Solution K21052070
Thursday, July 5, 2018 4:21:45 PM CEST

Mack Models
Mack Model

LR , MRU , Anthem , CHU , CXU , GU

Volvo Models
Volvo Model

VNR , VNX , VNL , VNM , VHD , VAH

Engine family
Engine family

11L Engine , 13L Engine , MP7 , MP8

Emission Standard
Emission Standard

2018 , OBD2017

** SOLUTION **
Title

Intermittent Occurrences Of Very Brief Loss Of Power, Engine Stumble Or Hiccup
Lasting Much Less Than A Second, Most Frequently Between 1500 And 1700 RPM, No
Diagnostic Trouble Codes ( DTC ) Generated - All Common Rail Fuel System Chassis US17+OBD16 And Newer Emissions, Commonly Model Year 2018 And Newer

Cause

In Common Rail Fuel System engines, engine power may be lost for a very brief period
of time, (less then 0.5 seconds), before recovering and behaving normally. Descriptions
of the issue may include symptoms such as loss of throttle, loss of power, or engine
stumble or hiccup. Symptoms will most often be observed between 1500 and 1700 RPM
and at lower engine load, although engine loads may vary. Frequency of occurrence
may be approximately once every 25 miles (40 km) to once every 2-3 miles (3-5 km),
depending on operating conditions. There will be no Diagnostic Trouble Codes (DTC)
associated with symptoms.
For trucks equipped with an Automated Manual Transmission (AMT), the Gear Shift
Display may briefly flash a lower gear number when other symptoms occur.

Solution

Verify the chassis emissions level and ensure that the vehicle is within the
applicable range for this solution.
- Details can be found in the Product Details box on the Product tab in PTT as seen
below:

Software improvements have been released to address this issue.

1. Check the Main Software (MSW) part number of the Engine Control
Module (EMS)
A. If the MSW part number is lower than 23398790
1. Update the EMS software
2. Release the chassis after verifying there are no other issues.
B. If the MSW part number is 23398790 or above
1. DO NOT PERFORM DIAGNOSTICS IF THIS ISSUE IS PRESENT AS
DESCRIBED ABOVE WITH NO ACCOMPANYING CODES OR OTHER
SYMPTOMS
2. An eService case is required for all GHG17 vehicles and should be opened for
a shop visit with repairs involved.
3. The eService case MUST INCLUDE:
a. A complete description of the customer report with all symptoms noted by
both the customer report and the technician.
b. A complete DTC readout from the time of the truck's arrival.
c. A thorough description of any repair history that could potentially be
related to this issue (EGR, turbo, VGT, fuel system, exhaust blockage, etc.)
- "Truck has been in for this previously" with no other details does not
provide any information for review.
d. If any diagnostic work was performed prior to the case, all test performed
with numerical values of the results should be provided.
- "Performed GD", "Checked system", "Okay", "Good" are not
acceptable descriptions and values for work performed.
Temporary solution

Temporary solution

Function(s)/component(s) affected
Function affected

engine , regulation (cruise control/engine speed) , 1 1 0 EMS

Function Group
Function Group

28 ignition and control system

Customer effect
Main customer effect

stumble , engine speed , efficiency/abnormal behavior , power , loss of drive

Acceleration/speed

throttle

Road behaviour

driveability

Conditions
Vehicle operating mode
Frequency of occurrence of
problem
Engine speed

when driving
random
1500 - 2000 rpm

Road conditions

flat road

Administration
Author

UT5061H

Dealer ID

UT5061H

Last modified by

RU4469V

Creation date

24-04-2018 14:04

Date of last update

29-06-2018 18:06

Review date

01-01-2019 00:01

Status

Published

NA_Reviewer

UT5061H