eMMC woes for Tesla were entirely avoidable

Bringing a product to market is challenging. With something as sophisticated as a car there are years of planning and a great deal of investment involved. New models have to stand on their own feet as well as contribute more widely to the brand. All of which makes Tesla’s recent recall of over 130,000 Model S and Model X cars surprising – even shocking.

Tesla's eMMC woes were avoidable - flash memory solutions

eMMC causes recall

The recall was due to an issue with the eMMC memory in the Media Control Unit – the driver’s screen-based information centre. In its official statement, Tesla blames “accumulated wear” which might result in “a persistent blank center display that does not recover after restarting the touchscreen, loss of certain functionalities, and/or a vehicle alert,” saying this was a signal that there is “memory storage device degradation.” The recall has been made to both update software and to “proactively upgrade, free of charge, the available memory storage on your vehicle from 8GB to 64GB.”

The recall was initiated by the US National Highway Traffic Safety Administration which, in a letter to Tesla, made it clear that in affected vehicles part of the 8GB eMMC memory’s storage capacity was used every time a car was started, that the eMMC’s NAND cell hardware fails when storage capacity is reached, and that at this point the Media Control Unit fails, creating safety issues warranting the recall.

What went wrong at Tesla?

It seems that whoever specified this eMMC did not realise some fundamentally important things about flash memory. Maybe they weren’t aware that there was a write to the memory every time the car was started. Maybe they did know that, but didn’t appreciate how much data was written, or how many vehicle ‘starts’ the eMMC could cope with before it failed. Maybe they specified an 8GB eMMC card because it is entry level, and therefore lower cost than a card with more memory, and they were trying to keep build costs down.

Maybe – and at Cardwave we’ve seen this happen before during the design process  –  the card was specified at a point when a particular load was anticipated, and its 8GB was deemed to be perfectly adequate, and then as development of the car progressed, engineers and programme managers started adding more features, and asked the card to do more work than it was originally specified for.

This is all speculation, and there’s a lot that we don’t know in relation to this particular incident. But we do know that this kind of issue really shouldn’t occur, particularly in a high end product.

How it could have been avoided

As a trusted provider of memory solutions, we’d expect to take every step to ensure it doesn’t happen. Indeed we have done precisely that. We worked with a leading automotive manufacturer to help them specify the right quality of SD card for their navigation and entertainment system. Initially the automotive company had planned to purchase consumer grade cards, but we explained why consumer grade cards weren’t appropriate, helping to source cards of the appropriately robust quality and also troubleshooting an aspect of the wider system which was causing SD card failure.

A key outcome of our work with this automotive manufacturer was to help them specify the right SD cards and to steer them away from a choice which would potentially have given them major headaches and caused significant expense and reputational damage down the line.

At Cardwave we believe this is part of our job. We know that not everyone understands the complexities of flash memory like we do, and actually, in the case of our automotive manufacturer customer, we would not expect the engineers involved to have the same level of nuanced understanding as us. This is our specialism, and it’s a complex, multi-faceted field where seemingly small factors can have a huge impact.

What next for Tesla?

To get back to Tesla, the company now has some significant reputational damage to repair. As a car brand Tesla is an outlier. It is associated with innovation, with the future, and with understanding how to push technology hard to get the desired results. The Media Control Unit is in many ways the heart of the car – the information hub. And it failed due to an issue with a memory card. Reputational damage has been done, and Tesla now has to work to fix that as well as deal with the expense of a product recall and refit.

Perhaps Tesla should have come to Cardwave for sourcing and advice. Well, our door is always open.