Nissan North America has released information to dealers today detailing upcoming changes to the 2010 Nissan GT-Rs ECU programming which improve acceleration with the VDC setting engaged. Integrated into this change however is a modification to the VDC system which essentially disables the Launch Control function of the car.

This change is also being applied to unsold inventory of 2009 Nissan GT-Rs which are still with dealers but the rumour that Nissan will force this change on current owners turns out to be untrue. Nissan is encouraging current owners to apply the change but will not force them to.

On the upside – Nissan have also made changes a change to the ECU to allow the driver to rev past 2000rpm while at a stop with the VDC on and the brake depressed. This may allow somewhat of a less aggressive launch. We’d have to see some testing to find out exactly what this does. Right now on the 2009 model if you try this you get a very slow take off indeed.

The 2010 GT-R is faster in many ways over the 2009 GT-R in a straight line and around a circuit but it remains to be seen how the US specification 2010 GT-R will fare against the 2009 model in 0-60mph acceleration without launch control.

Personally I think this will cause some controversy but is already blown out of proportion. The number of failed GT-Rs in the US is less than 1% of all cars sold there. That number falls dramatically when you look at the Japanese market which has sold 3 times as many GT-Rs but has less reported transmission failures.

I’m not disappointed at all at the loss of this feature, having tried it out myself, I was not anywhere near as impressed as I was when I first got taken on a circuit in the GT-R by a Nissan test driver … that is what the GT-R is really about.

Full text of the letter to dealers is after the jump.

Dealer Letter Source: Edmunds
Photos: GTRBlog

Nissan has enhanced the Model Year (MY) 2009 GT-R by incorporating new MY 2010 programming that will optimize clutch engagement control for improved drivability. This upgrade also improves vehicle acceleration with the Vehicle Dynamic Control (VDC) ON/activated.

Nissan will provide this MY 2010 specification upgrade to MY 2009 GT-R owners at no additional cost. Nissan has already incorporated this programming into the GT-R vehicles in its U.S. inventory and will resume shipping of those vehicles to dealers. We will advise you soon on how to install this new program into all MY 2009 GT-Rs (see below).

The GT-R will continue to offer supercar characteristics of exceptional handling, maneuvering and overall driving experience. This upgrade provides the consumer improved drivability and enhanced acceleration performance with VDC ON (as required by the warranty). Standing acceleration capability with VDC ON (VDC-R mode) will improve compared to the original model-year 2009 performance while such acceleration with VDC OFF will be moderated. Customers should be reminded to drive safely and obey all traffic laws. [Please note independent media reports of 0-60 drive times with VDC OFF (or what the media call “Launch Control”) on closed-courses with professional drivers will likely increase after this change.]

The GT-R Owner’s Manual expressly warns against driving with the VDC OFF (except to free the vehicle when stuck in mud or snow) to avoid damage. Repeated acceleration launches with VDC OFF have resulted in some reported instances of damage to the transaxle. Repairs for damage caused by driving with VDC OFF are expressly excluded under the terms of the Nissan GT-R New Car Limited Warranty… Except when stuck, there is no reason to drive with VDC OFF.

This change was initially implemented with the start of MY 2010 GT-R production and has been completed for all 2009 GT-Rs still in NNA inventory… In a few weeks, you will receive the Technical Service Bulletin explaining how to implement this specification change for all remaining 2009 GT-Rs…