Engine, A/T Controls - Harsh Downshift When Stopping
T-SB-0082-09March 11, 2009
Harsh Downshift When Coming to a Stop
Service Category
Drivetrain
Section
Automatic Transmission/Transaxle
Market
USA
Applicability
Introduction
Some customers may experience a harsh downshift feeling when coming to a stop after the transaxle has up-shifted to 4th or 5th gear. The Engine Control Module/ECM (SAE term: Powertrain Control Module/PCM) calibration has been revised. Use the following repair procedure to address customer concerns.
Warranty Information
^ This repair is covered under the Toyota Federal Emission Warranty. This warranty is in effect for 96 months or 80,000 miles, whichever occurs first, from the vehicle's in-service date.
^ Warranty application is limited to correction of a problem based upon a customer's specific complaint.
Parts Information
^ The ECM (PCM) should NOT be replaced as part of the repair procedure.
^ Authorized Modification Labels may be ordered in packages of 25 from the Materials Distribution Center (MDC) through Dealer Daily - Dealer Support Materials Orders.
Calibration Information
Required Tools & Equipment
^ Additional SSTs may be ordered by calling 1-800-933-8335.
^ The GR8 Battery Diagnostic Station (P/N 00002-MCGR8) supersedes the Automatic Trickle Charger (P/N 00002-YA122-01) and Fast Battery Chargers (Associated P/N ASE6003 and Christie P/N CAPPDQ). P/N 00002-YA122-01, ASE6003, and CAPPDQ are now obsolete.
Repair Procedure
1. 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 2.
2. 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 located on the Technical Information System (TIS), Diagnostics - Battery
Follow the procedures outlined in TSB No. SS002-07, "Techstream ECU Flash Reprogramming Procedure", and flash the ECM (PCM) with the NEW calibration file update.
3. Reset the engine and ECT memory.
Refer to TIS applicable model and model year Repair Manual:
2009 Corolla / Matrix:
Drivetrain - Automatic Transmission/Transaxle - "U250E Automatic Transmission / Transaxle: Automatic Transaxle System: Initialization"
4. Start the engine and warm it up to normal operating temperature before test driving.
5. Test drive the vehicle to confirm proper vehicle operation and ECM (PCM) initial learning.
NOTE
During the initial test drive there may be some slightly harsh downshifts - these are NORMAL. They are a result of fuel cut control. Continue test driving until initial learning and smooth shifting are achieved.
Refer to TIS applicable model and model year Repair Manual:
2009 Corolla / Matrix:
Drivetrain - Automatic Transmission/Transaxle - "U250E Automatic Transmission/Transaxle: Automatic Transaxle System: Road Test"
6. Install the Authorized Modifications Label.
A. Using a permanent marker enter the following information on the label:
^ ECM part number [Refer to the Parts In formation 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 TSB 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.