Vacuum Hose Routing Diagram

[VroomTT]

I've searched AZ and beyond with no luck...

Anyone know where this can be found? Or have the ability to pull it up and post?

I'd like to get a better understanding of how everything works together and start analyzing what can be removed or improved

[jvitelli17]

can't help with diagram but x2 for this!

[VroomTT]

can't help with diagram but x2 for this!

I've been searching repeatedly, with no success. Somebody has to have this somewhere...

[VroomTT]

Bumping to the top

I'm seeing this as a re-occurring theme in more and more threads... Who can help us out???

[c0ntract_thrill]

I don't have a routing diagram, but I have component location diagrams. I didn't upload them all because I am too lazy, this is the essentials.

Here are the common vacuum connections in engine bay: Look at the Black Arrows for connections




#4 in this image





1 - Evaporative Emission (EVAP) canister purge regulator valve N80

Evaporative Emission (EVAP) canister purge regulator valve N80

2 - Mass Air Flow (MAF) sensor G70 with Intake Air Temperature (IAT) sensor G42

3 - Connector console

Pin assignment

Assignment of holder for connectors (right side)

4 - Valve 1 for camshaft adjustment N205

Rear view

5 - Camshaft Position (CMP) sensor G40

Cylinder bank 1

Rear view

6 - Engine coolant temperature (ECT) sensor G62

At coolant pipe behind cylinder head, bank 1

Rear view

7 - Fuel supply line

8 - Throttle valve control module J338

With Throttle drive (power accelerator actuation) G186 , Angle sensor -1- for throttle drive (power accelerator actuation) G187 and Angle sensor -2- for throttle drive (power accelerator actuation) G188

Rear view

9 - Oil pressure switch F1

Rear view

10 - Camshaft Position (CMP) Sensor 2 G163

Cylinder bank 2

Rear view

11 - Connector console

Pin assignment

Connector console beneath coolant expansion tank

12 - Valve -2- for camshaft adjustment N208

Rear view

13 - Engine Speed (RPM) Sensor G28

In transmission housing above ring gear

14 - Ignition coils with output stages

Cylinder bank 2

15 - 3-pin connector

For Knock sensor 3 G198

For Knock sensor 4 G199

Front view

16 - Secondary Air Injection (AIR) Solenoid Valve N112

Front view

17 - Intake Manifold Change-Over Valve N156

Front view

18 - 3-pin connector

For Knock Sensor (KS) 1 G61

For Knock Sensor (KS) 2 G66

Front view

19 - Ignition coils with output stages

Cylinder bank 1

20 - Secondary Air Injection (AIR) Pump Motor V101




Installation location of Fuel Pump (FP) Relay J17

Position - arrow 1 - on 9-position relay carrier on left of drivers footwell.


1.1 - Coolant Circulation Pump Relay J151 (hot countries only)
1.2 -Not used
2 -Secondary Air Injection (AIR) Pump Relay J299
3 -Motronic Engine Control Module (ECM) Power Supply Relay J271
4 -Relay for automatic transmission
A -Engine electronics fuse S282
B -Secondary air pump fuse S130
C -Not used




Assignment of holder for connectors (right side)

1) 6-pin connector for Heated Oxygen Sensor (HO2S) G39 and Oxygen Sensor (O2S) Heater Z19 before catalytic converter, bank 1
2) Connector for starter (terminal 50) and generator
3) 2-pin connector for camshaft timing control, bank 1
4) 4-pin connector for Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G130 and Oxygen Sensor (O2S) Heater 1 (behind Three Way Catalytic Converter (TWC)) Z29 , bank 1


Intake Manifold front




1 Vacuum unit for intake manifold changeover
2 Knock Sensor (KS) 1 G61
3 Knock Sensor (KS) 2 G66
4 Intake Manifold Change-Over Valve V156
5 Secondary Air Injection (AIR) Solenoid Valve N112
6 Knock sensor 3 G198
7 Knock sensor 4 G199




1) Valve -2- for camshaft adjustment N208
2) Camshaft Position (CMP) Sensor 2 G163 , cylinder bank 2
3) Oil pressure switch F1
4) Throttle valve control module J338
5) Engine coolant temperature (ECT) sensor G62
6) Camshaft Position (CMP) sensor G40 , cylinder bank 1
7) Valve 1 for camshaft adjustment N205



Secondary Air Injection (AIR) Pump Motor V101



Leak detection pump (LDP) V144

[VroomTT]

Those are a big help, thanks c0ntract!

Gotta ask, Where are these from?

[c0ntract_thrill]

Those are a big help, thanks c0ntract!

Gotta ask, Where are these from?

The Bentley

[VroomTT]

The Bentley

Gotcha. I was kinda surprised this hasn't been vetted out on here already. Flow diagrams are so readily available for 1.8t's and 2.0t's.

As I learn more about how everything functions on the 4.2, my aim will be improving/deleting. Starting with the flapper hose and following it all back as much as possible. Several of the mini hoses are ready to crack, so tackling it all at once is the plan.

[c0ntract_thrill]

There are a few audi sites that are more technical than here that have hosted some information.

Regardless, if you're looking for detailed information a Bentley is a must.

[VroomTT]

I also just noticed this in my S4...



I wish mine wasn't all messed up, but at least it's readable. Would love to replace it with a new one.