Engine/A/T Controls - Downshift Lag/Gear Hunting
TRANSMISSION & CLUTCHTC005-03
REVISED
Title:
ECM CALIBRATION: SHIFT FEELING
ENHANCEMENT
Models:
'04 - '05 RX 330
August 11, 2003
REVISION NOTICE:
^ May 20, 2005: The following changes have been implemented since first publication: 2005 model year RX 330 vehicles added to Applicable Vehicles. Introduction and Note updated on page 1. New part, Brake Actuator Assembly, added. Calibration Identification Chart updated to include 2005 model year RX 330 calibration IDs. Repair Procedure expanded with instructions for vehicles with laser cruise control.
Previous versions of this TSIB should be discarded.
Introduction
To improve the transmission shift feeling during specific operating modes, the Engine Control Module (ECM) (SAE term: Powertrain Control Module/PCM) calibration has been revised. These improvements include:
^ Reduced downshift lag when accelerating at speeds from 10 to 20 mph.
^ Less gear hunting when driving on/off accelerator pedal at 20 to 30 mph (for example: during heavy rush-hour traffic).
^ Improved response rate during heavy acceleration from a stop.
NOTE:
^ Version 12.la or later Diagnostic Tester software is required to perform this procedure.
^ Before proceeding, verify the ECM (PCM) calibration has NOT been updated by checking for the Authorized Modifications Label (shown in step 1 of the Repair Procedure).
^ Harsh ATM shifting may result if any Repair Procedure steps are omitted (specifically steps 5 and 11).
Applicable Vehicles
^ 2004 - 2005 model year RX 330 vehicles.
Warranty Information
Applicable Warranty*:
This repair is covered under the Lexus Federal Emissions 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
NOTE:
Authorized Modification Labels may be ordered in packages of 25 from the Materials Distribution Center (MDC) through Dealer Daily Dealer Support Materials System or by calling the MDC at 1-800-622-2033.
Required SSTs
Calibration Identification Chart
Repair Procedure
1. Check for the Authorized Modifications Label affixed to the vehicle in the location shown in Figure 1. Confirm if ECM (PCM) calibration has been updated. If not the latest ECM (PCM) calibration go to step 2.
2. Connect the Diagnostic Tester to the vehicle and select CURRENT ECU CAL from the ECU REPROGRAM MAIN MENU. Determine the vehicle's current ECU calibration (see Figure 2).
- The sample screen prints seen below are the 12.1 a software version and may differ from subsequent software versions.
NOTE:
^ If Calibration ID matches "Previous Calibration ID" as shown in Calibration Identification Chart, proceed with flash reprogramming.
^ If Calibration ID matches "New Calibration ID" as shown in Calibration Identification Chart, this vehicle has already been programmed. Refer to TIS for diagnostic procedures applicable to any stored DTCs.
3. If ECU calibration ID is not the same as the "New Calibration ID" listed previously, proceed to Flash Reprogram ECM (PCM).
4. Flash Reprogram ECM (PCM)
Follow the procedures outlined in Lexus TSIB No. SS001-01, "ECU Flash Reprogramming Process," and flash the ECM (PCM) with the new calibration file update.
NOTE:
If the "Check Engine" light is ON when the ignition is turned back on to begin the reprogramming process, a scan tool cable problem exists. Refer to TSIB No. SS003-O1, "ECU Flash Reprogramming Error Message."
5. Reset the ECM (PCM) learned values using the Diagnostic Tester. Refer to the procedures below.
- The sample screen prints seen below are the 12.1 a software version and may differ from subsequent software versions.
NOTE:
Failure to reset the ECM (PCM) memory will result in continued ATM shifting complaints.
6. Follow the procedures outlined in TSIB No. EG012-04, "Entering VIN During ECM (PCM) Replacement and/or DTC P0630," and write the VIN to the ECM (PCM).
7. For vehicles NOT equipped with laser cruise control, proceed to step 10.
8. For vehicles equipped with laser cruise control, a new Brake Actuator Assembly (with VSC ECU) must be installed at the time of recalibration. If vehicle is equipped with laser cruise control, use the Parts Information table to order the correct part (2WD or 4WD) and follow the instructions listed on TIS: 2004 model year RX 330 Repair Manual: Brake: ABS & Traction Actuator Assy: Replacement to replace the Brake Actuator Assembly (with VSC ECU).
9. Follow the procedures outlined in TSIB No. BR001-04, "Zero Point Calibration," to calibrate the sensors affected by the Brake Actuator Assembly replacement.
10. Start the engine and warm it up to normal operating temperature before test-driving.
11. Test-drive vehicle to confirm proper vehicle operation (and proper laser cruise control operation if so equipped).
12. Enter the required information on the Authorized Modifications Label and affix it to the vehicle at the location shown in Figure 1. The Authorized Modifications Label is available through the MDC, P/N 00451-00001-LBL.
13. Calibration update is complete.
NOTE:
^ Select premium unleaded gasoline with an Octane Rating of 91 or higher for optimum engine performance.
^ The effect of the new calibration may become more apparent after several days of driving as the ECM (PCM) "learned values" are re-established from the customer's driving.