S4 V8-4.2L (BHF) (2004)
PROM - Programmable Read Only Memory: Customer Interest
Engine Controls - Rattle From Intake Manifold On Startup
24 08 84
2017369/3
December 17, 2008.
Supersedes Technical Service Bulletin Group 24 number 08-17 dated April 15, 2008 for reasons listed below.
Affected Vehicles
24 Rattling from intake manifold
Condition
Sporadic hard metallic rattling sound from intake manifold only after first cold start, audible for 1-2 seconds.
Technical Background
Early activation of the vacuum solenoid valves for the variable intake manifold by the Engine Control Module (J623) during cold engine starts may
cause the internal intake flaps to vibrate and create a brief rattling sound from the intake manifold.
Production Solution
New software in Engine Control Module (J623) resolved the intake manifold rattling issue.
Tip: Please explain to the customers that this new software is the latest software level with improved driving characteristics, which includes the
following changes:
-
The exhaust flap (if equipped) is always open, and no diagnosis of the Exhaust Flap Valve N321 is possible. Up to 1,700 rpm the engine is a bit
louder, as the exhaust flap is always open.
-
Faster throttle overrun cutoff, with more direct accelerator pedal and reduced overrun after releasing the accelerator.
-
To prevent the clutch from slipping when accelerating from a stop, the engine torque is slightly reduced when vehicle speed is below 20 mph and
the engine speed is higher than 4600 rpm. There is no noticeable performance difference.
Service
SVM Update Instructions
1. 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:
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.
a. Notify the owner that their ECM or TCM was found to have been tuned.