Some vehicles may experience the check engine light and automatic transaxle warning light ON with one or more of these DTCs stored in the TCM memory (P0842, P0847, P0872, P0877, P0780, P1738). P0842:00 - Oil pressure switch No. 1 (oil pressure switch B) stuck on P0847:00 - Oil pressure switch No. 2 (oil pressure switch A) stuck on P0872:00 - Oil pressure switch No. 3 (oil pressure switch A) stuck on P0877:00 - Oil pressure switch No. 4 (oil pressure switch B) stuck on P0780:00 - Gear shifting malfunction P1738:00 Automatic transaxle internal malfunction This is caused by the oil pressure switch A and/or B at the control valve body temporarily or permanently getting stuck due to contamination entering the passage. To correct the problem, some mass production changes have been implemented to reduce contamination and improve the DTC diagnostic logic. NOTE: If the vehicle also has a delayed engagement concern, this TSB is not applicable. Refer to MGSS online for proper diagnosis and repair procedure.
