Hi All,
Having an issue with a buddies 2006 supercharged vette that he bought. Long story short - the original owner told him the fan module was fried and had an aftermarket one wired up. We don't like the aftermarket one because it is sloppy and don't feel it cools as good. He would like to stay with the factory setup and so we are investigating the issue.
So here is what happens when he put in a used module:
Ignition on, key off I try and command the fan on with hp tuners = nothing
Ignition on, key on, fan comes on instantly on cold start up at full blast (AC not on).
Turn the ignition off and the fans remain on for a 300second run cycle.
IF I try and command the fans off any any time with the engine running or during the cool down cycle with hp tuners I get no response.
So in other words, the car is ignoring my pcm commands from hp tuners in the specialty tab using just the VCM
For shits and giggles we installed the previous controller module that the vette came with and the results are exactly the same.
Now, he has eliminated the plug and hard wired the wires from the pcm / power / ground as the hardness before the fan module (up by the subframe) is known to go bad, so that is also ruled out.
Looking at the tune which I am posting here I can tell the following:
The fans are set to come on at startup only after the car hits 168.8*F and only at 11%. Yet, at startup and well below this temperature they are on a full blast?
output control vs state is all set to "1" - I don't know what this function is or what those numbers mean. I thought I saw this tune as being stock as far as the fan settings go, but maybe I am missing something somewhere else? I am not over familiar with the vette tunes so it is possible I am over looking something when trying to diagnose this.
Other thoughts:
We thought maybe it was a PCM issue - but clearly the PCM is needed to command the fans on? But also how is it ignoring direct commands from Hp Tuners to turn on and off?
We thought maybe it is the coolant sensor, but it is reading the coolant temp fine
We thought maybe he got a faulty controller, but what are the odds both are bad and display the same symptoms? Usually when these are bad the fan just doesnt work?
We are both stumped at what to look at to diagnose. Obviously the fan works when plugged in, but not properly and not as commanded. All the issues we have read deal with the control module not working and causing the fans not to work.
Tune attached - thanks to anyone who can help out!new vette tune - Copy.hpt