Exhaust System
31
Operating Mode in the RS4
The secondary air system operates in much the same way
as that in the Audi Q7 engine. The difference here lies in
the way the combination valves open and close.
The air path from the secondary air pump to the
secondary air duct in the cylinder head is opened by
means of a vacuum unit on the combination valve. The
vacuum unit is controlled by the Secondary Air Injection
(AIR) Solenoid Valve N112 via the ECM.
The basic engine in the Audi Q7 and the high-revving
engine in the RS4 have different fitting locations for the
secondary air system. In the Audi Q7, the secondary air
system is fitted at the engine front end on the input side
of the ribbed V-belt, while in the RS4 it is fitted at the
output end of the engine.
Audi RS4 Secondary Air System
Air Filter
Combination Valve with Vacuum Unit
(vacuum controlled)
Secondary Air Injection (AIR)
Solenoid Valve N112
Secondary Air Pump
Reference:
For a description of the operating mode
this system, please refer to
SSP 921903 – The V8-5V Engine,
Construction Features and Functions.
Summary of Contents for 4.2-liter V8 FSI
Page 1: ...Self Study Program 921603 Audi 4 2 liter V8 FSI Engine Service Training...
Page 4: ...ii...
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