Engine Controls - MIL ON/DTC's P0031/P2238 Set
ENGINEEG032-04
Title:
M.I.L. "ON" DTC P0031 AND/OR P2238
Models:
'04 Highlander (2AZ-FE)
August 23, 2004
Introduction
Under certain driving conditions, some 2004 model year Highlander vehicles with 2AZ-FE engines may exhibit a M.I.L. ON" condition with one or both of the following DTC's.
^ P0031 - Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1)
^ P2238 - Oxygen Sensor Pumping Current Circuit Low (For A/F Sensor) (Bank 1 Sensor 1)
The A/F sensor manufacturing process and the Engine Control Module (ECM) (SAE term:
Powertrain Control Module/PCM) logic have been modified to improve these conditions.
CAUTION:
Version 11.0a or later Diagnostic Tester software is required.
Applicable Vehicles
^ 2004 model year Highlander vehicles equipped with 2AZ-FE engines produced BEFORE the Production Change Effective VINs shown below.
Production Change Information
Warranty Information
Applicable Warranty*:
This repair is covered under the Toyota Specified Major Emission Control Component 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.
Required SSTs
Calibration Information
Repair Procedure
For DTC P0031 and/or P2238
1. Replace Bank 1 Sensor 1 A/F Sensor.
2. Perform ECM (PCM) recalibration (see Calibration Procedure) with New Calibration ID as shown above in Calibration Information table.
Calibration Procedure
Verify Vehicle Condition
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's DLC3 connector and select CURRENT ECU CAL from the ECU REPROGRAM MAIN MENU. Determine the vehicle's current ECU calibration (see Figure 2).
NOTE:
^ If Calibration ID matches "Current Calibration ID" as shown, proceed with flash reprogramming.
^ If Calibration ID matches "New Calibration ID" as shown, this vehicle has already been reprogrammed. Refer to Repair Manual or TIS for diagnosis.
3. If ECU calibration ID is not the same as the "New Calibration ID" listed previously, proceed to Flash Reprogram ECM (PCM).
Flash Reprogram ECM (PCM)
1. Follow the procedures outlined in TSB No. SS002-01, "ECU Flash Reprogramming Process," and flash the ECM (PCM) with new calibration file update.
2. 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.
3. Calibration update is complete.