Ignition Switch Replacement VW Golf 3 (Articles)

What exactly is the ignition switch (ZAS)?

The ZAS is the contact point located at the rear of the ignition switch, which controls the flow of electricity.

It has several 'outlets':
- Mounting point for parking light.
- Radio position.
- Contact for X-Release products (wipers, blowers, headlights).
- Ignition
- Starter motor

How do I actually tell if the ZAS is defective?

- If the ignition cannot be turned on.
In this case, short-circuit the '30' and '15' terminals on the ZAS (ignition control unit) - if the ignition now starts, the ZAS needs to be replaced.

- If, during the starting process, the oil warning light and the charging light go out, and the engine does not start.
So, during the starting process, the ignition system (terminal 15) is failing - however, the starter motor is turning normally.
In this case, however, the engine starts when the vehicle is towed.

- The starter motor is not turning.
In this case, first check if there is voltage at terminal 50 on the starter motor (small cable) when starting.
If it doesn't measure whether the ZAS is cutting off the 'start signal,' then replace it.

- The radio cannot be turned on using the radio button.
In this case, check if there is power on the red/brown wire at the ISO connector when the key is in the ignition. If not, the ZAS (Zündschloss Ansteuersystem) is most likely defective.
This contact (radio connection) often fails because an external radio was improperly connected.

-The blower, wipers, and headlights have stopped working.
In this case, the 'X-relay' might also be defective. This can be determined by bridging the terminals '30' and 'X' on the ZAS (Zentralausrücksystem). If everything works again after bridging, replace the ZAS.

- Parking light not working
If the parking lights on both sides are not working, but the side marker lights are, then the ZAS (central electronics module) may be defective. To check this, measure whether the ZAS is outputting power when the key is removed - if not, replace the ZAS.

In all of these tests, it is naturally assumed that the ignition switch is 'mechanically' sound and that the key can be turned to the respective position.

SWITCHING FROM ZAS:
- Disconnect the battery.
-> with airbag: wait for some time after disconnecting the battery.

- Remove the steering column cover (two screws from underneath).

- Remove the center section of the steering wheel.
-> Without airbag: Carefully pull the horn button forward and disconnect the cable.
-> with airbag: carefully loosen the screws from the rear and gently pull it forward, then disconnect the cable.

- Remove the steering wheel.
-> Wheel alignment.
-> Mark the steering wheel position.
-> Zentralmutter (24er? Remove the nut.
-> Remove the steering wheel.

- Remove the steering column switch.
-> unscrew the three set screws.
-> Carefully disconnect all connectors from the back.
-> Don't forget the plug from the ignition switch.
-> Possibly disconnect the connector from the reading coil, or pull the coil down from the lock.

- completely remove the bracket/holder.
-> Mark the position of the 'ignition switch holder'.
-> Insert the key to ensure the steering wheel lock is not engaged.
-> Unscrew the departure screw located on the lower left.
-> Remove the adapter sleeve (see below for more information!).
-> Pull the holder forward.

- Remove the ignition switch from the housing and replace it with a new one (using a small screw from the back).

- Installation is performed in reverse order.

- For vehicles equipped with airbags, turn the key to the 'ignition' position BEFORE connecting the battery!


Remove the adapter sleeve.
- Place the 'crimping pliers' on the cone so that the front part rests against the edge.
- Then, attach a puller to the pliers and rotate the part to remove it.
- Also, also hold the puller in place with a C-clamp as well.
- Gently screw the female part back onto the threads to avoid damaging them.
- Occasionally, a little 'bouncing' can also help.


This guide is for the Golf 3. However, the removal/function of the ZAS (Zündausfallüberwachung) is similar in other vehicles.


WORK ON AIRBAGS MUST ONLY BE PERFORMED BY TRAINED PERSONNEL!!