Engine Controls - MIL ON/DTC's P0731/P0732 Set
L-SB-0009-09February 5, 2009
M.I.L. "ON" DTC P0731/P0732
Service Category
Drivetrain
Section
Hybrid Transmission/Transaxle
Market
USA
Applicability
Introduction
Some vehicles may exhibit a M.I.L. "ON" condition with one or more of the following Diagnostic Trouble Codes (DTCs):
^ P0731 - Gear 1 Incorrect Ratio
^ P0732 - Gear 2 Incorrect Ratio
The HV ECU logic and transmission pressure switches have been updated to correct these conditions. Follow the repair procedure in this bulletin to address customer concerns.
The DTC will determine which pressure switch will be replaced:
^ P0731 will be corrected by oil pressure switch No.2 (PB2) replacement.
^ P0732 will be corrected by oil pressure switch No.1 (PBI) replacement.
Production Change Information
This TSIB applies to vehicles produced BEFORE the Production Change Effective VINs shown.
Warranty Information
^ Op Code TC8011: This repair is covered under the Lexus Comprehensive Warranty. This warranty is in effect for 48 months or 50,000 miles, whichever occurs first, from the vehicle's in-service date.
^ Op Codes EG8059 & EG8060: This repair is covered under the Hybrid System Warranty. This warranty is in effect for 96 months or 100,000 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
^ The HV ECU 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
1. Remove the No.2 engine under cover.
2. Drain the transmission fluid.
A. Remove the drain plug and gasket and drain the ATF.
B. Install a new gasket and the drain plug.
Torque: 20 N*m (204 kgf*cm, 15 ft*lbf)
3. Remove the transmission oil pan sub-assembly.
A. Remove the 6 bolts oil pan and gasket from the transmission.
B. Remove the transmission oil cleaner magnets from the oil pan.
^ 2 magnets for all LS 600h vehicles and for earlier production GS 450h vehicles (produced September - October 2007).
^ 4 magnets for later production GS 450h vehicles (produced November 2007 and later).
C. Collect any steel chips with the oil cleaner magnets. Carefully look at the foreign objects and particles in the pan and on the magnets to determine the type of wear found in the transmission.
^ Steel (magnetic): bearing gear and clutch plate wear.
^ Brass (non-magnetic): bushing wear.
4. Remove the oil strainer assembly.
A. Remove the 3 bolts and oil strainer from the valve body.
B. Remove the 0-ring from the oil strainer.
5. Remove the related oil pressure switch.
NOTE
Remove oil pressure switch No.1 (PBI) for DTC P0732 and remove oil pressure switch No.2 (PB2) for DTC P0731.
A. Disconnect the oil pressure switch connector.
NOTICE
When disconnecting the oil pressure switch connector; do NOT bend the terminals.
B. Remove the oil pressure switch from the valve body.
6. Install the NEW oil pressure switch.
A. Install the oil pressure switch to the valve body.
Torque: 4.4 N*m (45 kgf*cm, 39 in*lbf)
HINT
Oil pressure switches PBI and PB2 are marked with blue paint.
B. Connect the oil pressure switch connector.
7. Reinstall the oil strainer assembly.
A. Coat a new 0-ring with ATF and install it to the oil strainer.
B. Install the oil strainer to the valve body with the 3 bolts.
Torque: 10 N*m (102 kgf*cm, 7 ft*lbf)
NOTICE
^ Do NOT allow the wire harness to get caught between the parts.
^ Make sure that the 0-ring is NOT twisted.
^ Do NOT allow the 0-ring to get jammed between the parts.
8. Install the transmission oil pan sub-assembly.
A. Clean and install the magnets in the oil pan.
^ All LS 600h vehicles and earlier production GS 450h vehicles (produced Sept. - Oct. 2007) have 2 magnets in the oil pan.
^ Later production GS 450h vehicles (produced Nov. 2007 and later) have 4 magnets in the oil pan.
B. Install a new gasket to the oil pan.
NOTICE
^ Make sure that there is NO oil or foreign matter on the gasket seal surface or oil pan contact surface.
^ Install the gasket so that there is NO slack in the gasket, and the entire circumference of the seal surface is level.
^ Make sure that the 6 gasket drop prevention protrusions are set on the oil pan.
^ When tightening the oil pan, make sure that the gasket is NOT pinched between the gasket tightening area sleeve and the transmission seal surface.
C. Install the oil pan to the transmission case with the 6 bolts.
Torque: 7.5 N*m (76 kgf*cm, 66 in*lbf)
9. Add transmission fluid.
Refer to the Technical Information System (TIS) applicable model and model year Repair Manual:
^ 2007 or 2008 GS 450h Drivetrain - Hybrid Transmission/Transaxle - "L110 Hybrid Transmission/Transaxle: Hybrid Transmission Fluid: Adjustment"
^ 2008 LS 600h Drivetrain - Hybrid Transmission/Transaxle - "L110F Hybrid Transmission/Transaxle: Hybrid Transmission Fluid: Adjustment"
10. Install the No 2. engine under cover.
11. Pressurize the fluid system.
Turn the power switch "ON" and "OFF" twice. DTCs for the oil pressure switch may be output while performing this procedure, but they do NOT indicate malfunctions.
12. Clear any DTCs that are created during this procedure.
13. Check for the Authorized Modifications Label.
Check for the label affixed to the vehicle in the location shown in Figure 19. Confirm if the HV ECU calibration has been updated. If the calibration ID listed is NOT the latest HV ECU calibration - go to step 14.
14. Flash Reprogram the HV ECU.
^ 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 TSIB No.SS002-07, "Techstream ECU Flash Reprogramming Procedure", and flash the ECM (PCM) with the NEW calibration file update.
15. Install the Authorized Modifications Label.
A. Using a permanent marker, enter the following information on the label:
^ HV ECU 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 TSIB number]
B. Affix the Authorized Modifications Label to the vehicle at the location shown in Figure 18. The Authorized Modifications Label is available through the MDC, P/N 00451-00001-LBL.
16. Perform "Reset Memory".
Refer to TIS, applicable model and model year Repair Manual:
^ 2007 or 2008 GS 450h, Drivetrain - Hybrid Transmission/Transaxle - "L110 Hybrid Transmission/Transaxle: Hybrid Transmission System: Initialization"
^ LS 600h, Drivetrain - Hybrid Transmission/Transaxle - "L110 Hybrid Transmission/Transaxle: Hybrid Transmission System: Initialization"
17. Start the engine and warm it up to normal operating temperature before test driving.
18. Test drive the vehicle to confirm proper vehicle operation.