02-20-2007, 07:14 PM
Pardon the newbie questions, but has anyone actually managed to get the 4.2L ('97-'99 - I'm spacing on the code) to work properly without the auto transmission control module? Seems like after scanning the posts some folks have done the 6-speed manual conversion but from everything I've found so far, people are living with the check engine light on. A tuner (No. CA)is telling me that they have encountered a problem with an RPM-related cutout and diminished power too, related to the engine control unit thinking the engine is in "P". I understand that europe (minus the UK) got a manual transmission A8 but I can find no mention of anything but the S8 motor with a manual transmission in ETKA. Is there a code that can be flshed to handle the A8 w/ manual?Thanks so much. Any help is greatly appreciated.
02-21-2007, 04:29 PM
I have a 97' A8 4.2 V8 with a 6 speed manual. I have all the solenoids and sensors plugged into the TCU and there is no CEL. Sorry for the crappy picture.
02-21-2007, 05:35 PM
Is it performing properly according to your butt-dyno? So you left the TCU connected to the ECU and all other transmission sensors (obviously removed from the tranny)? Interesting. I read all your posts with interest, thanks for the info.
02-21-2007, 06:02 PM
Actually it is quicker because of the shorter gear ratio. If I unplug the TCU, it will perform the same way, but it has a CEL after the second ignition cycle. With the TCU connected P or N is fine. In D the TCU influences the ECU too much and ruins the fun of manual transmission. If one of the sensors unplugged in D the engine runs like crap and the it will show limp mode. Deceleration in any lower gear is really bad, it feels like the car is pushing a dead engine. I just keep it in P.
02-26-2007, 06:34 PM
But aren't there speed sensors in the transmission that won't be registering any speed?
02-27-2007, 06:52 PM
The input and output speed sensors in the tranny will call for the shifts and TC lockup. The vehicle speed sensor (speedometer)does not control the TCU. Since the car is in P and there is no signal from the output speed sensor, the TCU doesn't even know the car is moving.
08-25-2007, 07:21 AM
Just to let you know I have met a tuner of the vag ecu's that can re-code the standard ecu's to allow manual transmission without the need of using the tcu etc.