XFI IAC Status "12" --- Thermal Shutdown

[Blazer406]

Any ideas what could cause this? Tried two IAC's both do the exact same thing... and appear to be working when you take one out... ground body... and hook back to harness and start the car.... (plunger moves).

Car throws a error code 128 while cranking or running.

IAC status is 15 with engine off... key on.....

Begin turning car over to crank.... 1 sec later (before engine even starts)... it has changed status to "12" which according to the help section in the manual.... is "thermal shutdown". As soon as the IAC status changes from 15 to 12.... it throws the error code 128 and the SES light stays on....

 

[d90dan]

I've seen two cars, after upgrading to a XFI, with this problem.
Each time the car had a bad IAC that took out the control circuit on the XFI. That's why the other IAC gives the same failure. The fix was to get the box repaired by FAST.
The weird thing is the bad IAC never seemed to affect the cars before the XFI install. Possibly they had been adjsuted such that they were previously running off the throttle blade only?

There is an old post that gives the resistance range to determine if the IAC is good or bad, but I can't seem to find it now.

 

[Otto J]

Understand this also about the XFI
IF YOU PLUG AND UNPLUG THE IAC WITH THE KEY ON IT WILL BURN THE IAC DRIVER!!!!!!

 

[Blazer406]

Understand this also about the XFI
IF YOU PLUG AND UNPLUG THE IAC WITH THE KEY ON IT WILL BURN THE IAC DRIVER!!!!!!

We never did that I don't think. This issue showed up at BG.... and to my knowledge... the IAC never got unplugged while we were there.

I take it this has happened to you?

I guess if this is it.... it would explain the inconsistant idle we are seeing....

 

[RICHIE HIGH PSI]

Understand this also about the XFI
IF YOU PLUG AND UNPLUG THE IAC WITH THE KEY ON IT WILL BURN THE IAC DRIVER!!!!!!

So if you have a poor connection at the iac it can ruin a box???
:frown:

 

[S2V6RACER]

So if you have a poor connection at the iac it can ruin a box???
:frown:

Wow, what a joke. You would think they would have thought about some kind of protection.

 

[Blazer406]

I guess I should update...

Sent the box back to FAST.... they fixed and sent back....

Installed it and got the car back running again....has been fine... IAC seems to work fine.

We now have a hole new issue.... not getting a crank signal while attempting to start.... so no injector pulse... Installing new crank sensor today...We just put a new one on at BG this year.... car hasn't been 100 miles since BG..... This sux.

 

[Blazer406]

Update...

Found that problem..... ignition module went out..... was a generic one you can get from advance auto parts. Put a spare one on the car.... runs great again....