on the dash stay on, the warning light will start flashing out the error code.  Like most things, it's pretty simple to do once you have the directions.  The error code was #123.  It means low pressure is being read at the intake manifold. 

The first thing I thought to check was the air filter. I live here in Florida a little North of Ft. Myers.  We had gone through Hurricane IAN with 130 mph winds and our home had roof damage from fallen trees and lots of flying debris. The coach was parked outside my home facing into the wind.  I checked the air filter gauge in the engine compartment that is supposed to tell you when it's time to change the filter. It showed it was OK after my first test drive.  Next, I took the filter off to check it.  Sure enough, it had caught lots of leaf particles and debris inside. 

I installed a new air filter today and took the coach out for another test ride.  The warning light disappeared after about three miles.  However, after driving it for about 30 minutes on the highway I still have a significant loss of power and no jake brake.  With the pedal to the metal, acceleration is very slow, the rpm will get up to 2000 rpm when it shifts.  Speed wise it will only get up to a little over 60 mph max.  Boost pressure is a max of 7.5. The cruise control does work.  I don't have any warning lights.  When I got home I checked for error codes again using the shorting plug procedure.  There are no error codes.  I did stop along the test drive and shut off the engine and let the coach sit for a couple of minutes, before restarting and going on my way, thinking it would reset the ECM.  I thought the ECM was supposed to automatically reset.  Is there something I'm missing, or is there a way I can manually reset the ECM?  Do I have another issue?

Time for a new post on that question.

Thank You,

JJ

[jacwjames]

On my coach there is an accordion type air intake hose coming from the intake box to the air filter, did you check to see if there are any obstructions in the whole air intake system??  My system has a box with a duck bill drain at the bottom.  If you had a lot of debris in the air intake it could have gotten a lot of water in it. 

[cbr046]

I'm thinking along those same lines . . . an issue in the intake / exhaust / turbo tract keeping boost from building.  Maybe take the hatch off and listen / look for air leaks.

Just guessing, tho

- bob

 

[JJMonaco]

Jim & Bob-Thanks for the ideas. I know the large plastic corrugated intake hose was clear when looking into it from the filter intake side. I did not notice any moisture in the pipe or the old filter. The particulate in the old filter was dry.   Tomorrow I will try to get into the rest of the air intake system and see what that looks like.  I would think since the warning light and error code are gone that there isn't an air restriction anymore.  I wish I had a good code reader!  It feels like the ECM is still depowering the engine.

[jacwjames]

Easiest thing to do would be to remove the hose going into the filter and see if it helps.

When was the last time you changed your fuel filters?

[JJMonaco]

I changed them last April.  They only have about 3500 miles on them.  I have never drained any water out of the secondary, so I will check that...

Tnx.

[Frank McElroy]

10 hours ago, jjroxus said:

To update on my warning light issue- Thanks to all for the suggestions on diagnosing the warning light and its error code, software, etc.

I took my coach out for a test drive after my last post.  It had not been on the road for several months. I had hoped the warning light would go away after driving a bit.  It did not.  I found I had a big-time loss of power.  I could barely get the speed up to 50 mph.  Boost pressure would not go higher than 6 on the gauge.  The cruise control does work.  From my understanding, the ECM must have depowered the ISM 500 due to the error code.  The jake brake doesn't work and I think this happens when the ECM depowers the engine.

It turned out that Yoats5 - Keven Y had the solution for how to read the error code on my ISM 500. Thank You!

I found the shorting plug under the dash above my left foot and followed the direction in the info he posted.  Basically, when the shorting plug is connected and you turn on the key without starting the engine, if the warning light and the stop engine light on the dash stay on, the warning light will start flashing out the error code.  Like most things, it's pretty simple to do once you have the directions.  The error code was #123.  It means low pressure is being read at the intake manifold. 

The first thing I thought to check was the air filter. I live here in Florida a little North of Ft. Myers.  We had gone through Hurricane IAN with 130 mph winds and our home had roof damage from fallen trees and lots of flying debris. The coach was parked outside my home facing into the wind.  I checked the air filter gauge in the engine compartment that is supposed to tell you when it's time to change the filter. It showed it was OK after my first test drive.  Next, I took the filter off to check it.  Sure enough, it had caught lots of leaf particles and debris inside. 

I installed a new air filter today and took the coach out for another test ride.  The warning light disappeared after about three miles.  However, after driving it for about 30 minutes on the highway I still have a significant loss of power and no jake brake.  With the pedal to the metal, acceleration is very slow, the rpm will get up to 2000 rpm when it shifts.  Speed wise it will only get up to a little over 60 mph max.  Boost pressure is a max of 7.5. The cruise control does work.  I don't have any warning lights.  When I got home I checked for error codes again using the shorting plug procedure.  There are no error codes.  I did stop along the test drive and shut off the engine and let the coach sit for a couple of minutes, before restarting and going on my way, thinking it would reset the ECM.  I thought the ECM was supposed to automatically reset.  Is there something I'm missing, or is there a way I can manually reset the ECM?  Do I have another issue?

