Thread: Td5 ecu:How many reflashes?

td5 ecu is unlimited afaik

i must have tested at least 100 remaps on my ecu in the last 2months and no problems

td5 is unlimited writes....

There is a limited number of timesthat you can write to an electrically eraesable PROM but he number is in the 100,000s or millions or more so I would not worry.

Hiya Fatman
The entire flash memory of the TD5 ECU can indeed be erased and programmed many thousands of times. However Third party equipment such as Nanocom, Rovacom and Faultmate etc, typically only ever erase and reprogram just the areas of the Flash that contain the ECU's Operating system and the Map (Fuelling) data.

There is however another part of the flash memory that is typically never erased and re written and is used for other things.

Most notably, an area is set aside for storing additive programming records.

Third party equipment does not typically write in a new Programming record whenever the OS / MAP Flash contents are reprogrammed, but the Land Rover TestBook system does. The Record stores the VIN, Assembly number corresponding to what the TestBook has just written to the Flash, date of writing and other data.

The Last record is always the active set and is what the Testbook uses to decide what is actually programmed in and if it needs to program in a new data set etc.

That's why a Dealer / Testbook cannot detect a remap. It does not actually know what is in there, only what the last record says was programmed in.

There is only enough room to store so many records, after which the TestBook will probably declare that the ECU can no longer be updated and must be replaced.

Hence LR dealers believe the flash programmability to be limited and perhaps ultimately the reason behind your question.

On some LR ECU's like the M5.2.1 the storable record count is as low as 9, but on the TD5 its something like 17 or 33, i forget which.

I hope this helps.