DD15 - SPN 100 FMI 1 - Engine Oil...

Jim Langeveld 8 posts since Feb 22, 2019
DD15 - SPN 100 FMI 1 - Engine Oil Pressure Too Low Oct 26, 2020 8:59 PM
We have unit JZ8522 with an intermittent issue throwing a SPN 100 FMI 1.
The driver is reporting that each time it comes on the engine is coming out of coast mode and beginning to find
a gear. The Check/Stop engine flash but then no further issues persist. It happens once or twice a month and
not persistent enough to log. I have attached the Detroit Connect data but nothing there points to anything that
could cause a problem.
Completed troubleshooting for this code and no issues present itself at this time. All software levels have been
updated to the latest and greatest.
I am wondering if anyone else has had the same issue?
• Detroit Connect - Portal.pdf 2.9 MB Preview

Jon Cecil 852 posts since Nov 25, 2014
Re: DD15 - SPN 100 FMI 1 - Engine Oil Pressure Too Low Oct 27, 2020 1:10 PM
Have you hooked up a manual gauge and compared to the oil pressure sensor and gauge?
Any repair history in the lower end?
Possible spread pin or short for the oil pressure sensor. I would disconnect the 120 MCM pin and the oil
pressure sensor to inspect. If no issues are found, load test the circuits. It might be worth while to install a new
oil pressure sensor to see if the issue gets corrected.
Aerated oil can cause intermittent oil pressure issues. Usually the o rings on the pickup tubes but I have yet to
see this in a GHG17 engine.

Jim Langeveld 8 posts since Feb 22, 2019
Re: DD15 - SPN 100 FMI 1 - Engine Oil Pressure Too Low Oct 28, 2020 3:44 PM
Thank you Jon for your input. We have confirmed wiring and sensor bias is not the issue. The problem is that
it happens so infrequently, and never near the shop, It happens for a fraction of a second and about once per
month. Its one of those nuisances that bring up such a serious code and you would like to fix but have a hard
time pinning it down. We don't want to find out later that it was something that should have been addressed a
lot earlier. Next time we drain the oil we will check O-rings on pickup tubes

Pat Moran 103 posts since Nov 30, 2015

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DD15 - SPN 100 FMI 1 - Engine Oil...

Re: DD15 - SPN 100 FMI 1 - Engine Oil Pressure Too Low Oct 28, 2020 4:44 PM
Jon had some great suggestions in his post. Sounds like you have diagnosed the sensors and qualified that
side as good.
The last line in Jon's post talks about possible issues with oil pump O-rings. There was an issue with DD
engines built prior to 2013 with suction tube O-rings that would get hard and suck air. The fix is described
in 15TS2 attached below. I agree with Jon that this engine is above the break point for that issue, but your
description of the failure mode sounds very similar to what we saw with the o-ring issue. Hot engine, truck
comes to a stop and shows the 100-1 code for just a moment or two. Looking at the log file you attached, you
can see where the code sets during ECoast. One thing to note is that ECoast drops the engine RPM to 500,
the lowest it would ever see. That is a probable explanation for why it sets the code at that point
I would inspect O-rings, oil pump, oil manifold and all seals in the basement related to the oil pump. One of
the VT logfiles show the mileage on this truck at 517,000 miles. Certainly a chance for old and battle hardened
seals at that mileage
In the 100-1 troubleshooting, they also describe looking at the oil filter bypass valve and the oil filter drain
valve in the bottom of the housing. Both of those deserve some close inspection.
• 15TS2.pdf 128.5 KB Preview

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