ECM Issue

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ECM Issue

November 21, 2024, 06:27:43 pm

Finally received my Scanguage-D today and found 1 code (111 Engine Control Module Critical Internal Failure - Bad Intelligent Device or Component). It would appear that this code is cut and dry and that I need to replace the ECM. Are these more commonly repaired? I see ECM units online for Cummins ISC 8.3 at different price points (used of course). Some indicate a warranty (reman) and others do not. Are ALL ECM units for the Cummins 8.3 created equal or is there somewhere to identify part number and verify fitment based on engine serial number? I see some of these used ECM units online that came out of trucks, not diesel pushers.

Fortunately, if I need to send mine out somewhere for service, I just paid for another month where we have been staying. I read that the unit is located on the passenger side of the engine (since engine mounted backwards in DP), but after taking a quick look from the back, I could not see it.

What had been going on that started all this? Started with a check engine light that started flashing on and off real quick every so often. When that occured, it was accompanied by a very slight drop in power. (not enough to cause any problems driving) I replaced primary fuel filter and thought that was the issue. When we continued on it started doing this again. We made it to our destination and have been sitting for a while. Starting to get cooler in NV so I needed to fill the propane tank in the park. When I started the coach after about 10 seconds, the engine maint light came on, and 10 seconds beyond that a flashing stop engine light. I have never ever seen that light come on before. Strange thing is that after shutting the engine off immediately on the stop engine indicator, a restart appeared normal with no engine maint or stop engine. While engine was running all guages appeared to be where they should be and the engine sounded normal. So I guess with this ECM code revealed, that may explain the "gremlins" I have been experiencing.

Any advice would be greatly appreciated.

Dave

Re: ECM Issue

Reply #1 – November 21, 2024, 06:45:14 pm

Dave, call me before 8 pm central time. Rudy Legett. 7 one 3. 8 one 8. 3234

Re: ECM Issue

Reply #2 – November 21, 2024, 07:26:13 pm

If same place on my old 350 it is behind the fuel filter on engine. I was having issues with our coach at the time and ECM was removed and replaced only to have same issues. Turned out that cabling to it had been pushed around on fuel filter changes before we bought it and 2 of the many copper/brass connectors were cracked. Fixed them and all faults stopped. They only carry 4 or 5 volts so super sensitive.
Check wiring.
New one was $1400.00 but got refund as old one replaced.
Johnh

Re: ECM Issue

Reply #3 – November 21, 2024, 08:56:35 pm

Last winter my engine wouldn't start and I had ECM code and it turned out to be the heavy wire
to the ECM. A test light showed I had power and I should have used the test light I made using
a head light bulb and that would have showed I had a bad connection. I sent the ECM to
ECM King - Heavy Duty Truck ECM Rebuilders & Remanufacturers and they said it was fine.
They rebuild ECMs

Re: ECM Issue

Reply #4 – November 22, 2024, 10:25:34 am

Make sure the "low coolant" sensor wire is connected to the tank. Make sure wires to the injectors are intact. A bad injector wiring can damage the ECU.

Pierce

Re: ECM Issue

Reply #5 – November 29, 2024, 06:07:36 pm

Well ........ ECM King says they do not have the parts to repair the ISC ECM. I have taken a look at some of the other suggestions in this thread and all looks good. Strange thing is that the engine would start and sounds normal. Started every time. It also started without the warning lights in the dash every 2 or 3 times. Now, after 10 seconds it always shows the "engine maintenance" light and after another 10 seconds the flashing "stop engine" light. So it got progressively worse. The ONLY code on the ScanGuage-D is the Cummins ISC Fault Code 111 (26 times). No other codes. I know there are other code types that show the 111 error as a coolant sensor or something like that but that appears to only pertain to Cummins engines other than the ISC.

