Can I claim full capital cost allowance for my vehicle where I was entitled to claim employee car expenses for jan, feb & mar 2018 only ?

No, you can’t claim the full amount. It should be prorated based on the kilometres you drove for employment purposes. However, we currently have an issue with the T777 form in TurboTax CD/Download that is incorrectly calculating CCA for automobiles, so it may give you the full amount. We are working on a fix for this issue and hope to resolve it soon.