ACU - Armrest Controller Unit: Communication Lost

John Deere Heavy Equipment Warning Communication

Model: John Deere 6155R Tractor | Code: ACU-01

Applicable Systems
9R Tractor

Symptoms

Armrest control functions not responding; seat/hitch control from armrest panel inoperative.

Possible Causes

  • ACU CAN bus communication loss
  • ACU connector loose or corroded
  • ACU internal controller failure

Troubleshooting Steps

  1. Step 1: Check ACU connector at armrest base
    Connector fully seated, no corrosion
  2. Step 2: Verify CAN bus communication to ACU
    ACU responds to Service Advisor query
  3. Step 3: Check ACU power supply fuse (15A)
    Fuse intact, +12V at ACU
  4. Step 4: Replace ACU if no communication
    New ACU communicates on CAN bus
  5. Step 5: Clear codes via Service Advisor and calibrate armrest
    All armrest functions operational

How to Reset

Clear via John Deere Service Advisor after repair.

Common Replacement Parts

  • ACU Module P/N: RE284091

Frequently Asked Questions

  • Q: What does the ACU control?

    Armrest Controller Unit manages seat position, hitch height, and armrest-mounted switch functions on John Deere tractors.

Related John Deere Fault Codes

Source: johndeerefaultcodes.com

Category: Heavy Equipment