Cutlass Supreme FWD V6-189 3.1L (1989)
Torque Converter Clutch: Technical Service Bulletins
Engine Controls - Revised Charts C-8A & C-8C, TCC
SUBJECT:
SERVICE MANUAL UPDATE - SECTION 6E - DRIVEABILITY AND EMISSIONS - REVISED CHARTS C-8A, C-8C
MODELS/YEARS:
1988-89 CUTLASS SUPREME MODELS EQUIPPED
WITH 2.8L, 3.1L (VIN CODE T, W)
NUMBER:
89-T-41
CORP. REF. NO: 916503
DATE:
February 1989
SECTION:
6E
This bulletin revises the Facing Page and Chart for C-8A (Page 1 of 2) and C-8C (Page 1 of 3) Torque Converter Clutch (TCC) Electrical Diagnosis in
Section 6E "Driveability And Emissions" of the 1988-89 Service Manual for the Cutlass Supreme Carline with 2.8L LB6 (VIN W) and 3.1L LH0 (VIN
T) V6 engines. Terminal "F" of the ALDL for TCC has been deleted. The revised diagnostic procedure is attached.
CHART C-8A
(Page 1 of 2)
440-T4 TORQUE CONVERTER CLUTCH (TCC) (ELECTRICAL DIAGNOSIS)
Circuit Description:
2.8L (VIN W) "W" CARLINE (PORT) The purpose of the automatic transmission torque converter
clutch feature is to eliminate the power loss of the torque converter stage when the vehicle is in a cruise
condition. This allows the convenience of the automatic transmission and the fuel economy of a manual
transmission. The heart of the system is a solenoid located inside the automatic transmission which is
controlled by the ECM. When the solenoid coil is activated ("ON"), the torque converter clutch is
applied which results in straight through mechanical coupling from the engine to transmission. When the
transmission solenoid is deactivated, the torque converter clutch is released which allows the torque
converter to operate in the conventional manner (fluidic coupling between engine and transmission). The
TCC will engage on a warm engine under given road load in 3rd and 4th gears. TCC will engage when:
^
Engine warmed up
^
Vehicle speed above a calibrated value (about 28 mph 45 km/h)
^
Throttle position sensor output not changing, indicating a steady road speed
^
Brake switch closed
