Changing ECU

[DeeTurbo]

The way I understand it is basically the memory for fault codes can only be cleared 50 times on my car and it looks like the last fault that had occurred stays in the ECU.

This was taken from another forum;

These ECU's use EEPROM chips which have a limited number of guaranteed read/write cycles.
For safety and reliability as well as legal reasons they decided to allow 50 write opperations.

Later systems might use more up to date components but still limmit the opperations allowed
and some actually lock-up after the max number allowed.

For pugs, it's easy to check how many are logged-on by going to 'History' in PP2000 and seeing how many entries
are stored.

So if you get the light up don't just clears the codes and leave it, you should find out whats causing it and fix it.