no voltage at iac
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RE: no voltage at iac
I would just check all of your fuses, without studying a wiring diagram I don't know for sure which one controls that function. If nothing else you might find a fuse that you didn't know was blown. It's just not a bad idea to be sure before you drop the big money on a computer then you have to take it to the dealership to have it flashed.
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#8
RE: no voltage at iac
According to the FSM (2001 yes?), there's 4 wires used in that circuit. 2+ and 2- ... it's a "stepper motor" ... it doesn't run ... it positions. The 4 colors are Gray/Red, Yellow/Black, Brown/White and Purple/Black. The PCM pulses the "motor" to various positions based on, among other things, engine coolant temperature and intake air temperature. You may not have a PCM or IAC problem. Garbage In - Garbage Out ... If one of the sensors is bad ...
Oh ... you don't show any voltage across those two wires for one of two reasons ... they either both have +12 on them (voltage is a DIFFERENCE in potential) or one has +12 and the other is open (because the PCM wants it that way). You have to read voltage from each wire to ground and the fact that a wire doesn't have a voltage on it at any given time in a digital circuit is meaningless.
What made you check voltage? What are your symptoms? Truck won't run?
Oh ... you don't show any voltage across those two wires for one of two reasons ... they either both have +12 on them (voltage is a DIFFERENCE in potential) or one has +12 and the other is open (because the PCM wants it that way). You have to read voltage from each wire to ground and the fact that a wire doesn't have a voltage on it at any given time in a digital circuit is meaningless.
What made you check voltage? What are your symptoms? Truck won't run?
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RE: no voltage at iac
I tested for voltage because the truck has a rough idle. The pintle on the IAC would not move so I bought a new one and that didnt help the idle problem. The Haynes manual said to check for voltage between the purple/black wire + and the brown/white wire - . Since there is no voltage I figured the pcm was bad. The computer has not thrown any codes but the IAC is not working , will not adjust idle when AC is on etc.