TECH TIP
DX3 NOX SENSOR MONITOR
SUPERSEDES TECHTIP 22-025
GROUP: 0-GENERAL
TECH TIP NO: 23-019
DATE: 4/21/23

SUBJECT VEHICLES
11MY-21MY Conventional Trucks equipped with a J08
engine or Cab Over Engine (COE) equipped with a J05
engine.
OVERVIEW:
The purpose of this procedure is to provide instructions
in how to properly record Nox Sensors using DX3
Note: This technical tip is provided as technical
information and is not authorization for a warrantable
repair.
REPAIR PROCEDURE:
Note: Be sure to change Unit Settings in DX3. Click
Settings (gear in the upper right) > Unit Setting and
then mirror the settings below, click OK. Log out of
DX3, then Log back in to hold new settings for future
DX3 connections and data monitoring.
.

Note: Exhaust temperatures MUST be at ambient
temperature prior to performing this test.
1. Connect DX3 and allow Read Out to complete.
Click Customization, in System select Engine CAN,
and scroll to locate DPF Soot Amount Piling Up. Set
the soot level to 3.5g/L for a manual regen, and click
Write, follow DX3 to complete writing of soot level
Note: Key must be ON with the Engine OFF to write or
change any value. Ignition must then be turned off for
60 seconds to finalize writing of value, and turned back
on

Write Value

Type Soot Level 3.5g/L

Customization

2. Select “Data Monitor and Active Tests” then select
“Data Monitor”

Data Monitor and Active Tests

Data Monitor

3. Select Inspection Menu on the left, Data Monitor
on the right, and then Read from the parameter list

4. Select Distribution

5. Select the correct template for NOx and then select
Open

6. Select OK to confirm pre-selected parameters and
start recording

7. Start the truck, start the DX recording and then
press the Manual Regen switch on the dash to start
manual regen. Record until manual regen has
completed.

Start Recording, record
until regen completes.

8. Click the Stop in the lower right of DX3 to stop the
recording. In the save box, label the recording, be
sure to include the test name and VIN or TechAssist
Case number, click OK

Label Recording

Click Stop

9. Click Read, click on the Work Date header a couple
times to sort recordings by work date, highlight the
recording and click Replay
Work Date Header

Click Read

10. Graph data to review. Graph both Nox Sensors in
the same graph.
Note: Please review our DX3 training course as
needed for any graphing questions

11. Graph Engine RPMs separately

Note: If you are not able to determine judgment,
please follow TechTip #22-019 Sending DX3
Files to TechAssist. Create a TechAssist case
outlining the customers concern, diagnosis performed
and related DTC’s, then attach file(s) for review.