MIL ON - DTC P0411 Stored

Group: 01
Number: 00-06
Date: Dec. 20, 2000

Subject:
Malfunction Indicator Lamp (MIL) ON, DTC P0411
(16795) Stored in DTC Memory

Model(s):
TT with 1.8L Turbo 2001 -->
(eng, codes ATC, AMU)

Supersedes T.B. Group 01 Number 00-05 dated Nov. 7, 2000 due to change in procedure

Condition

MIL is ON with DTC P0411 (16795) "Secondary air system incorrect flow detected" stored in DTC memory.

May be caused by a faulty Charge pressure bypass valve, since both the Charge pressure bypass valve and the Combi-valve for Secondary air system share a common vacuum source.

If Charge pressure bypass valve does not hold vacuum, there will not be enough vacuum during Secondary Air diagnosis to open the Combi-valve and the system stores DTC P0411 (16795) "Secondary air system incorrect Flow Detected" in DTC memory.

Service

Check Charge pressure bypass valve as follows:

- Remove upper engine cover.





- Disconnect vacuum line at bypass valve.

- Connect V.A.G. 1390 hand vacuum pump (or equivalent) to bypass valve.

- Operate vacuum pump to achieve at least 15 in. Hg (vacuum).

^ System should hold at least 15 in. Hg (vacuum).

If system holds at least 15 in. Hg (vacuum):

- Continue to diagnose DTC P0411 according DTC table in Group 01 of appropriate Repair Manual.

If system does not hold at least 15 in. Hg. (vacuum):

- Replace Charge pressure bypass valve.

- Clear any stored DTC's.

- Install upper engine cover.