Hi Preethi,
I have not used plantuml on CodeWarrior or KDS, but it should work if the plug in supports the eclipse version used as base for the IDE. How did you installed the plugin? make sure you followed this guide:
Integration with Eclipse
You could also check the plantuml Questions & Answers page and see if someone has encountered the same issues:
PlantUML Q&A
Hope it helps!
Best Regards,
Carlos Mendoza
Technical Support Engineer