What causes touchscreen (MCU) failure in the 2015 Tesla Model S, and how can it be fixed?

 
Causes of Touchscreen (MCU) Failure in the 2015 Tesla Model S
 

The touchscreen or Media Control Unit (MCU) in the 2015 Tesla Model S is primarily responsible for controlling various features of the vehicle, including navigation, climate control, and entertainment systems. Several factors can lead to the failure of the touchscreen or MCU:

• eMMC Memory Wear: One of the most common causes of MCU failure is the excessive wear of the embedded MultiMediaCard (eMMC) flash memory. Over time, the memory can degrade due to frequent writing and erasing of data, which results in slower performance and eventual failure of the MCU.
• Overheating: Continuous use of the touchscreen can generate substantial heat. Over time, the excessive heat can affect the performance and reliability of the MCU components.
• Software Glitches: Frequent software updates and potential bugs within the system software might lead to erratic behavior or crashes of the MCU.
• Electrical Issues: Power surges or other electrical issues can damage the delicate circuitry within the MCU, causing failure or reduced functionality.

 
Steps to Fix Touchscreen (MCU) Failure
 

Repairing or replacing the MCU in a 2015 Tesla Model S involves several steps. Here’s a detailed guide:

• Restart the MCU: Perform a soft reset of the MCU by holding down the two scroll wheels on the steering wheel until the Tesla logo appears on the screen. This can sometimes resolve minor software glitches.
• Software Update: Ensure the vehicle's software is up-to-date. Tesla regularly releases updates that may contain fixes for known issues with the MCU.
• Contact Tesla Service: If a reset or software update doesn’t solve the problem, contact Tesla Service. They can diagnose the issue remotely and may reflash the MCU firmware or replace faulty components.
• eMMC Replacement: If the eMMC memory is worn out, it may need to be replaced. Tesla Service Centers offer a retrofit program that includes replacing the faulty eMMC with a more durable version.
• Cooling Enhancements: Adding aftermarket cooling solutions or ensuring proper ventilation around the MCU can help in preventing overheating issues which might prolong the life of the MCU.
• Hardware Replacement: In severe cases where the MCU hardware is damaged beyond repair, a replacement unit may be necessary. Authorized Tesla Service Centers can replace the entire MCU module.

 
Preventative Measures
 

While some failures may occur inevitably, you can take steps to prolong the life of the MCU:

• Regularly Reboot the MCU: Periodic reboots can help clear cached data and prevent software issues from accumulating.
• Stay Updated: Keep the vehicle’s software updated to ensure you have the latest fixes and improvements.
• Monitor Performance: Pay attention to the touchscreen's responsiveness and performance. Early signs of lag or unusual behavior should be addressed promptly to avoid complete failure.

By following these steps, you can maintain the functionality of the touchscreen (MCU) in the 2015 Tesla Model S and take appropriate actions if issues arise.