Time for a new post on that question.

Thank You,

JJ

Since you went through a hurricane take a close look at the charge air cooler for any damage.  Since you now aren't seeing trouble codes, low boost pressure is either a air filter restriction, a large air leak after the turbo, a turbo actuator not properly working, or possibly clogged fuel filters.

[JJMonaco]

Frank,

I'm not sure what and where the charge air cooler is and how to check it.  Can I assume it is in line after the air filter?

[Frank McElroy]

51 minutes ago, jjroxus said:

Frank,

I'm not sure what and where the charge air cooler is and how to check it.  Can I assume it is in line after the air filter?

The charge air cooler is between the turbo and the intake manifold.  It would be on the radiator stack with two large air hoses connected to it.  It's purpose is to cool the hot compressed air before it enters the intake manifold.

[cbr046]

1 hour ago, jjroxus said:

Frank,

I'm not sure what and where the charge air cooler is and how to check it.  Can I assume it is in line after the air filter?

It's the big "radiator" in the air intake system.  It cools the compressed air.  Here's a conceptual drawing:

http://cdn.detroitmanuals.info/cummins/images/4310591/10100052.png

- bob

[Jdw12345]

In this picture you see the AC condenser up top,

the transmission cooler below the condenser 

and the CAC directly behind those two coolers and behind the CAC is the radiator for the engine coolant.

on the right and left sides you can see the duct work coming from the turbo and going to the intake manifold.

  Hopefully this helps you identify the parts of the system.

 The picture might not be your exact configuration but the parts are basically the same.

 

Edited February 16, 2023 by Jdw12345

[bic237]

I have had the same light problem for years. Spent bunch of money, they did nothing, still have problem.  Also did extra scanner thing too, no results.  On Jake brake problem, mine did same thing and after driving and watching brake function (sure is hard to run back and forth!) we discovered the shaft on brake was not retracting completely which caused the low speed and boost troubles. I ordered some lube from the brake company and applied to the points shown on bottle and forced shaft out as far as I could, inch or two, lubed shaft heavily.  Drove it, worked like new, boost back also!

  Occasionally my light would go out for a short time, after doing lube the light did not come on. I'm not saying it fixed the light but it did fix jake brake and related no turbo boost.

[Yoaks5]

My 04 navigator with the ISM in it had a power loss when I bought it. I tried every thing I could to find out the issue. There was no warning light. I finally took it to Cummins in des moines and they diagnosed a bad injector. They didn't have one so I brought it home and ordered one from a local mack truck dealer and installed it. Took it on a drive and it had great power. Drove it for about 30 minutes but before I got back home I lost power again. I thought either the new injector was bad or another injector had gone bad. So I took the valve cover off and started the motor and carefully unplugged the injectors one at a time to see if it would make any difference in the way it was idling. Every one I unplugged made it run ruff, so that led me to believe that it was not a bad injector this time.

Once again I couldn't figure out what it was so I took it back to Cummins and they diagnosed the Turbo actuator was bad. They fixed that and it ran good the rest of the time I owned the coach. 

I'd check your turbo actuator 1st since your not getting much boost. 

It's been a couple years ago so my memory is foggy but I think I had good boost when the injector was bad. 

[Bruce S]

We once had a severe loss of power issue where we blew a turbo boot.  Coach would accelerate on a level or downslope but uphill it dropped down to 10mph.  There are several boots and any one of them can cause you grief.  There were no warnings on the dash and while parked and idling no noise was heard... but there was a loud bang when the boot blew...

[timaz996]

I agree with a few here as it is a leak in your boost system plumbing. (CAC, Boots). If you have a pyranometer the Exhaust temp will be real high with low boost because of the leak. Have someone pressure test your pressure side.

Tim 

[JJMonaco]

7 hours ago, Yoaks5 said:

My 04 navigator with the ISM in it had a power loss when I bought it. I tried every thing I could to find out the issue. There was no warning light. I finally took it to Cummins in des moines and they diagnosed a bad injector. They didn't have one so I brought it home and ordered one from a local mack truck dealer and installed it. Took it on a drive and it had great power. Drove it for about 30 minutes but before I got back home I lost power again. I thought either the new injector was bad or another injector had gone bad. So I took the valve cover off and started the motor and carefully unplugged the injectors one at a time to see if it would make any difference in the way it was idling. Every one I unplugged made it run ruff, so that led me to believe that it was not a bad injector this time.

Once again I couldn't figure out what it was so I took it back to Cummins and they diagnosed the Turbo actuator was bad. They fixed that and it ran good the rest of the time I owned the coach. 

I'd check your turbo actuator 1st since your not getting much boost. 

It's been a couple years ago so my memory is foggy but I think I had good boost when the injector was bad. 

How would I go about testing the turbo actuator?

[jacwjames]

Do you have a Cummins Quickserve account. 

There are maintenance manuals on line that you can access.  I had downloaded the ones for my 8.3 ISC several years ago, I checked and there is a complete section on how to test the actuator.