A/T - In Third Gear When 3-2 Downshift Is Desired: Overview

Bulletin No.: 93-58
File in Group: 17
Number: 252
Corp.Ref.No.: 277152R
Date: March, 1993

SUBJECT:
TRANSAXLE REMAINS IN THIRD GEAR WHEN 3-2 DOWNSHIFT IS DESIRED (CODE P029) OR REMAINS IN SECOND GEAR

MODELS AFFECTED:
1993 ELDORADOS, SEVILLES, AND ALLANTES WITH HYDRA-MATIC 4T80-E (RPO MH1)

Some 1993 Eldorados, Sevilles, and Allantes equipped with the Hydra-Matic 4T80-E (RPO MH1) transaxle built on or before Julian Date 318 (November 14, 1991) may remain in third gear when a 3-2 downshift is desired or remain in second gear when a 2-3 upshift is desired. A code P029 maybe set by the PCM due to the no 3-2 downshift-condition.

This condition may be caused by the 2-3 valve train (907, 908) in the lower control valve assembly (903) which has a valve interlock feature. Some valves may have been manufactured with the interlock misaligned causing the 3-2 valve train to bind in the valve body bore.