[Wageslave]

Hello all, I have a 2001 GLX New Beetle with a 1.8T engine. I have been through a bunch of crap since I took this thing on as a basket case project, but have mostly been able to figure everything out and get it running well. Recently, I have been hearing noise after the vehicle is shut off that does not go away regardless of how long it sits. I pulled the fuse for the secondary cooling pump, which makes it stop, but the noise continues until I pull the battery.

I jacked up the vehicle and tracked the noise down to the vacuum pump. The pump itself seems to work properly, but it seems like the relay that controls it is sticking.

Where is the location of the relay that controls the vacuum pump located? I think there is a block under the dashboard, but I haven't seen it since the interior was reassembled. Any help would be much appreciated.

 

[billymade]

#10 Protective housing
-For Secondary Air Injection (AIR) Pump Relay -J299-
-Secondary air system

Volkswagen Workshop Manuals > New Beetle GLS L4-1.8L Turbo (AWV) (2001) > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Electronic Throttle Control Module > Component Information > Locations

New Beetle GLS L4-1.8L Turbo (AWV) (2001) > Volkswagen Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Computers and Control Systems > Electronic Throttle Control Module > Component Information > Locations

workshop-manuals.com

wiring diagram:

Volkswagen Workshop Manuals > New Beetle GLS L4-1.8L Turbo (AWV) (2001) > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Emission Control Systems > Air Injection Pump Relay > Component Information > Diagrams > Diagram Information and Instructions

New Beetle GLS L4-1.8L Turbo (AWV) (2001) > Volkswagen Workshop Manuals > Relays and Modules > Relays and Modules - Powertrain Management > Relays and Modules - Emission Control Systems > Air Injection Pump Relay > Component Information > Diagrams > Diagram Information and Instructions

workshop-manuals.com

location on firewall with protective plastic cover (remove: #53):

Volkswagen Workshop Manuals > New Beetle GLS L4-1.8L Turbo (AWV) (2001) > Powertrain Management > Emission Control Systems > Air Injection > Air Injection Pump > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 2601-01 > Jun > 01 > Secondary Air Pump - Inoperative > Page 4589

New Beetle GLS L4-1.8L Turbo (AWV) (2001) > Volkswagen Workshop Manuals > Powertrain Management > Emission Control Systems > Air Injection > Air Injection Pump > Component Information > Technical Service Bulletins > All Technical Service Bulletins: > 2601-01 > Jun > 01 > Secondary Air Pump -...

workshop-manuals.com

 

[billymade]

This video shows a mark iv golf but is in the same location:

 

[Wageslave]

My secondary air injection pump is working normally. My issue is with the vacuum pump for the brake booster (underneath, next to the catalytic converter on the drivers side). It wants to continue running unless the battery is pulled.

I am wondering if the brake light switch could possibly be the cause, as the dealer just changed it out under recall a few weeks ago.

 

[billymade]

Did you check the relay? Do you have a automatic or standard transmission?

Sounds like you are referring to this:

Brake System Vacuum Pump V192

Volkswagen Workshop Manuals > New Beetle GLS L4-1.8L Turbo (AWV) (2001) > Brakes and Traction Control > Power Brake Assist > Vacuum Pump, Brakes > Component Information > Testing and Inspection > Brake System Vacuum Pump V192, Electrical Check

New Beetle GLS L4-1.8L Turbo (AWV) (2001) > Volkswagen Workshop Manuals > Brakes and Traction Control > Power Brake Assist > Vacuum Pump, Brakes > Component Information > Testing and Inspection > Brake System Vacuum Pump V192, Electrical Check

workshop-manuals.com

 

[Wageslave]

It is an automatic transmission. I haven't got a chance to get back out to look for the relay yet, as it is about 10 degrees outside.

