You can also test outputs from IO Setup screen. Ensure you're connected to the ECU, everything is powered etc, then select from the drop down box next to the output pin you would like to test, the type of test you want to perform. 

Remember to set it BACK to the correct option after carrying out a test, and you can only test one output at a time!

Let's test the fuel pump in the following example:

We know we wired the fuel pump relay to LS 1 on the ME221 Wire-In. The other side of the really is powered to 12V, so when we toggle LS 1 (Low Side 1, e.g it switches to ground) the fuel pump should turn off and on.

We choose “TEST: SLOW TOGGLES” from the drop down box next to LS 1, as shown below. We will then hear the fuel pump relay/fuel pump, turn OFF and ON every couple of seconds. If it does not, we have a wiring issue!

The next thing we may wish to test could be a coil or an injector output. It is important to note we shouldn't turn the coils on for long periods of time (over several milliSeconds) as it may damage the coil or the ECU’s drivers, so for that, we should use TEST: INJ/COIL (5ms - 3s). This will drive the output for 5 milliseconds, every 3 seconds. Enough for the injectors to click, or the coils to fire off a spark.

The other test functions are ‘ON’,  ‘OFF’ and ‘Fast Toggles’ - which are self explanatory.

If you wish to test unused outputs, follow the below circuit. You can then wire the "test LED" into any of the unused Low-Side, Injector or Coil outputs, and see visually if the output is working when setting an output to a test mode as above.