Some 2010-2012 Lexus HS250H vehicles equipped with a 2AZ-FXE engine may exhibit a MIL on with DTC P0136 (oxygen sensor circuit malfunction, Bank 1 Sensor 2). The oxygen sensor and hybrid vehicle ECU (HV ECU) logic has been modified to reduce the possibility of this condition occurring. Use the following procedure to address this condition.
CALIBRATION INFORMATION
MODEL YEAR PREVIOUS CAL. NEW CAL.
HS 250H……….2010-2011……..37503000………..… 37503200
Hs250h…………2012……………37508000…………..37508100
PARTS INFORMATION
MODEL YEAR PREV. P/N NEW P/N PART
2010-2011……….89981-75030 89981-75032 HV ECU
89981-75031 89981-75032 HV ECU
2012 ……………..89981-75090 Same HV ECU
All…………..……..89465-75010 Same oxygen sensor
All………………..00451-00001-LBL…...........authorized modifications label
NOTE: The HV ECU should not be replaced as part of the repair procedure.
REQUIRED TOOLS
TIS Techstream, P/N TSPKG1 or TSLITEDLR01
(NOTE: Software version 7.10.030 or later is required)
GR8 battery Diagnostic Station P/N 00002-MCGR8
NOTE: The diagnostic tester is not recommended for flash reprogramming with this calibration file. Please use TIS Techstream or an approved J2534 interface to perform this update. Visit techinfo.Toyota.com for more information regarding J2534 reprogramming.
REPAIR PROCEDURE
- Using TIS Techstream, check for stored DTCs. If only DTC P0136 is present, proceed to Step 2.
- Remove and replace the oxygen sensor (Bank 1, Sensor 2).
- Check for the Authorized Modifications label affixed to the vehicle (underside of LH rear hood area). Confirm if the HV ECU calibration has been updated. If the calibration ID listed is not the latest HV ECU calibration, proceed to Step 4.
- Flash reprogram the HV ECU. Note: The GR8 battery diagnostic station must be used in Power Supply Mode to maintain battery voltage at 13.5 volts while flash reprogramming.
- Test drive to confirm proper operation.
