BUICK/CADILLAC/CHEVROLET/GMC: EQUIPPED WITH 6T70 OR 6T75 AUTOMATIC TRANSMISSION (RPOS MH2, MH4, MH6, MY9). TRANSMISSIONS BUILT 4/1/10 THRU 5/8/10. A HARSH SHIFT, TYPICALLY INTO THIRD OR FIFTH GEAR. UPON INVESTIGATION, TECHNICIAN MAY FIND DTC P0843 IN THE TCM AS A HISTORY OR ACTIVE DTC. MODELS ENCLAVE, LACROSSE, SRX, EQUINOX, TRAVERSE, ACADIA AND TERRAIN. *PE UPDATED 3/28/11. *PE