Staff member
Please see T-SB-0056-22 (link needed)


Some 2021 model year RAV4 Prime vehicles may exhibit a depleted 12V auxiliary battery when in IG-OFF due to a condition in which the Hybrid Vehicle Electronic Control Unit (HV ECU) does not sleep. The HV ECU may not sleep if any of the following conditions have occurred with the vehicle:

* The vehicle was towed or jump-started after a 12V battery discharge.
* The vehicle’s 12V battery was disconnected and reconnected, as when accessories were installed.
* The 12V battery terminal(s) or power or ground harnesses were removed to repair the vehicle.
* A new 12V battery was put into the vehicle, or there was an open in the main fusible link.
* Any other condition that may have caused power not properly flowing from the 12V battery through the harness.

The HV ECU logic has been updated to reduce the possibility of this condition. Follow the Repair Procedure in this bulletin to address this condition.


* This repair is covered under the Toyota Hybrid 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 occurrence of the specified condition described in this bulletin.

* 2021 model year RAV4 Prime vehicles that are registered and normally operated in California, Arizona (2012 model year only), Connecticut (starting with 2005 model year), Maine (starting with 2004 model year), Maryland (starting with 2011 model year), Massachusetts (starting with 2004 model year), New Hampshire (2005 – 2009 model year only), New Jersey (starting with 2005 model year), New Mexico (2010 – 2011 model year only), New York (beginning with 2004 model year with Zero Emissions (ZE) models only; all models starting with 2016 model year), Oregon (starting with 2008 model year), Rhode Island (starting with 2005 model year), and Vermont (starting with 2004 model year) – Partial Zero Emission Vehicle (PZEV) Emission Warranty Coverage is in effect for 15 years or 150,000 miles, from the vehicle’s in-service date, whichever occurs first. (Please reference Warranty Policy Bulletin POL14-09 for additional information)

* Four additional states (Delaware [beginning with 2014 model year], Colorado [starting 2022 model year], Pennsylvania [beginning with 2008 model year], and Washington [beginning with 2009 model year]) have adopted the California Emission Warranty. However, in these states, performance and long-term defect warranty coverage is 7 years or 70,000 miles, whichever occurs first.


Repair Procedure:
1. Has the vehicle exhibited a depleted 12V auxiliary battery?
YES — Continue to step
NO — This bulletin does NOT apply. Continue diagnosis using the applicable Repair Manual.

2. Use Techstream to confirm if the HV ECU calibration has been updated and check for the Authorized Modifications Label affixed to the vehicle in the location shown below. Is the calibration ID listed in Techstream and on the label the latest HV ECU calibration?
YES — This bulletin does NOT apply. Continue diagnosis using the applicable Repair Manual.
NO — Continue to step 3.

3. Flash reprogram the HV ECU.

4. Prepare and install the Authorized Modifications Label.

5. Test-drive the vehicle to confirm proper operation