Riviera V6-231 3.8L VIN L SFI (1991)
Shift Solenoid: Customer Interest
A/T - Loss of Drive or Erratic Shifts
Group Ref.: 7 - Transmission
Bulletin No.: 477121
Date: August, 1994
SUBJECT:
INTERMITTENT LOSS OF DRIVE OR ERRATIC SHIFTS
(DIAGNOSIS FOR ELECTRICAL CONDITION)
MODELS:
1991
BUICK REATTA
1991-1993
BUICK RIVIERA
1991-1994
BUICK PARK AVENUE AND REGAL
1992-1994
BUICK LE SABRE
1994
BUICK CENTURY AND SKYLARK
1991-1993
CADILLAC ELDORADO, SEVILLE, SIXTY SPECIAL AND
FLEETWOOD (FWD)
1991-1994
CADILLAC DE VILLE
1991-1994
CHEVROLET LUMINA
1992-1994
CHEVROLET LUMINA APV
1994
CHEVROLET BERETTA AND CORSICA
1991-1992
OLDSMOBILE TORONADO AND TROFEO
1991-1994
OLDSMOBILE NINETY EIGHT AND CUTLASS SUPREME
1992-1994
OLDSMOBILE EIGHTY EIGHT AND SILHOUETTE
1994
OLDSMOBILE CUTLASS CIERA AND ACHIEVA
1991-1994
PONTIAC GRAND PRIX
1992-1994
PONTIAC BONNEVILLE AND TRANS SPORT
1994
PONTIAC GRAND AM
TRANSAXLE APPLICATIONS:
HYDRA-MATIC 4T60-E (RPO M13)
CONDITION:
Some owners may experience one or more of the following intermittent conditions:
^
Loss of drive (neutral condition) on highway while in fourth gear.
^
Erratic upshifts and downshifts at steady throttle angles without a Malfunction Indicator Light (MIL) (Service Engine Soon) illuminated.
^
First and second gear only (no third or fourth gear).
^
First and fourth gear only (no second and third gear).
CAUSE:
These intermittent conditions may be caused by an intermittent short to ground on the "A" or "B" Shift Solenoid wiring between the ECM/PCM and the
transaxle or an internal electrical condition in the transaxle. In most cases, these conditions ARE NOT caused by a hydraulic or mechanical condition in
the transaxle.
CORRECTION:
To diagnose this condition, it will be necessary to perform the following steps that are covered in detail under "Service Information":
1.
Check condition and level of transmission fluid.
2.
Diagnose and repair all ECM/PCM Diagnostic Trouble Codes.
3.
Identify which shift solenoid is being affected.
4.
Determine if cause is internal or external to transaxle.
