Fehlersuche Climatronic | Posts 16+

Hello Peter,
The fan located behind the radiator is controlled by the coolant fan control unit J293. The switch states of pressure sensor F129 are evaluated by both the Climatronic control unit and the radiator fan control unit.

Whether the control units for the Golf IV and Passat 3B are identical should be determinable by checking the part numbers.
How familiar are you with using a multimeter?
Can you rule out excessive contamination on the condenser?

Regards,

Andy.

'Could it be that the fuse for the second stage is defective? On a Golf 4, it's a fuse located on the battery.' Let's test it!

Hi,
Okay, so if the fuse is blown, then when you short-circuit the pressure switch, the radiator fan wouldn't go into the second speed setting. That's how he does it, as far as I understand.

Best regards, Andy.

@Andy & Julian,

I'll still check the fuse, just in case.

The capacitor looks okay as far as I can tell; I've also tried cleaning it.

I can handle a multimeter:).

Greetings.
Peter.

@Perly:

Hi,

Have you taken a close look at the strip fuses? They tend to corrode at the connections, which can lead to intermittent failures. My ABS in my Golf III had the same problem when it got too hot - the fuse strip corroded.

@Roger,

Thank you for the tip.

Do you or anyone else know where the fuses are located in a Passat V6 gasoline engine?

There's nothing on the battery.

Thank you.
Peter.

Have you checked the shock absorber strut housing? On the Golf III, they were located under a small, transparent cover. Otherwise, I would consult the instructions.

My problem is solved .

And I would like to share the solution with you.

Thanks to the information from Andy, localizing the error was relatively simple (for me, apparently not for a VW workshop ).

It turned out that the second stage of the fan was not activated.
I first checked all the connections of the pressure switch. In doing so, I noticed that the connector located near the servo oil reservoir was not properly connected. A pin inside the connector had slightly shifted. This meant that she only had contact when the plug was fully pushed in.

I then figured out with Andy Plan that this connector tongue belongs to the contact of the pressure switch, which activates the second stage. Voilà, the error is fixed . For next to nothing.

The last VW dealer then reimbursed me for the pressure sensor , but not for the troubleshooting .

Everything has been working perfectly since then . Even in hot weather . (I was so overjoyed with my success that I forgot to inform you, I'm ashamed.... .)

Greetings.
Peter.

Hi Peter,

Thank you for the feedback.


Best regards, Andy.