In short, SCL-SCU pairing in VDash is for non-keyless-entry P3 car, not mentioned anywhere in VDash documentation.

I will create support ticket to request refund.

@T5-T6-Schnappi
You are absolutely right.

The SCU-SCU/SCL-SCU pairing in VDash is actually for earlier P3 models with key fob slot position to the left of the push button.

My car is slightly newer P3, the key fob slot position is bottom of the push button.

In my country only the authorize Volvo dealer can program new IAU. Paid VDash for nothing.

Do you think this confusion will allow for refund?

do you know about read error: 1215 above?

@T5-T6-Schnappi

ECM-U016700 Lost Communication With Vehicle Immobilizer Control Module.

This is what originally shown when it first happen.

I checked all fuses, they're ok.

I also did continuity test from all wirings from SCL, IAU, Push button switch to CEM. Also ok.

virgin SCL wont pair to SCU.

virgin IAU pairing produced error, as above.

I just ordered new push button switch, but I dont know if its really programmable, but this site here tells it is. https://www.ipdusa.com/products/13636/Start-Stop-Engine-Button-Switch-Mid-P3-Genuine-Volvo-31456644-31318791-31394113

failure to pair new virgin IAU

Ignition switch. Design is simple, like a mechanical switch, but there is small circuit board inside.

'Steering lock try start again.'

My car is immo locked with this message on display.

I bought a new SCL but unable to pair via Vdash, the command wont execute.

So I bought a new IAU (immobilizer antenna unit) thinking this is the SCU, but even a new virgin unit produce error during pairing, saying the SCU already programmed.

My v40 is P3 keyless model, and its SCU slightly different than previous generation volvos, in one picture, it shown the SCU as a combination of 3 parts; a push start ignition switch, a plastic frame and an IAU (immobilizer antenna unit).

But in the official wiring diagram, the SCU and IAU are two different parts, as connected in the car starting circuit.

Please advice whether the ignition switch itself is the SCU that requires pairing to the SCL. And whether the IAU also requires programming.

Anyone?