[50harleyrider]

I checked the pump unplugged with 12 v and it runs fine. Relay 373 in the 13 relay box and its' fuse are fine. Is there a module for the pump somewhere that could be bad? if anyone out there could send me a wiring diagram of the pump and its control would be great.

 

[PZ]

Does it not come on at all or did you get a code for it? I had one that threw a code on a 1.8T, but it worked fine. Found a bad vac line where the braided hose attached to the hard plastic line just past the coolant tank. It runs to the LDP (and vacuum reservoir if you don't have the blue tank under the driver's side headlight). It caused constant low vacuum which the system though was a bad pump.

 

[FrescoGreen01.5]

The ECM activates the 373 relay, which switches power to the vacuum pump. The exact fuses that power the relay coil and vacuum pump depends on which engine you have (1.8T or V6?).

There is also a "S131" Safety Fuse; the Bentley manual doesn't really identify where it is located.

 

[50harleyrider]

No luck. Still getting the open circuit fault. have replaced the pump and the vacuum sensor with known good units, verified the fuse and the relay are working but fault code keeps popping up. measuring block 8 in VAG shows pump activation but pump not running which trips the fault code. there are only 2 wires to my pump so I think the J542 module exists somewhere but where? Don't think it's integrated in the pump like the jettas so back to my post 1.

 

[FrescoGreen01.5]

Which engine does your 2002 have? Automatic transmission?

The schematics (in Bentley) are specific to engine and year.

 

[50harleyrider]

It's a 2001.5 2.8 automatic 4motion. if you have that part of the wiring diagram. Please pdf and email to me or post it here.thx