ISC is the stepper motor which is to control and compensate air input to smoothness on idling speed, increase idling when air con is switch on..etc.
location below throttle body. with brown colour motor, test with ohm meter, u can get 30 ohm for each terminal. if come with black colour head ( like GTI/ Putral using ) u can get 40ohm at each terminal.
TPS is throttle position sensor, locate at infront of throttle body. check with voltmeter on pin 1 and 2, with normal idling speed, u can get it around 550mV to 950mV.
If not sure, better send to workshop for checking.
Good luck :D