Attachment Bulletin # 010206
Group: 01Number: 02-06
Date: June 25, 2002
Subject:
Malfunction Indicator Lamp (MIL) ON, DTC P0411 Stored in DTC Memory
Model(s):
A4 1.8T 2000, 2001
(Eng. Codes ATW, AWM)
Condition
MIL is ON, Diagnostic Trouble Code (DTC)
P0411 "Secondary air system incorrect flow detected" is stored in DTC memory.
DTC P0411 may indicate a general fault in the Secondary air system.
Service
Suggested diagnostic procedure:
^ Vacuum line from Combination valve must be OK.
^ Supply line from Secondary air pump to Combination valve must be OK.
^ Relay for Secondary air pump checks as OK.
- Check the Combination valve with a vacuum pump.
If valve does not open or will not hold vacuum:
- Replace Combination valve (See Repair Manual, 1.8 Liter 4-Cyl 5V Turbo Engine Mechanical, Repair group 26 - Exhaust system, Emission controls Secondary air system, Secondary air system, function/components).
If valve opens and holds vacuum:
- Check intake side of Combination valve.
If exhaust gas residue is found on inside of Combination valve (intake side is black, see arrows):
- Replace Combination valve (See Repair Manual, 1.8 Liter 4-Cyl 5V Turbo Engine Mechanical, Repair group 26 - Exhaust system, Emission controls Secondary air system, Secondary air system, function/components).
- Verify proper operation of Secondary air injection pump -V101-.
^ A clean intake side indicates proper functioning of the Combination valve.
- Clear any stored DTCs using VAS 5051 or VAS 5052 diagnostic tool.
When procedure applies to vehicles within the New Vehicle Limited Warranty, use the table.