NOx Tester User Guide

The NOx Tester is a dedicated diagnostic tool for testing NOx sensors. Using OEM-level commands, it activates the NOx sensor’s heating function to simulate real-world operating conditions on the vehicle. By monitoring real-time NOx output data, the tool accurately determines whether the sensor is functioning properly.

After downloading the app, complete account registration and device binding first.

1. App Registration

Enter your email address
Request and enter the verification code
Log in to complete registration

2. Device Binding

Connect the diagnostic module to the 3‑in‑1 NOx sensor harness
Power the device using the compatible power adapter
On the app, connect via Bluetooth to locate and select your device’s serial number
Confirm to finish binding

3. NOx Sensor Testing

The 3‑in‑1 test harness includes three connector types:

Square 4‑pin
Flat 4‑pin
Flat 5‑pin

Match the connector to your NOx sensor:

Square 4‑pin: Commonly used on Cummins, Detroit, Paccar, Mack, Mercedes‑Benz engines
Flat 4‑pin: Typically used on Volvo engines

Important Power Note

Use a power supply that matches the sensor’s operating voltage:

12V sensor → 12V power supply
24V sensor → 24V power supply Incorrect voltage will prevent normal operation.

4. Running a Test

Tap NOx Test → Auto Detection to establish communication with the sensor
Tap Start to begin the test, which takes approximately 3 minutes
The sensor will heat up during testing — avoid touching the sensor probe, as it reaches high temperatures and may cause burns

During the initial heating phase, displayed values may be unstable. Use only the stable readings after full heating to evaluate sensor condition.

When the test finishes, a pop‑up will show the result: Normal or Abnormal. You may name and save the report, which can be viewed later in Diagnostic Records.

For additional technical support, please visit: www.proformanceusa.com