California Air Resources Board

Last updated October 13, 2022.

The public may use the Public Transport Refrigeration Unit (TRU) Search to search the Air Resources Board Equipment Registration (ARBER) system to check the compliance status of TRUs and TRU generator sets.  Report noncompliant TRUs to CARB's Complaint Hotline.

• Compliance Schedule
  • In-Use Model Year 2022 and Older TRUs
  • New Model Year 2023 and Newer TRUs
  • Zero-Emission Truck TRU Fleet Compliance Schedule
• Compliance Assistance
• TRU Compliance Extensions
• Resources for Carriers, Brokers, Forwarders, Shippers, and Receivers
• Publicly Available Resources for TRU Compliance Checks

Compliance Schedule

In-Use Model Year 2022 and Older TRUs

New Model Year 2023 and Newer TRUs

Zero-Emission Truck TRU Fleet Compliance Schedule

The phase-in schedule for different size truck TRU fleets is shown in the table below. Note that owners should use basic rounding methodology when calculating the required number of zero-emission truck TRUs. If the calculated number of required zero-emission truck TRUs is not equal to a whole number, round up to a whole number when the fractional part is equal to or greater than 0.5, and round down if less than 0.5.

Compliance Assistance

• Frequently Asked Questions for Compliance with the TRU ATCM (Español) - Frequently Asked Questions (FAQ) document on the TRU ATCM and the 2022 Amendments in a question and answer format.

• The documents below help TRU owners find TRU unit and engine labels and the information on those labels that is needed to apply for a CARB identification number:
  • Carrier Transicold Unit and Engine Labels:  This provides helpful pictures showing where to look for the Carrier unit labels and Kubota engine labels.  It also shows pictures of where to look on the unit label for the unit model, model year, and serial number.  There are also pictures showing where to look on the engine label to find the engine manufacturer, model, model year, and serial number.  For further assistance, contact a local Carrier Transicold dealer
  • Thermo King Unit and Engine Labels:  This provides helpful pictures showing where to look for the Thermo King unit labels and Isuzu or Yanmar engine labels.  It also shows pictures of where to look on the unit label for the unit model, model year, and serial number.  There are also pictures showing where to look on the engine label to find the engine manufacturer, model, model year, and serial number.  Thermo King Service Bulletin TT505 provides a look-up table that uses the engine serial number to determine the engine model year of Isuzu engines.  For further assistance, contact a local Thermo King dealer.
• Regulatory Guidance for Electric Standby and Hybrid Electric Systems for Alternative Technology Compliance (Español) - Guidance on how electric standby and hybrid electric systems must be used to qualify as an Alternative Technology and the recordkeeping and reporting that is required with this compliance option.  Note that use of an Alternative Technology may only be used to comply with the in‑use performance standards that apply to model year 2022 and older non-truck TRU engines.
  • ETS Supplier List - Note that this list is not intended to imply CARB endorsement of any kind.  Users of this list are advised to use due diligence in evaluating offerings from the companies on this list.

• TRU Verified Diesel Emission Control Strategy (VDECS) Information. Note that installation of a Level 3 VDECS may only be used to comply with the in-use performance standards that apply to model year 2022 and older non-truck TRU engines.
  • CARB Retrofit Device Verification Database – available to help end users find a compatible retrofit device that is potentially verified for their TRU engine.
  • VDECS Installation/Maintenance Information
  • Managing Hazardous Waste from VDECS
  • Complaints:  Owners that have problems with their VDECS should first contact the installer.  The installer should be able to assist with diagnosis and repairs as well as warranty work, if available.  If the installer is unable to resolve the problem, contact the manufacturer of the VDECS.  Also, contact CARB at (888) 878-2826 or send an email to arber@arb.ca.gov.

• Zero-Emission Truck TRU Technologies – List of currently-available zero-emission truck TRU technologies. Note that this list is not intended to imply CARB endorsement of any kind.  Users of this list are advised to use due diligence in evaluating offerings from the companies on this list.

TRU Compliance Extensions

Compliance extensions are available for specific circumstances as provided for in the TRU ATCM. To qualify, an applicant must demonstrate, with documentation, that they made a good-faith effort to comply by the compliance date by ordering compliance equipment early enough to consider delivery, installation, holiday, and year-end lead times.  

Application Deadlines:

• Compliance Extension Based on Unavailability of Compliance Technology 

  • Prior to December 31st of the applicable compliance year. 

• Compliance Extension Based on Delays Due to Private Financing, Equipment Manufacture Delays, or Installer Delays 

  • Prior to December 31st of the applicable compliance year. 

    • Purchase order deadlines apply: 

      • Replacement units and vehicles: Prior to August 31st of the applicable compliance year.  

      • VDECS Retrofits (diesel particulate filters): Prior to October 31st of the applicable compliance year. 

• Compliance Extension Based on Delays Due to Installation of Zero-Emission Fueling Infrastructure  

  • Utility Infrastructure Upgrade Delay: At least 12 months prior to the zero-emission truck TRU compliance deadline. 

  • All other Delay Types: At least 3 months prior to the zero-emission truck TRU compliance deadline. 

Note:  Notification of an approved compliance extension application based on delays due to installation of zero-emission fueling infrastructure must be made available to the public. See table below for companies with approved extensions and CARB approval notification.

Resources for Carriers, Brokers, Forwarders, Shipper, and Receivers

• Guidance for Brokers, Forwarders, Shippers, Receivers, Carriers, and Drivers on Hiring and Contracting TRU-Carrier Transport of Perishable Goods on California Highways and Railways (Español) – Guidance on requirements for freight brokers, forwarders, shippers, receivers, carriers, vehicle owners, and drivers.

Publicly Available Resources for TRU Compliance Checks

• Transport Refrigeration Unit Compliance Search Page – look-up the compliance status for a specific TRU.
• 100 Percent Compliant Carrier List Search Page – View/search for companies that are 100 percent compliant with the TRU ATCM based on current information in the ARBER database.