Volvo electric power steering pump CAN bus control

[mck1117]

Well yeah... 80 amps... Why would you ever want to use it with a PDM...

80 amps, and it's designed to be permanently connected directly to the battery anyway

[Zeiss]

@Matthew: Awesome work! Congratulation!

Is there more info about this pump? Pressure for example...

Thank you.

[mck1117]

Is there more info about this pump? Pressure for example...

They aren't pressure regulated unless you give it a large volume demand, same as an engine driven pump. The spool valve in the rack normally passes fluid freely, so the pump is moving a large volume at low pressure. If you provide enough resistance to raise the pressure up to the pressure of the bypass valve in the pump, then it is pressure regulated. I think the bypass is at 1100 psi/75 bar or something. During normal steering I never hit the pressure bypass valve unless I hit the stop on the rack.

As far as I can tell, the "speed" limit set over CAN is in fact a current limit on the motor to impose an imaginary "pressure limit" (positive displacement pump so torque ~= pressure).

[Zeiss]

Hello Matthew,

thank you for the explanation. A colleague of mine is looking for an electric pump, as a replacement for the servo pump in the 8-series. Our servo pump has a maximum pressure of 120bar. The closest pump we know of is the one from a Mini with 105bar. It is not regulated, knows only on and off.

[nmstec]

Hello Matthew,

thank you for the explanation. A colleague of mine is looking for an electric pump, as a replacement for the servo pump in the 8-series. Our servo pump has a maximum pressure of 120bar. The closest pump we know of is the one from a Mini with 105bar. It is not regulated, knows only on and off.

02-05 Mini pumps are not on/off if supplied with LIN data. Working on that slowly. Recommend joining slack.

[Zeiss]

Here you can see the wiring diagram of an 10/2004 Mini Cooper S Convertible:

grafik.png (32.7 KiB) Viewed 13231 times

There is no LIN connected to it.

And here is the picture of the pump:

001.jpg (792.42 KiB) Viewed 13231 times

[nmstec]

What your diagram isn't showing you, is that the line going to alternator is also going to the ECU. It's linbus. Matt and I figured this out last week. Lin bus control for both pump and alternator.

image.png (26.71 KiB) Viewed 13230 times

I'll personally be getting and testing that pump within a month, as I am selling universal EPAS controllers.

[nmstec]

As per Andrey's permission, I now have a solution for running many different types of Steering Assist systems, with a wide variety of modes and functions.

https://www.nmstec.ca/product/psc/