User manual

Output Tests cont. - Section 18-B
On most systems, the Output Tests function is only available when the Engine is not
running.
It is perfectly normal to see a "short to ground" message in the process of running Output
Tests. 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 power supplied all the time and the ECU
completes the circuit (and turns the actuator on) by pulling the other side to ground.
Warning:
Do not use the Output Tests 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 strongly suggest you refer to the Factory Repair Manual for your specific car
before running Output Tests on any Control Module so you will know what to expect!
If you try to perform Output Tests on an Airbag controller, the following warning will pop up:
For example, in the VW Touareg, a specific procedure must be performed to be able to
start the vehicle if Output Tests on the Airbag Controller have been performed.