another auto repair question

[MrNoBody]

Cary wrote:
Disconnecting the battery does not clear OBDII (since 1996) codes.

It's part of the spec, specifically designed to prevent "shade-tree" mechanics from clearing codes without resolving issues.

The reality today is, though, that since OBDII was introduced, the price of entry for a scanner/code resetter has become minimal, and anyone can buy one for $20, as mentioned. Then they can clear codes at will.

.this
Specifically, OBDII writes the SRS & Emissions codes in F-RAM that might be read
with a "$20 scanner" but not modified and loss of power does not erase it.
That takes specialty equipment and licensed software.
Almost all Euro vehicles also now have the VIN & vehicle security coding in ROM; it can only be read.