Triggering lo and Hi speed fans VT V6

[commodoredave]

no turbo or scharge.
Does anyone know which sensors and in what sequence the fans are triggered to operate.
Coolant temp sensor?
Oil temp sensor?
other?
Do different sensors trigger the different fans?
getting a code 92 (lo speed fan no bcm response) but fan comes on ok during hot days/slow traffic driving.

 

[Immortality]

Thermofans are primarily switched on/off from the coolant temp sensor but the AC system will also trigger the fans depending on the system pressure. Road speed is also a factor, generally above a certain speed the thermofans won't turn on ( about 50km/h IIRC).

The high speed fan is triggered directly from the PCM, the low speed fan is triggered from the BCM via the Canbus system.

Fans turn on/off at the following temps.

 

[Lex]

getting a code 92 (lo speed fan no bcm response) but fan comes on ok during hot days/slow traffic driving.

Have you tried replacing the low speed fan relay with the correct relay?

 

[lout]

this is a results based fault code (i am having a joe biden moment and cant think of the correct term)
basically bcm has requested fan, but engine did not cool down
it does not mean the fan did not operate
so could be any number of causes

 

[BlackVXGTS]

The attached items from the Holden VT/VX Service Manual may help you. Some of the information has been covered in posts by other members.

 

[commodoredave]

Thermofans are primarily switched on/off from the coolant temp sensor but the AC system will also trigger the fans depending on the system pressure. Road speed is also a factor, generally above a certain speed the thermofans won't turn on ( about 50km/h IIRC).

The high speed fan is triggered directly from the PCM, the low speed fan is triggered from the BCM via the Canbus system.

Fans turn on/off at the following temps.
View attachment 254353

Notice U have tuner pro. Do you also have EFILiveV4 and AED from Envyous? Asking cuz each peice of scan software gives off different fault codes. AED scan=no fault codes, Tuner pro = 2 fault codes and EFI live says 7 fault codes. all scans done on same day with no driving in between

 

[Immortality]

No I only use tunerpro.

 

[commodoredave]

No I only use tunerpro.

What are your thoughts on tunerpro in terms of accuracy and reliability? The discovery that each differnt scanner I have tried reads different fault codes on the same car only minutes apart is confusing. If an experienced comoidore hand like you have settled on tunerpro it follows is must have been useful in car maintenance. Does a tunerpro user manual exist anywhere?

 

[Immortality]

I use Tunerpro because I do a little tuning work here and there.

I don't think there is an actual user guide as Tunerpro is just the platform, how accurate it is comes down to the files people create to use with tunerpro and seeing as most of this is freeware you are never 100% sure it's totally accurate but for the most part as far as I know it should be.

The stuff from Envyous Customs should be good I would think, Tazzi has put a lot of effort into it including some collaboration with the guys who also do some of the Commodore stuff for Tunerpro.