I met a CAN communication problem at my PWM RGB LED driver. I have a controller and a PWM RGB LED driver. The controller sends messege to the LED driver what the PWM duty cycles of the RGB channels be. The communication speed is 250kbps. I didn't see any communication problem in my previous LED Driver design. But after some improvement like changing the PWM driver circuit of MOSFETs, I realized that there are some commutation delay in my second design of the PWM driver. (Both pcbs are originally manufactured.) After debugging to the driver, it is seen that the CAN ESR register catches error frames. Because of this error frames, the driver responses the commands late. But interestingly, this error frames seen in some of my second design driver pcbs. Some are running with no errors. They both manufactured in same process and components. When I reduced the communication speed to 125, 100, and 50 kbps, the error frame did not appear in the debug. But testing in 80°C environment, the error frames appeared again.

I designed 2 different of 4-layer pcb of the driver. one is running without error frame. In hot environment (80°C), error frames were seen in second 4-layer pcb. 

I think that, this problem is because of the pcb layout. 800Hz PWM pulses on the MOSFETs may be affecting the message on the CAN Rx, Tx lines. 

Could it be a different reason than the layout?

What would you suggest I do for a solution?

Thank you in advance for your help.

My first pcb layout. There is no error frame in communication. 
[![enter image description here][1]][1]

My second pcb layout. Some of this pcbs error frames are occured in 250kbps CAN communication. 
[![enter image description here][2]][2]



My first 4-ayer pcb layout: Top copper is poured with DigitalGND. Inner layer 1 is DigitalGND plane. Inner layer 2 is PowerGND plane (MOSFETs Sources.) Bottom copper poured with PowerGND (all GND layers connected at Input Common Mode Choke's leg. )
[![enter image description here][3]][3]



My second 4-layer pcb layout. Layers are same as the first one.
[![enter image description here][4]][4]


  [1]: https://i.sstatic.net/GTjfm.png
  [2]: https://i.sstatic.net/yD7TR.png
  [3]: https://i.sstatic.net/Is3vR.png
  [4]: https://i.sstatic.net/FuKEP.png