One concern of working on hybrid cars for DIY’ers is how to work around the hybrid electrical system. It’s not only amps or only volts that is dangerous, it’s enough of the combination of enough either volts or amps that can injure you. Comparing electricity to water, you can think of amps as the volume of water and volts as the speed that it moves. You’re not going to get swept away in a river unless there’s enough water and it’s flowing fast enough.
The electric safety line in the VW Touareg hybrid and Porsche Cayenne hybrid
The battery pack in these cars is 288 volts and more than enough amps to cause serious injury. If it has enough energy to move a car it has enough energy to jolt you. Therefore, take safety precautions when working on them. There are a few safety measures:
• The electric safety line with safety connector
• The ignition lock
• The battery regulation control unit relay
• The airbag control module
• The maintenance connector
In this first post in a series, let’s look at the safety line and connector. The safety line guarantees that the entire high voltage system’s voltage is turned off as soon as a high voltage component is disconnected from the system. Together with a locking bar, the safety connector forms a mechanical lock, which prevents the high voltage lines from being disconnected while voltage is present. The safety line is an electrical circuit that is closed by safety connectors. If this circuit is opened by removing the safety connectors, the high voltage system shuts off.
The safety connectors have to be removed before high voltage lines can be disconnected from the high voltage components. This guarantees that the system is not conducting voltage when the lines are disconnected. It is shown below.