No.: 21TS-12
August 2021
TO:

Service Locations

FROM:

Service Systems Engineering

SUBJECT:

GHG21 Detroit DD16® Poor Acceleration Complaints In Western Star
49X Chassis When Lightly Loaded

ISSUE
Some complaints have been received about poor acceleration with the DD16 engine in the
Western Star 49X chassis when the vehicle is unloaded or lightly loaded.
CAUSE
Corrections have been made to the CPC software to resolve this issue. Truck plant
implementation began on August 5, 2021, and should be complete on September 5, 2021.
For trucks built before September 5, 2021, the server was updated on July 28, 2021, so any
DD16 in a 49X that has the CPC programmed should be fixed.
REQUIRED ACTION
Program the CPC. After programming the CPC, the MCM, ACM, and TCM (if equipped with a
Detroit DT12™ transmission) may need to be updated for software compatibility.
REPAIR PROCEDURE
Note that the current version of reprogramming software is DiagnosticLink® 8.14 with Service
Pack 2. Program using “Update Device Software”.
1. Connect DiagnosticLink® to the MCM, ACM, CPC, and TCM (if equipped with a Detroit
DT12™ transmission), and note the current software and fuel maps in the Identification
screen.
2. Program the CPC to R20.31.00.00A software (or higher). If equipped with a Detroit DT12™
transmission, the shift map should be p/n A0264488202 ZGS 002. Note this may be the
same software and shift map already in the CPC – the necessary changes will not be
visible.
3. If not already there, program the ACM to 7.61.1.0 software (or higher) with fuel map p/n
A0304482754 ZGS 001.
4. If not already there, program the MCM to 6.9.0.2 software (or higher) with fuel map version
ZGS 003.
5. If not already there for Detroit DT12™ equipped vehicles, program the TCM to
NAMT201403 software (or higher).
6. Disconnect the USB Link at the vehicle diagnostic port.
7. Turn the vehicle ignition OFF and wait one minute.
8. Turn the vehicle ignition ON and wait one minute.
9. Turn the vehicle ignition OFF and wait one minute.

Detroit Diesel 13400 Outer Drive, West / Detroit, Michigan 48239-4001

21TS-12

-2-

8/20/2021

10. Turn the vehicle ignition ON and wait one minute.
11. Reconnect the USB Link, reconnect DiagnosticLink to the MCM, ACM, CPC, and TCM (if
equipped with a Detroit DT12™), and confirm software and fuel maps in the Identification
screen.
12. Check to see if Auto Elevate is enabled. If not, reference Detroit Technical Service letter 16
TS-18 to see if it can be enabled. To turn on Auto Elevate, go to the ACM parameters,
group PGR005_DPF, item "Extended Idle Auto RPM Elevate", value is “1 enabled”.
CLAIM PROCESS
Normal in-warranty procedures apply. If a CPC software failure is found, file the claim as
follows:
• Claim type: 1 (base warranty) or 2 (extended coverage)
• Fault type: 95
• PFP: RPCPC
Possible labor operations are shown below:
• 3RD-6901E Reprogram One Module, MCM, CPC, or ACM
• 3RD-6911E Reprogram Two Modules, MCM, CPC or ACM
• 3RD-6915E Reprogram Three Modules, MCM, CPC and ACM
• 3RD-6916E Reprogram Four Modules, MCM, CPC, ACM and TCM
• Admin Labor Operation 939-6010B
CONTACT INFORMATION
Please contact the Detroit Diesel Customer Support Center at 800-445-1980 or email
[email protected] if you have any questions.