GENERAL MOTORS issued a recall on the ENVOY and TRAILBLAZER models

Certain sport utility vehicles Trailblazer and GMC Envoy (4 wheel-drive). The calibration of the automatic transfer case control module or a range shift collar that was not machined properly may cause insufficient high speed gear engagement. If the gear is not engaged, the vehicle can roll when the transmission is in "Park" and a crash could result without warning . Correction: Dealers are to perform a "clean neutral" test, as described in the bulletin and if the ratcheting noise is detected during the test, the dealers are to replace the transfer case.