So I have the ECM out and was planning to send it off. Then I did some more checking. Called Scanguage and asked about my interpretation of the code the device displayed, I was told that the ScanGuage-D uses the codes listed at bigdieselcodes.com. So the 111 Cummins Fault Code would indicate an ECM issue, but that code is only meaningful if I am using a Cummins diagnostic product (like Insite). Am I right to think that?

Per bigdieselcodes.com, this is what the ID 111 / FM 01 my ScanGuage-D shows.

111 Engine Coolant Level 1 Ratio of volume of liquid found in engine cooling system to total cooling system volume. Typical monitoring location is in the coolant expansion tank.

FM stands for Failure Mode. The 01 is the ID. ID 01 is "Data valid but below normal operating range"

The coolant reservoir level is fine. What would cause the engine maintenance light to come on immediately followed by a stop engine light (on a cold engine)?

Will a bad sensor or malfunction tell the ECM to issue a Stop Engine?

The ECM may not be bad?

Suggestions?

Dave

Re: ECM Issue

Reply #6 – November 29, 2024, 06:55:31 pm

If it were me, I'd change the coolant sensor and see what happens.

Re: ECM Issue

Reply #7 – November 30, 2024, 06:09:10 am

The plastic sensor that cummins uses for coolant level cab leak internally and send coolant up the wires like a hose. Check the connectors for corrosion and replace the sensor if needed.

Re: ECM Issue

Reply #8 – November 30, 2024, 09:40:24 am

Call the guys at Truck ECM Computer Specialists | Repair and Programming

Re: ECM Issue

Reply #9 – December 01, 2024, 11:31:15 pm

Where is this sensor located on the 8.3?

Re: ECM Issue

Reply #10 – December 02, 2024, 12:43:13 am

If you are talking about the coolant level sensor. It's in the metal coolant tank next to the plastic reservoir.

Re: ECM Issue

Reply #11 – December 02, 2024, 12:52:29 am

That's what I thought Bruce. Thanks!

Re: ECM Issue

Reply #12 – December 02, 2024, 09:13:32 am

Could the coolant sensor be unplugged and a jumper installed to fool the ECM temporarily?

Re: ECM Issue

Reply #13 – December 23, 2024, 12:23:05 am

Update: If I knew I was going to full time in a coach someday, I would have been a diesel mechanic instead of a IT network engineer. It's amazing how you think you know what the issue is and it turns out to be nothing close to what you thought was going on. I almost sent out my ECM to a place in NC and halted that when I read the fine print on the order email that said "If the unit tests OK, we will rebuild it anyway". No thank you! I canceled the order on 11/29. They finally refunded my credit card on 12/20. I had to call Discover to dispute.

I learned that if not using (for example) Cummins Insite, that the 111 error code is NOT a bad ECM but a coolant sensor, the one on the black steel tank. I replaced it. Strange thing is that the black steel tank was empty! (So not really the sensor but replaced it anyway) The plastic reservoir to the right had coolant at the line for cold, so I never checked the black steel tank. In fact, I never opened that cap until the other day. I was told when I bought the coach to add coolant into the plastic tank.

So I am thinking then, where did the coolant go? The hose from the bottom of the radiator that goes to the engine looked "wet" on the engine side. That clamp was tightened up. That wasn't really the issue. The hose that goes from the steel tank to the plastic reservoir had a few leaks in it. When the system built up pressure coolant was dripping out of that hose. So I went to NAPA and got some new hose and clamps and replaced the old hose. So far it's good. I will be keeping an eye on the coolant in the black steel tank. I checked it yesterday morning and it was full.

Thanks to Bruce and everyone else who chimed in. Much appreciated.

Re: ECM Issue

Reply #14 – December 23, 2024, 08:57:37 am

Great outcome and update so others have that info for future searches!

That hose and also the one to the AquaHot overflow and in some cases the generator have been known to develop cracks at the fittings as they age. Coolant flows out from radiators or surge tanks when things are hot, but as they cool back down, instead of coolant being sucked back in, air is.

So check those hoses periodically and watch the overflow tank levels to make sure they change levels when systems are hot vs. cold.

