Reset IAC via PCM
Thread Starter
Drifting
Joined: Aug 2009
Posts: 1,972
Likes: 243
Reset IAC via PCM
I installed a 52mm throttle-body last night (a bored stocker). I haven’t fired it up yet and before doing so I’d like to reset the IAC.
I’ve used Freescan in the past on another OBD I GM car to successfully reset the IAC via the PCM.
My Corvette is a 94, which is still OBD I but it has the OBD II style connector. I have an AKM cable that connects to the ALDL and to the laptop via USB. I’ve had no luck in getting Freescan to connect using this cable (Freescan DOES support the 94 Y body). I believe the problem is that Freescan is looking for a serial port and the cable is USB. I used the cable once a long time ago, to reflash the PCM for when I changed the gears to 4.11s. I used a trial period of Tunercat (I had to buy the definition file).
So, how else can I reset the IAC via the PCM?
Any other Freebie software out there that connects? I have TunerProRT but I have it setup for another car and don't want to tweak the settings definitions (I struggle to get it back to where I had it). Besides, I'm not sure that TPRT can reset the IAC and I don't have the definition file for the Y body anyway.
I’ve used Freescan in the past on another OBD I GM car to successfully reset the IAC via the PCM.
My Corvette is a 94, which is still OBD I but it has the OBD II style connector. I have an AKM cable that connects to the ALDL and to the laptop via USB. I’ve had no luck in getting Freescan to connect using this cable (Freescan DOES support the 94 Y body). I believe the problem is that Freescan is looking for a serial port and the cable is USB. I used the cable once a long time ago, to reflash the PCM for when I changed the gears to 4.11s. I used a trial period of Tunercat (I had to buy the definition file).
So, how else can I reset the IAC via the PCM?
Any other Freebie software out there that connects? I have TunerProRT but I have it setup for another car and don't want to tweak the settings definitions (I struggle to get it back to where I had it). Besides, I'm not sure that TPRT can reset the IAC and I don't have the definition file for the Y body anyway.
Drifting
Joined: Aug 2004
Posts: 1,430
Likes: 2
From the 92 FSM. Not sure about the 94
Reset IAC valve pintle position:
A. Depress accelerator pedal slightly.
B. Start engine and release accelerator pedal, run engine for 5 seconds.
C. Turn ignition “OFF” for 10 seconds.
D. Restart engine and check for proper idle operation.
Reset IAC valve pintle position:
A. Depress accelerator pedal slightly.
B. Start engine and release accelerator pedal, run engine for 5 seconds.
C. Turn ignition “OFF” for 10 seconds.
D. Restart engine and check for proper idle operation.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
The PCM resets the IAC every time you shut off the ignition. That's why you have to wait 10 seconds to restart the engine. If your car does a MAF burnoff, it is also done during this time.
