MCI Field Notes

© Motor Coach Industries Int’l, Inc. and its subsidiaries. All Rights Reserved.
MCI Internal Field Note – 022
Reliability Alert
DDC GHG17 Engine Code 3216/16 SCR Inlet NOx Sensor
Affected Coaches:
•
All MCI MY17/18/19 DDC equipped Coaches with GHG17 engines.
Concern
• The cold weather has brought on a rash of engine codes for the DDC GHG17 engines in our J4500 Coach
model. Notably the 3216/16 - SCR Inlet NOx Sensor code. This code will cause a Maintenance Indicator Light (MIL) to
illuminate and can cause a derate of 25% of available power. In most cases the power derate will not be noticed. The
available power from the engine exceeds most operating environments. Some minor loss of performance on climbing
hills may be experienced.
Cause
• Exact cause is undetermined. Detroit Diesel has opened an engineering investigation along with MCI engineering to
determine root cause. It is estimated, this may take up to 3 months to solve. An interim solution is needed as a result.
Correction
• An interim solution has been developed by DDC that will temporarily suppress the 3216/16 code from illuminating the MIL
and avoiding the 25% derate. The on board experience will be transparent to the driver. This remedy will come in the
form of a need to apply a test calibration sticker on the engine and a new program uploaded to the engine. A DDC
technician is needed to complete. Widespread availability will be a couple of weeks in the process.
• There may be some time between getting the suppression program and test sticker applied. Operators should be in the
interim directed to continue their missions as long as they can maintain the posted speed limits. There is no progression
of this code to further derate the engine past 25%. In fact the derate will subside if the operating condition that activated it
is no longer present. Only the MIL will stay illuminated under this condition.
• In the case where you may need to remove the active MIL for code 3216/16, a SCR efficiency test can be applied and this
should clear the MIL as well as any derate that is in effect. This will need to be done by a qualified service technician with
a Pro Link type diagnostic tool. This can be recommended at the Operators convenience and is not necessary to continue
a mission.
Note
• Once an interim suppression program and sticker is applied, Virtual Technician (VT) will continue to broadcast 3216/16 email messages and the designated recipients will need to ignore in the interim. The intent of this is so the engineering
teams can still receive relevant field information from engines to supplement their ongoing investigation. Owners will need
to be clear on this point.
© Motor Coach Industries Int’l, Inc. and its subsidiaries. All Rights Reserved.
Nov 23, 2018