2013-2018 Toyota Avalon Rear Climate Control & USB Port: A Buyer's and DIY Guide

Variant and Compatibility Warnings

• 2013 Models: This part fits the Limited and Hybrid Limited trims only.
• 2014-2018 Models: This part fits all trims that have rear climate controls, which typically includes the Limited and Hybrid Limited.

Always verify that your vehicle has the rear climate control feature before purchasing. The part number for this specific rear unit is 55900-07210. Do not confuse this with the main front dashboard climate control unit, which is a much more complex and expensive part.

Common Symptoms of Failure

Problems with this unit can manifest in two ways: issues with the climate control functions or issues with the USB/AUX ports. A forum user with a 2013 Avalon reported simultaneous failures of the USB system and the automatic climate blower, suggesting an internal electronic fault within the control module.

USB & AUX Port Symptoms

• Device Not Recognized: You plug in a phone or USB drive, and the infotainment system does not detect it.
• No Charging: A connected device does not charge, or charges extremely slowly.
• Intermittent Connection: The connection repeatedly drops and reconnects, interrupting music playback or charging.
• AUX Port Issues: Static, popping, or no audio when using the 3.5mm auxiliary jack.

Climate Control Symptoms

• Unresponsive Controls: Turning the knob or pressing buttons has no effect on the rear temperature or fan speed.
• Fan Stuck on One Speed: The rear fan may not adjust automatically or manually.
• No Backlight: The illumination for the knob and display fails, making it impossible to see at night.
• Display Malfunctions: The temperature display is blank, shows garbled information, or is inaccurate.

Diagnosing the Problem

Before replacing the whole unit, follow these diagnostic steps to isolate the issue.

1. Basic USB/AUX Troubleshooting: The issue is often the cable or device, not the car's port. Try a different, high-quality USB cable and a different device to see if the problem persists.
2. Inspect and Clean the Ports: Use a flashlight to look inside the USB and AUX ports for lint, dust, or other debris. A can of compressed air or a non-metallic tool like a wooden toothpick can be used to gently clean out any obstructions.
3. Check the Fuses: A blown fuse can disable the power to the entire unit. Consult your owner's manual to find the fuse panel and identify the fuse related to the accessory power outlets or climate control system. If other power outlets in the car are also dead, a blown fuse is the most likely culprit.
4. Reboot the Infotainment System: For connectivity issues, a soft reset of the main infotainment system can sometimes resolve communication glitches. On many Toyotas, you can do this by pressing and holding the volume/power knob for about 10 seconds until the system reboots.

If these steps do not resolve the issue, and especially if both the climate and USB functions are failing, the control unit itself has likely failed internally.

Buying a Used Rear Control Unit

Since new aftermarket versions of this specific module are not produced, your options are a new OEM part or a recycled OEM part. Given the significant cost savings and high availability of used units, they are an excellent choice for this repair.

What to Check Before You Buy

• Verify the Part Number: Ensure the part you are buying is stamped with 55900-07210. While other units may look similar, internal electronics can differ.
• Inspect for Cosmetic Damage: Check for deep scratches on the faceplate, display screen, and control knob. While minor wear is expected, significant damage could indicate abuse.
• Test the Knob: The control knob should turn smoothly with distinct clicks. It should not feel loose, wobbly, or gritty. If only the knob is broken on your existing unit, you can purchase it separately (part number 87123-07010) for just a few dollars.
• Examine the Connector: Look at the electrical connector on the back of the unit. The pins should be straight, clean, and free of any corrosion or damage.
• Check the USB/AUX Ports: Look inside the ports for any signs of physical damage, like bent pins or broken plastic.

Cost of Replacement

The cost to replace the rear climate and USB unit is relatively low, especially when using a recycled OEM part.

Replacement Procedure Overview

Replacing this unit is a straightforward DIY task that requires basic tools.

• Difficulty: 2/5 (Easy to Moderate)
• Estimated Time: 30 minutes
• Tools Needed: Plastic pry tools, Phillips head screwdriver or 10mm socket (depending on fastener type).

While a specific video for the Avalon's rear console is not readily available, the process is similar to other Toyota interior component replacements.

1. Move the front seats forward to get better access to the rear of the center console.
2. Using a plastic pry tool, carefully pry around the edges of the trim panel that surrounds the control unit. It is held in by clips.
3. Once the trim is loose, you will see the mounting screws or bolts holding the control unit in place. Remove them.
4. Gently pull the unit out and locate the electrical connector on the back. Press the release tab on the connector and pull it straight out to disconnect it.
5. Connect the new unit, reinstall the mounting screws, and carefully press the trim panel back into place until the clips snap in securely.
6. Turn the vehicle on to test both the climate control functions and the USB/AUX ports.

Related Recalls and Service Bulletins

While there are no specific recalls or TSBs for the rear climate/USB unit itself, owners of 2013-2018 Avalons should be aware of a few major safety campaigns for this generation.

• Airbag Control Unit Recall (NHTSA 20V024000): Affects 2012-2018 Avalons. The airbag ECU can malfunction in a crash, potentially preventing airbags and seatbelt pretensioners from deploying. Dealers will install a noise filter on the wiring harness to correct this.
• Fuel Pump Recall (NHTSA 20V012000): Affects some 2018-2019 Avalons. A failing fuel pump could cause the engine to stall.

You can check if your specific vehicle is affected by these recalls by entering your VIN on the NHTSA website.