IAC Check Engine light maybe ECU

[l3igl3ang]

yeah for some reason my Check engine light comes on saying my IAC is bad and the car miss's a little and even dies for no reason and has sluggish power when driveing it only dose it when the light comes on then gose back off iv'e changed the IAC with a working one from my wrecked car but still says its bad could it be the wrieing maybe or the ECU messing up and if its the ECU could i use one from me wrecked car cause there both the same year and model.

 

[TotalEclipse112]

You could but it dosen't sound like the ecu, sounds more like your car is taking in unmeterd air somwhere. That tricks the ecu into thinking the IAC is bad and letting too much air. Is your car OBDII or OBD I it would be easier to diagnose if I could know that.

 

[l3igl3ang]

i think its odb2 but i just been useing the key to get the check engine to flash turning the key off and on 6 times then it flashs the codes to me and its always 25 for the code a bad iac

 

[TotalEclipse112]

So let me ask this since you have to get the car to flash the code its a 95 or older. Those are OBD I. Not very accurate when it comes to this kind of diagnosis. Since you already have another ecu try swapping that out, if the problem still persists start looking for a vacum leak some where after the MAF.

 

[l3igl3ang]

yeah the code in my books says code 25
IAC motor circuits. A shorted condition is detected in one or of the IAC motor circuits.

 

[TotalEclipse112]

Try looking for a short in the IAC wiring from the ecm, it would show up as excessive resistance on a meter. Problem might be a short to ground in there.