Engine Controls - MIL ON/DTC's P0421/P0431
01 08 342012357/3
December 22, 2008.
Supersedes Technical Service Bulletin Group 01 number 06-14 dated August 22, 2006 for reasons listed below.
Affected Vehicles
01 Malfunction Indicator Light (MIL) ON, DTC P0421 or P0431 Stored in DTC Memory
Condition
MIL on and one or both of the following DTC's are stored:
- P0421 - Warm up catalyst, bank 1, efficiency below threshold
- P0431 - Warm up catalyst, bank 2, efficiency below threshold
Applies only to ECM's with the following part numbers:
- 4B0 907 551 T (A6)
- 8D0 907 551 L (S4).
Technical Background
The ECM may diagnose the Warm up Catalytic Converter incorrectly under high engine load conditions.
Production Solution
The diagnosis threshold has been changed in later ECM's.
Service
If ECM software level of is lower than 4000:
- ECM requires a software update (flash). DO NOT REPLACE CATALYTIC CONVERTER(S).
If Software Level of ECM is 4000 or higher:
- Replace affected CATALYTIC CONVERTER.
Tuned ECM or TCM requirements:
NOTE: Any "Update Programming" procedure (flash) may overwrite any "TUNED" ECM or TCM programming.
A "TUNED" ECM or TCM is described as any ECM or TCM altered so as to perform outside the normal parameters and specifications approved by Audi of America, Inc.
If you encounter a vehicle with a Tuned ECM or TCM, your dealership must do the following before performing any procedure that updates ECM or TCM programming:
- Notify the owner that their ECM or TCM was found to have been tuned
- Notify the owner any damage caused by the tuning of the ECM or TCM (including any adverse emissions consequences) will not be covered by Audi of America, Inc. warranties.
- Obtain the owner's written consent (see Control Module Tuning form) for any requested repair under warranty or outside warranty that requires flashing, which will automatically overwrite the Tuned program.
Vehicle requirements:
- Ignition switched ON.
- VAS 5051/5052 switched on, connected to vehicle (using K-lead adapter VAS 6017 A) and must have sufficient power supply at all times during procedure.
- Battery MUST have minimum no-load charge of 12.5 V (failure to maintain voltage during update process can lead to ECM failure).
- No appliances with high electromagnetic radiation (i.e. mobile phones ) around the vehicle.
- Also refer to Required Parts and Tools.
NOTE: Non-observance of the following points may lead to ECM failure! VAS 5051 or 5052 must always be connected to the approved power supply at the approved voltages. Under no circumstances should the power supply be interrupted or the diagnostic connector unplugged during the flash procedure. Any appliances with high electromagnetic radiation (i.e. mobile phones) must be switched OFF.
1. Update - Programming (flashing) preparation
Start Screen
- Insert Update-CD into CD drive as soon as Start Screen appears in order to place the tester into the flashing mode.
- Select: Vehicle Self-Diagnosis >> 01 - Engine Electronics.
Print screen and attach printout to the repair order.
If ECM software level (black arrow) is 4000 or higher:
- Do not complete this Technical Bulletin.
- Select: 06 End Output (white arrow).
- Replace affected Catalyst.
If ECM software level is lower than 4000:
Before starting the Update-Programming procedure, the fault memories of all systems need to be interrogated and existing DTC's need to be printed and erased.
- Select backward button to return to Start Screen.
- Select: Vehicle Self Diagnosis >> 00 - Collection Services >> Check DTC Memory - Complete System, which will interrogate all fault memories.
Once fault memories are erased, Function ended will appear in upper left corner of screen.
- Select forward button and print all DTC's.
- Erase all DTC's by entering the affected systems individually.
- Return to Start Screen.
Before starting the Update-Programming Procedure, the radio needs to be disconnected from the electrical system.
- Switch ignition OFF.
- Access and record radio code.
- Pull radio out from instrument panel enough to access electrical connectors.
- Disconnect all electrical connectors (arrows) from multi-pin connections.
- Switch ignition ON.
2. Update - Programming (flashing) performing
From Start Screen:
- Select: Vehicle Self Diagnosis >> 01 - Engine Electronics >> Update - Programming (lower black arrow).
Tip: The "Update - Programming" function will appear whether the ECM requires updating or not, whenever the Update-CD ROM is inserted in CD-Drive of tester.
After selecting Update - programming function, NEW program version and approximate timing for update are displayed on the VAS5051/5052 screen.
- Select > button, which will start the programming procedure.
The previous data in the ECM is being erased and the new data is being transferred to the module from the flash CD. (Approx. flash time is 17-19 minutes.).
NOTE: Once Update - Programming function has been started, switching ignition OFF or disconnecting the diagnostic connector may completely destroy the ECM.
If, during the "Update - Programming", this fault message is displayed:
- Select "Repeat" button (arrow) and the "Update Programming process" will be started from the beginning.
- DO NOT select the "Cancel" button! DO NOT switch OFF the ignition!
- Confirm that VAS 5051/5052 diagnostic tool power supply is adequate and that ALL appliances with high electromagnetic radiation (i.e. mobile phones) are switched OFF.
The tester will request you to cycle the ignition.
- Switch ignition OFF.
- Wait 20 seconds and switch ignition back ON.
Similar Screen appears, once "Update Programming" (flashing) is complete:
Old ECM Part No. and software level are still displayed on the screen (arrows). New ECM Part No. and software level are not displayed until process is complete and fault memories have been erased.
- Print screen and attach printout to the repair order.
- Select forward button
The tester will request you again to cycle the ignition.
- Switch ignition OFF.
- Re-install the radio and re-connect all electrical connectors from multi-pin connections.
- Switch ignition back ON.
- Select forward button.
3. Fault memories, erasing after "Update-Programming" (flashing)
Due to the CAN bus system, fault messages will be stored in various Control Modules during programming.
- Select forward button to erase ALL fault memories. (system takes approx. 15 minutes to erase all fault memories).
Once fault memories are erased, Function ended will appear at bottom of screen.
- Select backward button to finish the ECM update.
Updated software level 4000 will appear.
- Print screen and attach printout to the repair order.
- Select "Go to" >> "Exit" to return to Start Screen.
ECM reprogramming is now completed.
- Verify ECM coding.
- Set Readiness Code.
Warranty
Required Parts and Tools
- VAS 5051 or VAS 5052 with Basis-CD A.08.01 and the Brand-CD A.08.47 (or later) is required for the ECM Update.
Additional Information
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.