Engine, A/T Controls - Harsh 2-1 Downshift On Acceleration

T-SB-0237-12

December 7, 2012

ECM Calibration: Enhancement to Shifting Performance

Service Category
Drivetrain

Section
Automatic Transmission/Transaxle

Market
USA





Applicability

Introduction

Some 2008 - 2011 model year Land Cruiser vehicles may exhibit a harsh shift on acceleration below 20 mph during the 2-1 downshift. The Engine Control Module/ECM (SAE term: Powertrain Control Module/PCM) calibration has been revised. Use the following repair procedure to address this condition.





Warranty Information





Parts Information





Calibration Information








Required Tools & Equipment

Repair Procedure

1. Test drive the vehicle and confirm there is a harsh shift on acceleration below 20 mph.

NOTE

Confirm correct transmission fluid level by following the procedures in the Repair Manual BEFORE reprogramming the ECM (PCM) since incorrect fluid level can also cause shifting issues.





2. Check for the Authorized Modifications Label affixed to the vehicle in the location shown in Figure 1. Confirm if the ECM (PCM) calibration has been updated. If the calibration ID listed is NOT the latest ECM (PCM) calibration - go to step 3.

3. Flash reprogram the ECM (PCM).

NOTE

^ The GR8 Battery Diagnostic Station MUST be used in Power Supply Mode to maintain battery voltage at 13.5 volts while flash reprogramming the vehicle.

^ For details on how to use the GR8 Battery Diagnostic Station, refer to the GR8 Instruction Manual located on the Technical Information System (TIS), Diagnostics - Tools & Equipment - Battery Diagnostics.

Follow the procedures outlined in Service Bulletin"Techstream ECU Flash Reprogramming Procedure", and flash the ECM (PCM) with the NEW calibration file update.

4. Install the Authorized Modifications Label.

A. Using a permanent marker enter the following information on the label:

^ ECM part number [Refer to the Parts Information section for the CURRENT PART NUMBER]

^ Calibration ID(s) [Refer to the Calibration Identification Chart for the NEW CALIBRATION ID]

^ Dealer Code

^ Repair Date

^ Change Authority [This bulletin number]

B. Affix the Authorized Modifications Label to the vehicle at the location shown in Figure 1. The Authorized Modifications Label is available through the MDC P/N 00451-00001-LBL.

5. Test drive the vehicle and perform transmission initialization.

Refer to TIS applicable model and model year Repair Manual:

2008 / 2009 / 2010 / 2011 Land Cruiser:
Drivetrain - Automatic Transmission/Transaxle - "AB60F Automatic Transmission/Transaxle: Automatic Transmission System: Initialization"

© 2012 Lexus, a division of Toyota Motor Sales, USA