Engine Controls - MIL ON/Lean Condition DTC's: Overview
01 MIL On, Lean Condition24 09 06
2018619/2
April 1, 2009
Supersedes Technical Service Bulletin Group 24 number 08-43 number November 7, 2008 for reasons listed below.
Vehicle Information
Condition
- MIL on.
- One of the following DTCs for lean mixture adaption for one or more cylinder banks is stored in the ECM:
- DTC P2177 (System too lean off idle, Bank 1).
- DTC P2179 (System too lean off idle, Bank 2).
- DTC P2187 (System too lean at idle, Bank 1).
- DTC P2189 (System too lean at idle, Bank 2).
This condition does not affect drivability.
Technical Background
Production Solution
New software in the Engine Control Module (J623) resolved the problem.
Service
1. Follow all instructions in the attached TSB 2011732 00 Software Version Management (SVM), operating instructions.
2. Update the ECM (J623) using the SVM action code as listed in the table if necessary.
3. After SVM is completed, put ECM in basic setting MVB 032.
4. Let engine idle for 5 minutes, then drive vehicle for 5 miles with varying load conditions.
5. Recheck the mixture adaptation values in the measured value block 032.
6. Mixture adaptation value blocks 1 and 3 (idle speed) should be ± 2.5% and value blocks 2 and 4 (part load) should be ±10%. If the mixture adaptation values are within these specifications, no further work is necessary.
7. If the adaption values are still outside the specification, open a new repair line on the Repair Order and continue diagnosis.
Mixture adaption faults can be related to (but not limited to) the following components:
a. Check air filter installation. The air filter must be the factory air filter element that is clean, dry and properly seated in the air box assembly.
b. Use leak detection spray G 001 800 A1 to check the intake system for false air.
The leak detection spray is drawn in with false air through vacuum into the intake system. The leak detection spray reduces the ignitability of the air/fuel mixture. This leads to a drop in engine RPM and a change in oxygen sensor values.
With false intake air, the actual lambda value MVB 031/ value 1+3 goes up, and the lambda control value MVB 033 / value 1+3 goes down.
Warranty
All warranty claims submitted for payment must be in accordance with the Audi Warranty Policies and Procedures Manual. Claims are subject to review or audit by Audi Warranty.
Additional Information
The following Technical Service Bulletin will be necessary to complete this procedure:
- TSB 2011732, 00 Software Version Management (SVM) Operating Manual.
All part and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Dept. and service manuals for the latest information.