 

[billymade]

Good background info:

Self-Study Programme 257

Electric vacuum pump for brake servo unit

http://www.volkspage.net/technik/ssp/ssp/SSP_257.pdf

 

[billymade]

Looks like the 2001 on VW models; have a relay and a pressure sensor, either could cause the pump to stay on. Based, upon what I have seen; the vacuum hard line, that goes from the brake booster, down to the pump, commonly cracks/splits and causes a vacuum leak. So, the brake booster, vacuum line; could cause the pump to keep running, in attempt to get the vacuum up to normal levels, then the pressure sensor, would kick off the vacuum pump. Otherwise, on the electrical side of things; the relay could be defective, the pressure sensor defective or the pump/controller could be bad.

It would be helpful, to have access; to a VW factory level scan tool, like VCDS or OBDEleven, so you could read related trouble codes and do output testing, etc. A typical, obd II scan tool; would probably, not be able to read brake related vw factory trouble codes or access, the controller, do bi directional control (output) testing, etc.

 

[Wageslave]

That was a good read. I will try to drop the pump down and check the hose when I get the chance. I will also try probing the ECM command pin to see if it is telling it to run or not. I'll let you know what I find. Thanks!

 

[billymade]

I had to replace the vacuum hose/pipe; on a 2005 new beetle convertible with a 2.0L and it was split on top, at the plastic angled connection, to the brake booster. Replacement, was somewhat involved; as it goes all the way down to the pump; I was using a lift and that made it easier but I still had to remove the pump, to get things disconnected, reconnect the new vacuum hose (it used a crimp Oetiker/PEX style pinch clamp; to keep it secured). The hose isn't cheap; I got it from my local VW dealer but being a safety issue, replacement was a necessity. The aftermarket is starting to reproduce these but at the time; I wasn't able to find one, other then genuine vw (you might try searching; see, if they make them now).

 

[Wageslave]

Well, I got a chance to get under the beetle again last night. When I hooked the battery back up, the pump ran super weakly then stopped, so I am thinking that at the very least the pump has failed from running for hours on end. It is fairly cheap (relatively) to replace, so I will probably order a new one and go from there.

 

[billymade]

Did you inspect the plastic vacuum pipe; that goes from the brake booster to the pump? They commonly split @ the brake booster connection; that was my problem. If you find the cracked/split hose; many times, you can wrap it with electrical tape and use a hose clamp, as a temporary fix, to diagnose things and install a new one, after you order one.

 

[Wageslave]

Did you inspect the plastic vacuum pipe; that goes from the brake booster to the pump? They commonly split @ the brake booster connection; that was my problem. If you find the cracked/split hose; many times, you can wrap it with electrical tape and use a hose clamp, as a temporary fix, to diagnose things and install a new one, after you order one.

I will check when the part gets here. It is parked while this whole snowstorm thing is going on anyways, so I am in no huge rush.

 

[Wageslave]

A little bit of an update, I got the vacuum pump loose enough to inspect everything. The hose down to the vacuum pump was actually in pretty good shape, but the clip that unlocks the connector was missing so I could not unhook the connector without breaking anything. I reassembled everything and took it to town on a test drive. No more noises after shutdown, but on the way home my transmission stopped shifting properly. Shifting between 2nd and 3rd every 3 seconds or so.

Needless to say, this project is on hold for a while.

 

[billymade]

There are a number of possibilities on shifting issues; first step, would be scanning with a VW factory level scan tool and see, what trouble codes, live data reveal. Many problems can be external (wiring harness damage, failed sensors, shifter assembly broken, etc), then the typical sticking valve body solenoids or internal ribbon harness damage and worst case scenario, internal damage (hard/soft parts), problems, requiring a pull, disassembly to evaluate things, find the problem (full rebuild). Here is a video, showing the use of VCDS by Ross Tech; to read trouble codes and view live data:

VCDS® HEX-V2® Enthusiast
- USB Interface -

VCDS with HEX-V2 Enthusiast | Ross-Tech

Once, you get the diagnostic info and narrow down the problem; you can see, if you can fix it yourself and/or decide, if it is a cost effective repair, that may need a professional to address. Correct diagnosis, can bring clarity to the problem and help guide you, on what to do next. When, you move forward; keep us in loop, tell us what you find, what is revealed and we can go from there, thanks.