why is my Tesla Model S Plaid/Refresh (2021-present) battery overcharging when using AC?

Tesla Model S Plaid/Refresh (2021-present)

Error Codes

2-4 hours

Time

medium

Difficulty

high

Severity

3 min read

503 words

⚠️ Safety Warning

This issue requires immediate attention. If you are not experienced with automotive repairs, consult a professional mechanic. Working on critical systems can be dangerous.

Problem Statement

Learn how to diagnose and fix the AC overcharging issue in Tesla Model S Plaid. Step-by-step guide with diagnostic procedures and repair instructions.

Affected Component

HVAC

Estimated Time

2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the battery before working on electrical systems.
•Allow the vehicle to cool before inspecting the AC system to avoid burns.

Symptoms

•Battery charge level exceeding 100%
•AC system functioning intermittently or poorly
•Increased battery temperature
•Reduced driving range
•Warning messages on the dashboard related to battery or charging

Diagnostic Steps

1
Check for any error codes using the Tesla service diagnostic tool.
2
Inspect the AC system for any refrigerant leaks or malfunctions.
3
Verify the battery management system (BMS) settings and software version.
4
Monitor battery temperatures and charging rates during AC operation.
5
Review Tesla's service bulletins for any known issues or recalls related to the battery or AC system.
6
Inspect the charging equipment and connections for any faults.

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

✓Test the affected component to ensure it functions correctly
✓Check for any error codes or warning lights
✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

•Follow the manufacturer's recommended maintenance schedule
•Address warning signs early before they develop into major issues
•Use quality parts and fluids recommended for your vehicle
•Keep detailed records of all repairs and maintenance

Tools & Equipment Required

•Tesla service diagnostic tool
•Refrigerant gauge
•Basic hand tools (screwdrivers, wrenches)

Parts Required

•Refrigerant (if AC system is low)
•Replacement seals or hoses (if leaks are found)

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Diagnostic Steps

1
Check for any error codes using the Tesla service diagnostic tool.
2
Inspect the AC system for any refrigerant leaks or malfunctions.
3
Verify the battery management system (BMS) settings and software version.
4
Monitor battery temperatures and charging rates during AC operation.
5
Review Tesla's service bulletins for any known issues or recalls related to the battery or AC system.
6
Inspect the charging equipment and connections for any faults.

Solution

1. Preparation

Ensure the vehicle is parked on a level surface.
Disconnect the vehicle from any charging station.
Gather all necessary tools and parts.

2. Update Software

Sub-steps:
- Connect the Tesla to Wi-Fi.
- Check for any available software updates in the vehicle settings.
- Follow on-screen prompts to install updates, if available.

3. Inspect and Service the AC System

Sub-steps:
- Open the front trunk to access the AC components.
- Use a refrigerant gauge to check the AC system pressure.
- If undercharged, recharge the AC system with the appropriate refrigerant type (R134a or R1234yf).
- Inspect the AC compressor for proper operation.
- Check for any visible leaks in the AC lines and seals.

4. Check Battery Management System (BMS)

Sub-steps:
- Use the Tesla diagnostic tool to access BMS settings.
- Reset the BMS if necessary, following Tesla’s specific reset procedures.
- Monitor the battery's charging behavior after the reset.

5. Inspect Charging Equipment

Sub-steps:
- Examine the charging cable and connectors for wear or damage.
- Test the charging station with another vehicle to ensure it is functioning properly.
- Replace any damaged components as necessary.

Tools Required:

Tesla service diagnostic tool
Refrigerant gauge
Basic hand tools (screwdrivers, wrenches)

Parts Required:

Refrigerant (if AC system is low)
Replacement seals or hoses (if leaks are found)

Estimated Repair Time: 2-4 hours

Safety Warnings:

Disconnect the battery before working on electrical systems.
Allow the vehicle to cool before inspecting the AC system to avoid burns.