Bosch Dishwasher - top arm is not spinning

Bosch dishwasher model SHE68R55UC

Upper arm is not spinning and soap pods are barely dissolving.

The soap compartment door is opening at the correct time. Took apart both upper and lower arms and cleaned out some gunk that was inside the arms. Also cleaned out floor drain but still no improvement.

Saw advice online to add water into the DW in case the water inlet valve was faulty. Tried that as well but still no improvement.

Currently suspecting it the impeller is faulty. Placed an order for the part. In the meantime, is there some way to test the impeller or another part that could be the culprit? Also, is there a way to get our model to display error codes? Found instructions for several Bosch models but the names of the buttons don’t match up with my model.

Thank you