Output test
Edvinas avatar
Written by Edvinas
Updated over a week ago

The Output Test function is used to test a control module's electrical outputs (and the wiring that connects it to the various devices). To access the function follow the instructions:

  • Connect to your vehicle by pressing


  • Open the list of control units by pressing


  • Select the needed control unit by tapping on it


  • Open the output test by pressing


  • You will be able to select the needed output test by selecting "Selective" and apply by pressing


  • Once you will open it, you will get already selected output test from the list, which is located as a first. You can change the output by pressing


  • The message "Not available" is shown because the output test has not started yet.

  • Select the needed output test by tapping on it and apply by pressing


  • Start the output test by sliding


  • The output is displayed with the values. Output tests include simultaneous measuring data when available from the control module.

  • By running this particular output, now the left turn signal lights will work on the vehicle.

  • It will show three times 100% because on this vehicle left turn signal will work on the front, mirror, and rear. Since there is no forth value, it will show "Not available". 100% means that each section of the left turn signal is working at 100% brightness.

  • Stop the output test by sliding

    . (Do not leave the output test running while closing the application or leaving this section).

The use of Sequential output test:

  • Select the sequential and apply by pressing


  • This method can be used to check each channel of the control unit output test. It will automatically run through all output tests at the time.

  • Start the process by sliding


  • It will show you which output test currently active, in this case, "Parking light switch".

  • You will also be able to see the values of the current output test.

  • You can go to the next output test by pressing


  • By pressing "Next" you will be able to go through all the output test on this control unit.

  • Stop the process by sliding



  • The outputs that can be tested and the sequence in which they become active are controlled strictly by the control module.

  • If you start the output test and get back to the main menu of the control unit test sequence will still be active.

  • Most control modules will permit the output test sequence to be run only one time per session. If you need to run the sequence again, you must cycle the key OFF and ON.

  • Some output tests require an additional action before they become active. Fuel injectors are a common example. To activate a fuel injector you must press (and in some cases release) the gas pedal. Exact details can be found in your factory repair manual.

  • In most systems, the output test function is only available when the engine is not running.

  • It is normal to see a "short to ground" message in the process of running an output test. The ECU identifies which output it is currently testing by sending a fault-code number. On many ECUs the full text for this fault code includes "short to ground". Why? Because one side of the actuator in question has 12V on it all the time and the ECU completes the circuit (and turns the actuator on) by pulling the other side to the ground.


Do not use the output test function on any system while the car is in motion. Running output tests on the ABS brake system can temporarily disable the brakes entirely and cause individual wheels to lock and unlock. We suggest you refer to the factory repair manual for your specific car before running an output test on any control module so you will know what to expect. Running output tests on the airbag control unit can lead to unexpected results such as a vehicle that will not start. Running output test is supposed to make the airbag controller generate a simulated crash signal to the rest of the systems in the vehicle so that unlocks itself and shuts various things OFF.

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