NON-COMPLIANCE RECALL
Mack Trucks Inc.
Greensboro, NC USA
Date
09.2024

Number
EC0033

Release
02

Page
1(6)

M0311 SCR Replacement, MP8 TC Engine
AN, CHU, and PI
RECALL INFORMATION

Revised 10/25/2024 Gasket 22677399 Changed to 21376801
(September 2024)
Mack Trucks has identified that the Selective Catalyst Reduction (SCR) system in certain vehicles
equipped with the MY 2017 or 2018 MP8 Turbo Compound (TC) engines are not meeting California and
EPA emissions standards, or Mack cannot confirm its compliance. These vehicles have been flagged
due to telematics data showing that the NOx conversion efficiency of the SCR system has dropped
below 94% for eight weeks. Alternatively, these vehicles may have communication issues with
telematics, such as not reporting or ceasing reporting for the same period.
To ensure Mack remains emission compliant on these vehicles, follow the repair instructions outlined in
this document to replace the Selective Catalyst Reduction (SCR) system with new one.

VEHICLES AFFECTED
Certain Mack vehicles manufactured between January 24, 2017, and January 28, 2019.

VEHICLE QUANTITY
This Vin list will be dynamic, VIN’s will be added to the VIN list in 8-week cycles based on monitoring
from Recall M0304.

Mack Truck Inc.
NON-COMPLIANCE RECALL

Date 09.2024

Page 2 of 6

Parts Information
The SCR Muffler should be ordered VOR, all other parts should be ordered through normal process.
Part Number
23160669
23108406
21376801
990413
21095726
21095721

Description
SCR Muffler
Clamping band kit
Gasket
Screw
Gasket
Gasket

Quantity
1
1
1
3
3
1

Important Parts Note!
Please dispose of the SCR Muffler following the normal process.
Repair Instructions
Important Service Note!
Before replacing the SCR Muffler under this recall, you must verify that M0304 Software Recall
has been completed. If M0304 Software Recall has not been completed, it must be done first.
1.
2.
3.
4.

Park the vehicle on a level surface.
Apply the parking brake.
Place the gear lever in neutral.
Install wheel chocks.

5. Follow Impact operation 2586-03-02-10 Muffler, Replacement (Combined DOC, DPF,
SCR) Decontented to replace the SCR with a new SCR muffler.
6. Install and fill out the Campaign Completion Label if needed.
7. Remove the wheel chocks.

Mack Truck Inc.
NON-COMPLIANCE RECALL

8. Release truck to customer.

Date 09.2024

Page 3 of 6

Mack Truck Inc.
NON-COMPLIANCE RECALL

Date 09.2024

Label & Certificate Instructions
NOTE

Page 4 of 6

Mack Truck Inc.
NON-COMPLIANCE RECALL

Date 09.2024

Page 5 of 6

Important Note!
If needed, print out this Emission Recall Proof of Correction Certificate. Fill in the appropriate information
for your records and provide a copy to the customer.

Mack Truck Inc.
NON-COMPLIANCE RECALL

Date 09.2024

Page 6 of 6

REIMBURSEMENT

This repair is covered by an authorized Non-Compliance recall. Reimbursement is obtained through the
normal claim handling process.

UCHP
Reimbursement
Claim Type (used only when uploading from the Dealer Business
System)

40

Recall Status
Vehicle repaired per instructions

1-Modified per
instructions

Labor code

2586-03-02-10 Muffler, Replacement (Combined DOC, DPF, SCR)
Decontented

Use
Impact

Causal Part

21970120
Authorization Number

M0311

Note: Dealers are to perform Non-Compliance Recall on all subject vehicles at no charge
to the vehicle owner regardless of mileage, age of vehicle or ownership (original purchaser
or subsequent purchasers). Whenever vehicles are subject to a Non-Compliance Recall are
brought to your dealership for service, or taken into your dealership vehicle inventory, it is
strongly recommended that every effort be made to perform the recall correction before the
vehicle is sold or released to the owner.