Hi Kesavan,
The section [12.2](http://openid.net/specs/openid-connect-core-1_0.html) of the OpenID Connect states this:
> "Upon successful validation of the Refresh Token, the response body is the Token Response of Section 3.1.3.3 except that it might not contain an id_token".
He seems like to get a new ID token you have to go through the authorization code flow again.
There is a way to do that without prompting to user to authenticate again.
For more details check this [link](https://stackoverflow.com/questions/25686484/what-is-intent-of-id-token-expiry-time-in-openid-connect).