Vehicle ECU noise influencing Analog output from DAQ

[gooohestpoo]

Hi, 

I'm struggling for noise problem and needs your advice.

One ECU generates ground noise and this is connected the A power supply.

The DAQ system is connected the B power supply.

DAQ generate analog outputs for sensor simulation.
Due to the ground noise, the analog output signals are waving with the noise. 

Eventually, all sensor data is waving.

A power and B power grounds are common connected.(shorted)

How can I solve this? Need your fantastic experience and advice.

Thanks in advance.