How to safely work on the VW Touareg hybrid and disconnect the battery pack

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.

Disclaimer: In addition to the regular disclaimer and Terms of Use Agreement, remember that the electrical system has more than enough juice to cause serious injury or death.  Do not work on the engine, power module, battery pack, or high voltage lines unless you are trained and qualified.  These articles are only to teach you about the systems on your car.  They do not qualify you as an automotive technician trained to work on these cars.

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.

vw touareg hybrid safety line voltage disconnect

See part 2 here:


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