A/C not working when check engine light shows,

I have indica V2 DLS 2008, when I start the engine A/C is
working perfectly, but after 5 min travel the A/C stops
working and the check engine light comes, but rpm meter
and speedometer works fine, when ever i restart the engine
the A/C works fine for another 5 min, and whenever the
check engine light turns on there is a tick tick sound from a
sensor near the accelerater cable in the engine hood,   I have
also changed that sensor, but still the problem is not
resolved, and no one able to fine the problem,