This was not so much reverse engineering as a LOT of Google searching.
I came across the following information about the pump.
It is a CWA-50 .
The motor is a 12 v induction motor.
They are also used in the inter coolers of various vehicles.
If interest in the AZD schematic, and the below spec sheet, the line to the pump is labelled PWM.
I finally came across a manufacturers data sheet for the unit in German. Translated Here.
Importantly, if you connect the PWM pin to +12v, the pump will run continuously at maximum.
