Golf Mk4
| Engine codes ARL, ASZ, AXR |
| 1 - | Vacuum unit |
| q | On engine codes ARL, ASZ for variable intake manifold changeover |
| q | On engine code AXR for exhaust gas recirculation changeover |
| 2 - | Exhaust gas recirculation valve -N18- (electro-pneumatic) |
| 3 - | Change-over valve |
| q | On engine codes ARL, ASZ for variable intake manifold flap -N239- |
| q | On engine code AXR for exhaust gas recirculation cooler -N345- |
| 4 - | Charge pressure control solenoid valve -N75- |
| 5 - | Non-return valve |
| q | White connection to variable intake manifold flap changeover valve → Item, to charge air control solenoid valve -N75- → Item and to vacuum reservoir. |
| 6 - | Vacuum reservoir |
| 7 - | Air filter |
| 8 - | Pressure unit |
| q | For charge pressure control |
| q | Integral part of turbocharger and cannot be replaced. |
| 9 - | Exhaust gas recirculation valve (mechanical) |
| q | Part of intake connecting pipe |
| q | Can only be renewed together with intake connecting pipe |
| 10 - | Vacuum connection |
| q | Between tandem pump and brake servo |
