Automatic Transaxle Mutual Control (97-40-001-1)

WARNING: This page is about the Tiburon Base, Automatic, which is a different variant/trim than selected.

Publication date: 1997-08-01
Reference number: 97-40-001-1
Supersedes refnos: 97-40-001

AUTOMATIC TRANSAXLE MUTUAL CONTROL

TECHNICAL SERVICE BULLETIN

Reference Number(s): 97-40-001-1, Date of Issue: August, 1997

HYUNDAI:	Accent 1997, Elantra 1997, Sonata 1997 and Tiburon 1997
GROUP:	40 - Transaxle

NOTE: 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:

Battery voltage above 10 V
TPS above 1.2 V
ATF temperature above 45°C (113°F) or transaxle output speed (pulse generator B) above 1487 rpm for 10 minutes
Engine speed above 1500 rpm

Engine timing for Bosch controllers is retarded according to engine speed as shown below. 1997 Sonata vehicles use Melco controllers, which have slightly different retard specifications.

ENGINE RETARD SPECIFICATIONS

	Engine RPM	2000	2000	3120	3720
UPSHIFT	Retard (deg.)	3	2.25	0.75	0
	Engine RPM	2120	3200	4320	5400
DOWNSHIFT*	Retard (deg.)	1.5	0.75	0	0
Note: No mutual control occurs during the 2-1 downshift.

For additional information regarding the torque reduction signal from the TCM to the ECM, 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 And Wagon	July 7, 1996
1997 Sonata 2.0L And 3.0L	July 1, 1996
1997 Tiburon 1.8L And 2.0L	June 1, 1996

PARTS INFORMATION

MODEL	PART NUMBER PCM	PART NUMBER TCM
1997 Sonata 2.0L (CAL)	39110-33395	95440-32955
1997 Sonata 2.0L (FED)	39110-33365	95440-32955
1997 Sonata 3.0L	39110-35360	95440-38635
1997 Tiburon 1.8L	39150-23920	95440-28328
1997 Tiburon 2.0L	39110-23910	95440-28328
1997 Elantra Sedan And Wagon	39110-23920	95440-28328
1997 Accent (CAL)	39110-22355	95440-22666
1997 Accent (FED)	39110-22350	95440-22666

INTERCHANGEABILITY

Powertrain Control Module: N

Old-->New=NO, New-->Old=NO

Transaxle Control Module: N

Old-->New=NO, New-->Old=NO