K15560422

Solution K15560422
Thursday, May 3, 2018 7:32:06 PM CEST
NA_MACK_Vehicle_Range
NA_MACK_Vehicle_Ran
ge
Cabover , Conventional
NA_VOLVO_Vehicle_Range
NA_VOLVO_Vehicle_Ra
nge
VNR , VNX , VNL , VNM , VHD , VAH
Engine family
Engine family
11L Engine , 13L Engine , 16L Engine , Mack , MP7 , MP8 , MP10
Emission Standard
Emission Standard
2018 , OBD2017 , US17 GHG , US16 , US15 , US13 OBD , US14 GHG
** SOLUTION **
Title (customer effect)
Selective Catalytic Reduction ( SCR ) Efficiency And NOx Sensor Codes P225C,
P225E, P221A, P2201, P103C, P20EE, And P207F : NOx Sensor Diagnostic
Information TO BE USED BEFORE SENSOR REPLACEMENT - OBD13 And Newer
Emissions (Commonly Model Year 2014 And Newer)
Cause
Diagnostics for codes related to SCR efficiency and NOx sensors may lead to
replacement of NOx sensors that are functioning properly.
Solution
DO NOT REPLACE EITHER NOx SENSOR FOR ANY OF
THE ABOVE CODES PRIOR TO REVIEWING THE
INSTRUCTIONS BELOW
The purpose of this article is to prevent unnecessary component replacement. ALL
OTHER DIAGNOSTIC TESTS AND CHECKS MUST BE PERFORMED when
diagnosing one of the codes above if the tests below do not immediately reveal an
issue.
If an eService case must be submitted, ALL INFORMATION specified in Step
Five MUST be included at the time the case is opened. Cases missing required
information will be Refused.
Overview
Guided Diagnostics for SCR efficiency or NOx sensor fault codes will often result in No Fault
Found. This often leads to replacement of one or both sensors despite no indication from
diagnostic steps to do so. NOx sensor function is a possible cause, and is listed as such for the
code description in the DTC description in Premium Tech Tool ( PTT ). However although the
sensors themselves are a possibility, NOx sensor codes are most often a symptom, not a
cause of emissions issues. NOx sensors should be confirmed to be reading incorrectly or
functioning erratically before they are replaced.
Fault Codes
A complete list of DTCs related to this Solution can be found in the Fault Codes section below.
Procedure
- Review the Detailed Status Information for the relevant code on the DTC Readout.
• If Confirmed DTC is TRUE: Proceed with diagnostics
• If Confirmed DTC is FALSE: Disregard and focus on other symptoms or DTCs relevant
to the complaint.
- A NOx Conversion should be run to check NOx sensor signal and function for any of
the above codes.
NOTE: A NOx conversion test only checks NOx sensor function. The test compares the
readings of the two sensors as the engine cycles through multiple conditions to confirm they
are in agreement. The results of the NOx Conversion test do not indicate anything about
the condition of the SCR itself.
1. In PTT, run Operation 2549-08-03-03 NOx Conversion, located under the Test tab.
2. Take screenshots of the graph and sensor values approximately 2-3 minutes prior to
engine shutdown. A guide to taking screenshots can be found in THIS solution.
- Inlet and Outlet NOx values should be within 40 parts per million (ppm) of one
another just before the engine shuts down. Shown below is an example of how a graph
with two properly functioning sensors will look:
3. If no issues are found with the sensor readings from the NOx Conversion review, the
sensors are not the source of the conditions causing the codes to log. Further diagnostic
steps of other components will need to be performed to determine the cause of the faults.
4. If this solution is being reviewed for P20EE, P207F, P225E or P103C, the DEF Dosing
Valve Solution for the same DTCs should be reviewed for further information.
5. If diagnostic steps do not locate a root cause for the code(s), open an eService case with
Dealer Technical Support
- The screenshot(s) taken of the NOx conversion screen prior to engine shutdown (as
shown in the screenshot above) should be attached to the case.
- A complete summary of all tests performed along with numeric measurements, a
DTC Readout, and any information concerning previous visits and parts replaced must
be included when the case is opened.
• "Ok", "Good" and "Followed GD" are not acceptable descriptions of
tests performed and test results.
- Add the solution numbers for all CBR articles followed.
Internal comments (BO)
NOTE TO DTS: If the offset between sensor readings observed in the NOx Conversion
is greater than 40ppm, contact Nataraj Bhat for quick evaluation of the NOx conversion
test. (we have rarely seen this until now).
Solution visibility
Dealer distribution
Function(s)/component(s) affected
Function affected
DEF Dosing , SCR , 1 1 0 EMS , 2 1 0 ACM , Diagnostic tool
Function Group
Function Group
254 catalytic converter; exhaust emission control equipment , 258 emissions aftertreatment
Customer effect
Main customer effect
regeneration , diagnostics/methodology , efficiency/abnormal behavior , fault code
/display
Fluid implicated
AdBlue
Lights/Messages on
Driver's information warning pictogram
information display
Fault code(s)
OBD 2013 Diagnostic
Trouble Codes
P221A , P103C , P207F , P20EE , P2201 , P225C , P225E
Conditions
Vehicle operating mode
Frequency of occurrence of
problem
when driving , when stationary
random
Administration
Author
UT0031H
Dealer ID
UT0031H
Last modified by
RU4469V
Creation date
09-04-2018 19:04
Date of last update
25-04-2018 15:04
Review date
01-11-2019 00:11
Status
Published
NA_Reviewer
Nataraj Bhat
NA_Author_Group
GTT