Secondary Air System - MIL ON, DTC P0411 Set
Group: 01Number: 00-06
Date: Oct. 26, 2000
Subject:
Malfunction Indicator Lamp (MIL) ON, DTC P0411
(16795) Stored in DTC Memory
Model(s):
Golf, Jetta with 1.8L Turbo 1999, 2000
(eng. codes AWD, AWW)
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 vacuum reservoir (arrow).
- Connect V.A.G. 1390 hand vacuum pump to vacuum line.
- Operate V.A.G. 1390 to achieve at least 15in. Hg (vacuum).
^ System should hold at least 15in. Hg (vacuum).
If system holds at least 15in. Hg (vacuum):
- Continue to diagnose DTC P0411 according DTC table in Group O1 of appropriate Repair Manual.
If system does not hold at least 15in. Hg. (vacuum):
- Using Special Tool 3094 hose clamps or SNAP ON hose pinchers Model No: YA850 as equivalent, pinch vacuum hose (arrow) to Charge pressure bypass valve.
- Operate V.A.G. 1390 to achieve at least 15in. Hg (vacuum).
^ System should hold at least 15in. Hg (vacuum).
If system holds at least 15in. Hg (vacuum):
- Replace Charge pressure bypass valve.
- Clear any stored DTC's.
- Install upper engine cover.
If system does not hold at least 15in. Hg. (vacuum):
- Continue to diagnose DTC P0411 according DTC table in Group O1 of appropriate Repair Manual.