CACB : Communication Error B

To avoid serious injury follow all warnings and instructions in the manual. Wear appropriate personal protective equipment.

This error applies to Reactor E-30i/E-XP2i only.


Insert a system token into the missing GCA module and cycle the power. Wait until the red light on the module stops flashing before removing the token.


Ensure the dial on the module is in the correct position: 0 for hose, A for boost A, B for boost B.


  • Green light on each module should be lit. If green light is not lit, check to make sure each CAN cable connection is not cross threaded and is tight.
  • Verify the power supply is outputting 24 V dc. If not, check power supply wiring. If wiring is okay, replace the power supply.

Check the CAN cables running between GCA modules.  Check for cross threading and tighten if needed. If the problem still persists, grasp the cable near the connector, move it around, and watch the flashing yellow light on the GCA modules. If the yellow light stops flashing, replace the CAN cable.