iac trouble

[white90gsx]

Hey everyone I'm reposting in the proper spot sorry for the mistake earlier. OK my 95 tsi is having a case of idle surging between 1k and 2500k and on startup it revs to 4k then to its surging up and down my computer is spitting the code p0505 idle air controller system so i went and bought a new iac i put it in and still doesn't fix anything and the computer spits the same code. I read up and searched around and found how to test the ohms i didn't quite understand how to do it even with detailed instructions so lets rule that out for a few until my buddy comes down and helps me next week but i kinda need it fixed before that is there any other things i could look for?


Thanks Chris

 

[brute]

From vfaq:

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There are six pins on the ISC. They are labeled 1 2 3 across the top and 4 5 6 across the bottom. (see above)

* Measure the Resistance between pin's 1-2, 2-3, 4-5, and 5-6
* Each pair of pins measured should read 28-33 Ohms
* Note: The values should measured with the car off and cool!
* If any of the "coils" (which is what you're testing) are bad then your ISC needs to be replaced
* If all the coils were good there's one other thing to check on the ISC

* Use a 6volt battery (lantern or camera battery) and apply 6 volts to the ISC motor.
* Use jumper wires to connect the positive (+) terminal of the battery to terminals 2 and 5 of the ISC and the negative battery terminal to terminals 3 and 6 of the ISC.
* If there is no movement or vibration from the motor, then it is bad
* Note: The use of a 12volt battery will destroy the ISC motor!!

Basically, you just take an Ohm meter set to test resistance (it's the one that has the Greek letter omega), put one prong on one pin and the other prong on the other end. It will measure the resistance.

 

[white90gsx]

Ok when you say isc is that the same as iac?

 

[Locke]

Ok when you say isc is that the same as iac?

Essentially, yes.