Re: ECM Issue

Reply #15 – December 23, 2024, 09:53:27 am

Dave,

Michelle is spot on, as usual. Expanding on that advice a bit...

Following my armchair analysis of your "problem" and "solution", I believe you may still have another yet undiscovered coolant leak somewhere on your coach. You have done a great job following the clues and identifying symptoms of the coolant leak. First, the warning lights on your dash, which alerted you to an unhappy coolant sensor. When you replaced the sensor, you discovered that the black steel tank was empty. You are now trying to figure out where the lost coolant exited the system. You have replaced the hose that goes from the steel tank to the plastic reservoir. Good move, but I believe you should continue your investigation.

The simple diagram below illustrates the interaction between a radiator tank and a plastic expansion tank. On our coaches, the black steel coolant tank performs the same function as the top portion of a conventional radiator. It should be completely full of coolant at all times. The radiator cap on the steel tank includes a 2-way valve that allows coolant to flow back and forth between the steel tank and the plastic expansion tank. The rubber hose between the steel tank and the plastic tank will never be subject to any appreciable pressure (other than hydrostatic, which we can ignore). Coolant simply moves back and forth through the hose as the engine goes through heating and cooling cycles.

Since your black steel tank has probably been less than totally full for some time, you have likely not been seeing any liquid level change in the plastic expansion tank. As the level in the steel tank lowered, it would eventually get to the point where, when the engine was hot, it no longer expanded enough to reach the radiator cap. After that time, you would stop seeing changes in the plastic tank level. Since this would happen well before the steel tank was totally empty, you must be leaking coolant from some other point besides the hose between the steel tank and the plastic tank.

You have installed a new hose between steel tank and plastic tank, and you have filled the steel tank with coolant, and (I assume) filled the plastic tank to the "COLD" level line. It may take a number of engine heating/cooling cycles before the coolant level stabilizes. You might have some air pockets in the engine and cooling system that should gradually be eliminated. As this happens, the liquid quantity in the plastic expansion tank will go down, and must be replenished as required to maintain the proper "COLD" level.

I would suggest you remain vigilant and watch for coolant leaks everywhere under the coach. Up front under the area where the dash heater is located is one place. Around the water heater, if you have the "MotorAid" feature, is another. Coolant hoses run the entire length of the coach, and could leak at any point. After exercising your coach, anytime you park on dry clean concrete, check underneath for suspicious wet spots.

Good Luck!

Re: ECM Issue

Reply #16 – December 23, 2024, 10:20:01 am

Quote from: Chuck & Jeannie – December 23, 2024, 09:53:27 am

The radiator cap on the steel tank includes a 2-way valve that allows coolant to flow back and forth between the steel tank and the plastic expansion tank.

So Chuck jogged my brain with this to also suggest looking at the radiator caps as well, especially if they are original Aqua-Hot Maintenance "Fun"

Re: ECM Issue

Reply #17 – December 23, 2024, 10:59:35 am

Ours developed a leak at the black tank where the metal tube was soldered on the the neck of the cap. This allowed coolant to escape undetected. I brazed it back on again and no problem since.

Checking the oil before traveling should include the black tank sight glass and the air cleaner restriction gauge as well as a quick look at the belts. Just like preflighting an aircraft.

Pierce

Re: ECM Issue

Reply #18 – December 23, 2024, 01:04:00 pm

Dave, as spotless as your coach is,, I'm shocked that you had any kind of coolant hose issue / leak. Ive never seen any area of your coach that wasn't clean enough to eat off of. Shocked, just shocked.... Hey , glad it was a cheap fix. If not frustrating.

Re: ECM Issue

Reply #19 – December 23, 2024, 06:08:36 pm

As "clean" as it appears, looks can be deceiving on a 23 year old coach! I believe we are entering the "Gremlin" zone. I guess it's our turn. I just changed out the generator thermostat and am getting ready to test er out! Keeping fingers crossed.

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