frequent failuer of cooling system and AC after flashing

[odd boy]

Hi,

In many occasion when I tune E38 ecus, the engine coolant gauge fails and the AC goes off. In some events, code P0128 gets on. If I remove the battery or clear the code the car goes back to normal but the issue appears again later after sometime.

If I return the stock file back, the problem goes away for ever. Please advice what could be the reason.

Thanks in advance,

[GMPX]

What year / model vehicle?

[odd boy]

It happened with many cars, the following list is what I recall:

Yukon--------12614088---2008
Tahoe--------12639835---2011
G8 (Holden)---12612381---2007

Mainly happened with the Sierra, Tahoe, Yukon, and G8 Holden version for the middle east. Any model 2007+ but not all of them--

[GMPX]

Ok, all E38 vehicles, anyone else seen this problem?

[odd boy]

By the way in few cases, this issue goes off when I set P0128 to no mil and not reported in case a thermostat is installed and the fan batch is applied. However, MOST of the time it doesn't clear out and stays there until I return back the stock file especially with the stock car "without thermostat installed".

for Example,

Yukon--------12614088---2008 is a stock car with out thermostat installed. He came to me yesterday with the issue and it cleared out only with the stock file.

G8 (Holden)---12612381---2007 , I encountered two cars with the same issue, both had thermostat installed. One of them got resolved with switching off P0128 and the other one needed to go back to stock.

Another example, Tahoe 2007 but I don't have the file in hand now. with out thermostat installed and needed to go back stock.

Please lemme know if the above explanation is unclear.


Thanks,

[etmotorsports]

I have noticed on a 2010 camaro after a flash the ac isn't working but to be honest the cars a/c didn't work very well even before i retuned it. I need to check that out after the idle issue is fixed ill let you know if i see any a/c issues.

[odd boy]

I had the same issue again with two cars today, any help please...

[GMPX]

Odd Boy, the ones you have trouble with, are these only with the thermostat removed and the Fan rescale patch applied?

[odd boy]

yes sir, except one Yukon--------12614088---2008

I don't want to push you but I am losing these customer, they think I made problems to their cars!!!!

[GMPX]

Odd Boy, I think you need to do a process of elimination. If you can put the stock file back in and everything starts working again then it's got to be something being modified in the tune that is causing it.
Like the Yukon, have a look at the history of changes and think about something that has been disabled that may have upset the A/C system. I must admit I can't think of what could be causing it. I know David posted in this thread about a 2010 Camaro that has been a problem car for him that is having A/C issues, but apart from you two I have not heard of these sort of problems with E38's, unless files from different vehicles are flashed in.