Sonata GL V6-3.0L (1997)
Engine Control Module: All Technical Service Bulletins
A/T - Mutual Control Introduction
Group: TRANSAXLE
Number: 97-40-001-1
Date: JULY, 1997
Model: ALL
Subject:
AUTOMATIC TRANSAXLE MUTUAL CONTROL
This TSB supersedes TSB # 97-40-001 to correct the TCM part numbers and effective vehicle production dates.
DESCRIPTION:
Mutual control has been introduced on 1997 model automatic transaxles to improve shift quality. Mutual control allows communication between the
Powertrain Control Module (PCM) and Transaxle Control Module (TCM) to retard engine timing during shifting. As a result, engine torque is
temporarily reduced during shifting, which results in improved shift feeling and clutch durability.
As the timing is restored after an upshift is completed, a feeling of slightly increased power may occasionally be noticed. Experienced service personnel
may be more likely to notice the difference in shift feeling compared to 1996 and earlier vehicles. Some customers may incorrectly perceive this surge as
a slipping shift; however, this is normal operation of the mutual control.
ANALYSIS:
Mutual control is possible only when the following four (4) conditions are simultaneously met:
1.
Battery voltage above 10 V
2.
TPS above 1.2 V
3.
ATF temperature above 45°C (113°F) or transaxle output speed (pulse generator B) above 1487 rpm for 10 minutes
4.
Engine speed above 1500 rpm
Engine timing for Bosch controllers is retarded according to engine speed as shown. 1997 Sonata vehicles use Melco controllers, which have slightly
different retard specifications.
For additional information regarding the torque reduction signal from the TCM to the PCM, refer to the 1997 Sonata Shop Manual, Volume 2, page
SD-83 and the 1997 Tiburon Shop Manual, Volume 2, page SD-58.
EFFECTIVE VEHICLE PRODUCTION DATE:
Model
Production Date
1997 Accent
September 1, 1996
1997 Elantra Sedan & Wagon
July 7, 1996
1997 Sonata 2.0L & 3.0L
July 1, 1996
