Little computer work on Sat. night...

Icc Fault Trips When Cooling Fan Comes On. That We Know.
So, Here's What We Do:

Works every time.

Runs fine till the fan comes on. Then it starts a real light 'miss'. Really even hard to tell, even at idle. Only way I knew for sure was at speed, I could tell by fuel economy that it had reverted to open loop.
Zeits' said his ran pretty bad after it tripped the ICC fault. Strange, cause I know it's the same problem bad PCM.
Sometimes the ICC fault was already in the computer after clearin' codes. And so are a few other codes sometimes, like VSS signal loss, which doesn't trip until after the car has MOVED!!!
I shoulda' figured it out long ago, but I just wanted to know for sure it was the PCM. It says right there in the FSM, that ICC fault diagnostics ENDS at a bad PCM. I was hardheaded, and tried to find other stuff to tie into the problem. I sorta' did, but 'sorta' don't catch no fish.
You did way more work than almost any of us would have done. I really thought you had something there for a while with the fan causing it.
Hope you find one at a decent price. I didn't even find one with a quick search on the bay of E.

I didn't see any scorch marks, no fat capacitors, no toasty smell, like I've seen on pc motherboards. Doesn't matter tho', it's done.
I already zipped it back up, and put it back in the car. It showed C12 good communication, 1 module clear, 4 module clear, 9 module gave H72 VSS loss no good until the car has MOVED!!! It was tryin' to trip the door locks too, which I had seen before on a few occasions.
Then I started it up, and it idles as good as ever. Soon as it warms up tho', I know what's gonna' happen...
I'm inclined to just buy a reman PCM from RockAuto...it's only $95 plus core and shipping.
Hope everything goes well for you!
Clay

Part # at Advance and Auto Zone is the same - you might need this - 771333F SAME FOR '95 - I saw it on the computer screen. They DO need your VIN when it's ordered - make sure the VIN gets to the vendor's ears in front of ya'!!! Otherwise you're gonna' have to go to the dealer$$$.
They want the old box. Drat! I wanna' see how it works.
The Best of Corvette for Corvette Enthusiasts

I'm sure the whole Advance Auto network is on the same database - here's a copy of the receipt. The handwritten # on the pepsi receipt is the ORDER # for the PCM - maybe some help there...
The part is THE SAME for the '95 - I asked, and saw it on the screen - but you WILL have to get the sales guy to give the Cardon guy your VIN!!!
Last edited by schrade; Aug 4, 2008 at 12:19 AM.

Thanks for the info! Again...if it works for you, I'll pull the trigger also. The only three things it could POSSIBLY be are a bad Opti, bad harness, or bad PCM.
Since my DelTeq system tells me when the Opti is putting off a bad signal (LED on the "brain box" blinks if the signal is weak) and it has not done that at all over the past few weeks, I'm ruling out a bad Opti or bad wiring harness...for now. $100 is cheapness if it fixes this stupid problem. My fuel economy has gone to crap so I'll make up the rebuilt PCM cost in reduced gas consumption and repairs down the road...

That was the email that the guys at the local store got this morning. Another 20 minutes on the phone, and NO success. A lead - Blue Streak, but no contact yet.

EDIT:
Just got off the phone with Blue Streak. Everything arranged... I thought.
me: "Where do I ship it to?" (for reman)
them: "Who are you with?"
me: "I got your name from a retailer."
them: "We don't deal directly with the public."
me: (getting short now) "Okay, gimme' some names - some retailers' names!"
them: "Pep Boys, Carquest..."
me: "Thanks click"
Headed for Car Quest in the am. $120.00 + S&H; 10 - 14 days.
ALL THE *******!!!!!!!!!!!!!!!!!!!!!!!!!!!
AGHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH H
HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH
ARGHHHH.
#(^&)&%)&w%(*&#@%$&^(%%#@*&^*&*(&@#*&^*& %^%^&*)^%#$
Last edited by schrade; Jul 22, 2008 at 04:09 PM.
Wow...looking forward to how this works out for you. Is CarQuest giving the 'puter to you already programmed and ready to go? Better be. Does the $120 include core, or are you bringing your "split" PCM to them as a core exchange?
Actually, I hope that I don't get YOURS as a reman unit!!!

Wow...looking forward to how this works out for you. Is CarQuest giving the 'puter to you already programmed and ready to go? Better be. Does the $120 include core, or are you bringing your "split" PCM to them as a core exchange?
Actually, I hope that I don't get YOURS as a reman unit!!!

I didn't do anything to mine, just broke the seal. The multimeter and the hammer was for laffs. I already put it back in and fired it up. Ran just as good as ever.
Till the glitch lights up, and trips up stray codes and misfire...




