Introduction
This bulletin addresses a common issue in select Toyota models where the Malfunction Indicator Lamp (MIL) illuminates due to Diagnostic Trouble Code (DTC) P0138. This code indicates an "A/F Sensor Stuck Lean" condition, specifically related to the Oxygen Sensor Circuit High Voltage on Bank 1 Sensor 2. The affected vehicles include the 2009-2012 model year Toyota RAV4 and the 2010-2011 model year Toyota Camry, both equipped with the 2AR-FE engine (excluding PZEV variants). The condition may stem from an inaccurate air-fuel ratio sensor response. Toyota has issued a software update for the Engine Control Module (ECM) to mitigate this issue. This document outlines the diagnostic steps and repair procedures necessary to resolve this problem.
Applicability
This service bulletin applies to the following Toyota models:
- 2010-2011 Camry (WMI: 4T1, JTN; VDS: BF3EK; Engine: 2AR; Transmission: MANUAL, AUTOMATIC)
- 2009-2012 RAV4 (WMI: 2T3, JTM; VDS: BF31V, BF32V, BF33V, BF34V, BF35V, BF4DV, BF9DV, DF4DV, DF9DV, EF4DV, JF4DV, KF4DV, KF9DV, RF4DV, WF4DV, XF4DV, YF4DV, YF9DV, ZF31V, ZF32V, ZF33V, ZF34V, ZF35V, ZF4DV, ZF9DV; Engine: 2AR; Drive Type: 4WD, 2WD; Transmission: AUTOMATIC)
Note: This bulletin is not applicable to Partial Zero Emission Vehicles (PZEV).
Repair Procedure Overview
The recommended repair procedure involves verifying the presence of DTC P0138, performing an active test on the A/F sensor using Toyota's Techstream diagnostic tool, and comparing the sensor's voltage output to specified values. If the diagnosis confirms the issue, the ECM (PCM) calibration will need to be updated. The procedure also details the use of specific service tools and the application of an Authorized Modifications Label after the repair.
Key steps include:
- Checking for exhaust leaks.
- Verifying DTC P0138 using Techstream.
- Performing an active test on the A/F sensor to monitor voltage.
- Comparing monitored voltages against the guidelines in Table 1.
- Checking for and confirming the latest ECM (PCM) calibration via the Authorized Modifications Label.
- Flash reprogramming the ECM (PCM) with the new calibration file.
- Preparing and installing the Authorized Modifications Label with relevant information.
- Replacing the A/F sensor if necessary, following the specific removal/installation procedures outlined in the respective model's Repair Manual.
- Clearing all DTCs using Techstream.
- Test-driving the vehicle to confirm the repair and ensure no DTCs are present.
For detailed instructions on using specialized equipment like the GR8 Battery Diagnostic Station, refer to the GR8 Instruction Manual available on TIS.
Parts and Tools Information
The following parts and tools are referenced in this bulletin:
- Parts: Air Fuel Ratio Sensor, Computer Engine Control (ECM/PCM), Authorized Modifications Labels. Specific part numbers are provided for different models.
- Tools: Techstream (2.0 or Lite), GR8 Battery Diagnostic Station.
For more information on J2534 reprogramming, visit techinfo.toyota.com.
