General Motors Eliminates Delta P Relearn
For many years it has been possible to relearn the TPMS on a GM vehicle by simply changing the pressure in the tires either up or down. It has come to the Attention of CTI that Gm has changed the programming of the TPMS and will no longer allow relearn using a change in tire pressure (Delta P). CTI has been in contact with our partners at Schrader Electronics and has received confirmation of this change. GM has advised that this change in programming was necessary to combat sensor cross-talk issues which are occurring more frequently in dealer service departments.
What does this mean for the aftermarket technician? The quick way to relearn GM TPMS without a tool will not work on newer GM vehicles. No firm production date can be found for the software change, other than to say that the change occurred in late 2011 affecting MY 2012 GM vehicles. This means, however, that there are some early production 2012 vehicles which may still have the ability to use Delta P relearn. However, the best way to proceed is to figure on any GM 2012 or newer a TPMS relearn too should be used to activate the TPMS sensors.
GM has a new special tool for dealerships which will activate the sensors, Kent-Moore part EL-50448. Where tools are concerned, these GM software changes will have no effect as current TPMS tools will continue to function as an activation device for these systems.