VY S1 Aircon control

[Tre-Cool]

Does have one have the schematics for the VY series 1 manual ac controls & potentially the vz 6lt.

I re-gassed the ac today, but as im using an e38 ecu instead of the original ls1 ecu it doesnt have a physical pin like the ls1 ecu does for the A/C request to turn on, rather it gets it via canbus. (another problem that i have a solution for)

so i've resorted to connecting to ground to verify it's all working.

What im trying to work out is how does the AC button on the dash work, I'm guessing it's wired to the bcm, then the bcm tells the ecu to turn on ac relay.

However there is 2 pins on the BCM which both say AC Request. Is 1 to the button, then one is the output to ecu?

Connector1-19

RD/BK

762

A/C Request Signal

Connector2- 5

RD/WH

66

A/C Request Signal

[pman92]

Maybe both of them pins go to one side of the button each?

VY V6 definitely has the AC switch connected to BCM. The BCM sends the request to PCM via the ALDL bus chatter.

I would be pretty confident that VY V8 would work the same, except the BCM would be sending request to PIM on the ALDL bus, and the PIM would then pass the request onto PCM on the VPW bus. IE. There's not a wire running to the LS1 PCM for AC request as you say

[Tre-Cool]

ac request is actually a 12v signal, it's got a dedicated pin on the ecu so wouldnt be via vpw. but you could still be correct on the bcm to pim side of things.

bcm send signal out to pim, pim then sends 12v out.

[Tazzi]

well the VZ V6 and VZ 6.0L use ALDL to CANbus through the PIM which would carry the AC request?

[pman92]

I would say the dash button is a momentary switch (not on/off)
The BCM sees the pulse when you have your finger on it and turns AC request on or off. It would also remember if AC is on or off after ignition cycles etc.
The BCM would be sending this off over ALDL. There's no difference between a V6 or LS1 BCM or Climate Control module so that's the only logical answer.

The PIM must receive it, and as you say maybe the PIM has a wire that sends the signal to PCM.

But I think it's more likely done over VPW.
Not to say some Gen3 vehicles had the physical input pin connected (as in your truck diagram), or that you couldn't use the physical input pin. But in a factory LS1 VY I would be saying over VPW.

I'll have a look and confirm for sure there's no physical wire for AC request between PIM and PCM when I get a chance

[Tre-Cool]

i didnt manage to look at the original stock ls1 harness, so job for the tomorrow.

if there is a wire into the ls1 connector i'll trace it back.