293-027

Mack Trucks, Inc.
Greensboro, NC USA
Date
Group
No.
Release
Page
1.2015
293
027
01
1(2)
EGR Mass Flow Rate Low
MP7, MP8, MP10 US2010
CHU, CXU, GU, LEU, MRU, TD
FSB 293-027, EGR Mass Flow Rate Low
(January 2015)
This bulletin is released to address high counts of diagnostic trouble code (DTC) SPN 2659
FMI 18 or P0401 only during normal to high load driving conditions on vehicles assembled
between January 2010 and December 2013.
It has been determined that deposits in the EGR cooler can build up and cause high
restriction over time. This high restriction prevents the required amount of EGR gas from
flowing through the EGR cooler creating DTC SPN 2659 FMI 18 or P0401 EGR Mass Flow
Rate Low to be logged intermittently. Normally, this is only reported on higher mileage
vehicles.
Note: This bulletin only applies to vehicles that are performing normally and only reporting
DTC SPN 2659 FMI 18 or P0401. If other EGR related codes or symptoms are reported,
follow the diagnostics in premium tech tool (PTT).
PV729-FSB293-027_M
USA69246
Mack Trucks, Inc.
Date
1.2015
Group
No.
Release
293
027
01
Actions required:
•
Use PTT to determine engine main software level and compare to applicable chart below.
If engine main software is equal to or greater than the applicable software levels shown in
the table below, no programming is required. If engine main software is below the levels
shown, engine ECM programming is required.
•
•
Replace the EGR cooler.
Clear inactive DTC after all repairs are completed.
Engine Main Software
Non-Integrated
Aftertreatment
Hydrocarbon Doser
Integrated Aftertreatment
Hydrocarbon Doser
Vehicles built from January
2010 to December 2012
22468503
22468510
Vehicles built from January
2013 to December 2013
Not Applicable
22396802
Note: Failure to update engine main software if required during a warrantable repair will result
in claim denial.
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