Lebaron GTS L4-153 2.5L SOHC Turbo VIN J FI (1989)
Control Module: Customer Interest
A/T - A604 Excessive Upshifting/Downshifting
Models
1989-90 AA, AC, AG, AJ, AS, & AY Bodies
Subject
A-604 Transmission Excessive Upshifting/ Downshifting
Index
TRANSMISSION
Date
April 9, 1990
No.
21-12-90
(C21-06-0)
P-1042
BODY CODE LEGEND
AA - ACCLAIM/SPIRIT/LEBARON
AC - DYNASTY/NEW YORKER LANDAU/SALON
AG - DAYTONA
AJ
- LEBARON COUPE/LEBARON CONVERTIBLE
AS - CARAVAN/GRAND CARAVAN/CARAVAN C/V
VOYAGER/GRAND VOYAGER/TOWN & COUNTRY
AY -
IMPERIAL/NEW YORKER FIFTH AVENUE
SYMPTOM/CONDITION
Some owners may complain of a transmission upshift/downshift hunting (3-4 busyness) condition when the vehicle is fully loaded, driving up a grade or
into a head wind.
This condition can occur on vehicles equipped with the A-604 controller PN 4557120 or prior (1989) model year A-604 controllers.
A new A-604 controller, PN 4557585, entered production late March 1990. The new controller allows the torque converter to unlock, instead of
initiating a 4-3 downshift during slight vehicle torque load changes.
DIAGNOSIS
Check the A-604 controller part number, if the PN is 4557585, this Technical Service Bulletin does not apply.
Connect the DRB II and perform the diagnostic test as outlined in the appropriate Powertrain Diagnostic Procedure Manual.
If no fault codes are present, perform the following repair procedure.
If fault codes are present, they must be corrected and the corrections verified before performing the following repair procedure.
PARTS REQUIRED
1.
1 - Controller PN 4557585
REPAIR PROCEDURE
This repair involves the replacement of the transaxle controller.
1.
Disconnect the negative battery cable.
2.
Disconnect the 60-way connector from the controller.