* First, verify connections, The stepper pins are on EC18 (not EC36)

** the default setting assume the coils are between output stepper A-B (EC18/4-EC18/10) and C-D (EC18/5-EC18/11) - seems like the connection is correct (just verify) and the D,A,C,B Stepping sequence in the vemslog below seems to match this (or C,A,D,B if direction reversal is needed). Note that A,C,B,D or A,D,B,C are more common settings for the A-B and C-D coil wiring (but effectively same result).

** if the coils are accidentally connected between stepper outputs A-D and B-C (which is apparently not the case here, just the texts on the drawing are confusing): It can be configured that way too (swap the top 2 entries in the "Stepping sequence"), but you have to watch out for this.

* measure resistance of the 2 coils inside the stepper motor. Take note of the pair of pins.

* try VemsTune iac-lock feature

** if it reacts to iac-lock (higher and lower positions: take note if the direction is correct or reversal needed), than reference position and tuning can be started

** if it does not react to different iac-lock positions, disconnect the stepper motor and do output tests for all 4 outputs. Measure with DVM (20V DC mode) from GND and also from 12V (as a base).

* document your measurements exactly (here is fine)