DEALERS BITE!!! Propriotory issues as you speak of.
01' van. needed an ignition modual. I knew this. Plain old common sence and logic.
3 days of return visits and $80 min. diagnostic charges x 3. Plus the $180 charge for keys.
4TH visit. I TOLD them replace the ignition modual (as I requested at the first PHONE CALL).
$173 peice. done... have had no problem since!!!!
I told them the problem. They soaked me!!!! Most are 1 dementianal andf bad to boot!!!! total: $453.73. To change it as requested... $243.

Any good mechanic worth his/their salt- has access to all but a few computer related equipment and programs.If registerd, No problems with the factory. On any issue.

Dealers are THIEVES!!!!! But a needed evil! Created by them.

Dealers. Last resort ONLY!!