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Phaeton 2003 ➤
6-cylinder injection engine - Edition 02.2014
2
Secondary air system
Function
The secondary air system blows air in behind the exhaust valve
for max. 65 seconds after a cold start (+15 °C ... +35 °C coolant
temperature). This produces an oxygen rich exhaust gas, causing
afterburning and reducing the heat-up phase of the catalytic con‐
verter. Actuation is performed by the engine control unit via the
secondary air pump relay - J299- to secondary air inlet valve -
N112- and combination valve. Additionally, after each subse‐
quent engine start (up to max. 85 C engine temperature), the
secondary air system will, after a 20 second delay, switch in for 5
seconds during idling and will be checked by the self-diagnosis.
Assembly overview - parts of secondary air system
Checking combination valve
2.1
Assembly overview - parts of secondary
air system
Note
Location of secondary air pump relay - J299-
176
Rep. gr.26 - Exhaust system
⇒ page 176
⇒ page 178
⇒ page 178
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