Engine Controls - ECM Memory Reset After A/T Service

TRANSMISSION & CLUTCH
TC002-03
REVISED

Title:
ECM RESET MEMORY FUNCTION

Models:
'98 - '05 Applicable Models

May 5, 2003

TSIB REVISION NOTICE:
December 20, 2004: Applicable Vehicles section has been updated and modified, 2004 and 2005 model years added; and Reset Procedure 2 has been revised.

Previous versions of this TSIB should be discarded.

Introduction

Whenever an automatic transmission is replaced, overhauled or individual components are replaced, use this procedure to erase Engine Control Module (ECM, SAE term: Powertrain Control Module, PCM) "Learned Values" and minimize subsequent performance concerns.

CAUTION:
Failure to follow the following procedure may lengthen the time to readjust the "Learned Values," potentially resulting in performance concerns.

Applicable Vehicles

Refer to Reset Procedure 1 for the following vehicles with Electronically Controlled Automatic Transmissions:

^ 1999 - 2003 model year ES 300 and RX 300 vehicles.

^ 2003 - 2005 model year GX 470 vehicles.

^ 2004 - 2005 model year RX 330 vehicles.

Refer to Reset Procedure 2 for the following vehicles with Electronically Controlled Automatic Transmissions:

^ 1998 - 2005 model year GS 430/400/300, LS 430/400, LX 470, and SC 430/400/300 vehicles.

^ 2001 - 2005 model year IS 300 vehicles.





Warranty Information





Required SSTs

Reset Procedure 1

1. Connect the Lexus Diagnostic Tester to the vehicle.





2. Reset the ECM (PCM). Refer to the procedures.

3. Start the engine and warm it up to normal operating temperatures before test-driving.

4. Perform a thorough test drive with several accelerations from a stop with "light throttle" application until proper transmission shifting is verified.

Reset Procedure 2

1. Disconnect the negative battery cable for 5 minutes.

2. Reconnect battery cable.

3. Start the engine and warm it up to normal operating temperatures before test-driving.

4. Perform a thorough test drive with several accelerations from a stop with "light throttle" application until proper transmission shifting is verified.