I may be over simplifying it but, if the TEMP value is within the adjustment range of 105 and 170, it seems that the IF/THEN condition would fine tune your PWM signal already.
I also notice the DUTYCYCLE math needed the parentheses moved.

Code:
IF TEMP > 105 AND TEMP < 170 THEN
    DUTYCYCLE = (170-TEMP)/3 + 222
ELSE 
    DUTYCYCLE = 0
ENDIF