2021 Toyota Connectivity Issues TSB

Symptoms of Connectivity Problems

Owners of certain 2021 Toyota vehicles may experience a range of connectivity problems. These issues can affect various in-car services and applications, leading to frustration and reduced functionality. The symptoms often point to underlying communication difficulties within the vehicle's Digital Communications Module (DCM).

Common symptoms include:

• The red SOS LED remaining illuminated after the bulb check.
• The Toyota App being inoperative or failing to accept activation codes.
• The SOS call center not receiving the vehicle's location promptly.
• Receiving "error 42" messages when attempting to use commands through the Toyota App.
• Inability to remote start the vehicle with the key fob (if equipped).
• Difficulties subscribing to remote services or activating Wi-Fi.
• Destination Assist features being inoperative.
• A depleted 12V vehicle battery when the ignition is off.
• The vehicle being unable to reconnect to the network after losing connection.

Fault Code

These connectivity issues are frequently accompanied by a specific Diagnostic Trouble Code (DTC).

Code	Description
B15A804	DCM communication error / internal fault

This DTC, B15A804, indicates a problem within the Digital Communications Module, which is central to the vehicle's telematics and connectivity features. If you are experiencing Toyota Camry connectivity issues, checking for this DTC is a key diagnostic step.

Diagnosis and Trigger Conditions

Diagnosis typically involves verifying the presence of DTC B15A804, either as a current or historical code. The conditions described above, such as the red SOS LED staying on or the Toyota App being inoperative, are direct indicators that the vehicle is experiencing the fault. The issue can manifest in various scenarios, from initial activation problems to ongoing service disruptions or even battery drain when the vehicle is off.

Repair Procedure

Toyota has released a Technical Service Bulletin (TSB) to address these connectivity problems. The recommended repair involves a specific procedure for the Digital Communications Module (DCM). This procedure includes a DCM reset followed by a firmware update.

This update is designed to resolve the internal communication errors that lead to DTC B15A804 and the associated symptoms. Dealers will follow the detailed DCM Reset and Firmware Update Procedure outlined in the bulletin to ensure the module operates correctly.

What Owners Should Do

If you own a 2021 Toyota Camry, Avalon, RAV4, Corolla, or Venza and are experiencing any of the described connectivity issues, including a persistent red SOS LED or problems with the Toyota App, it is recommended to contact your authorized Toyota dealership. Inform them about the symptoms and mention the potential for DTC B15A804 or general Toyota Camry connectivity issues.

The dealership will be able to perform the necessary diagnostic checks and apply the DCM reset and firmware update as per the Technical Service Bulletin. This repair is typically covered under warranty if your vehicle is within the applicable warranty period.

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Source: NHTSA ID 10203549