New Holland 4193 – Armrest Controller (ARU) / Vehicle Controller / ECM: Rear Remote No.4 No Communications

The main vehicle controller has lost all CAN bus communication with the electronic module responsible for operating the No. 4 rear remote hydraulic valve. The system is unable to send commands to or receive feedback from this specific valve, rendering it inoperative. This is an electronic communication failure, not a hydraulic fault, triggered when the component fails to respond on the CAN bus network.

• T6 Series
• T6010
• T6020
• T6030
• T6040
• T6050
• T6060
• T6070
• T7 Series
• T7.170
• T7.220
• T7.235
• T.7.250
• T7.260
• T7.270
• Puma
• Maxxum
• T9 Series

1. 1

   Check battery and system voltage to ensure the battery is fully charged (approx. 12.6V) and the alternator is functioning correctly, as low voltage can trigger ghost communication codes.

2. 2

   Visually inspect the wiring harness leading to the #4 remote valve stack for chafing, corrosion, pinched wires, or rodent damage, paying close attention to the connector at the valve.

3. 3

   Perform a swap test by exchanging the wiring connectors between the faulty remote (#4) and a working remote (e.g., #2 or #3) to see if the fault code follows the valve module or remains with the tractor wiring.

4. 4

   With tractor power OFF and battery disconnected, perform a CAN bus termination resistance check at the tractor-side harness connector (should measure approx. 60 ohms between CAN High and CAN Low; ~120 ohms suggests a missing resistor or broken wire, while other values indicate a short or faulty module).

5. 5

   With tractor power OFF, check wiring integrity by measuring resistance to ground from the CAN High and CAN Low pins (should read as a very high resistance or open circuit; a low reading indicates a short to ground).

6. 6

   With tractor power ON, carefully back-probe the connector to measure CAN bus DC voltage (CAN High should be 2.5V-3.0V; CAN Low should be 2.0V-2.5V; incorrect voltages point to a wiring problem or faulty controller).

1. 1

   Isolate the fault

   Determine the point of failure based on diagnostic checks. If the swap test moves the fault to the other remote, the valve's electronic controller is faulty. If CAN resistance or voltage checks are incorrect, the issue is in the tractor wiring or another network module. If all wiring and power checks are good, the electronic controller on the #4 valve is the most probable cause.

2. 2

   Repair wiring harness

   If wiring faults (shorts, open circuits) were found during testing, repair or replace the damaged section of the harness. Clean all connectors, ensure they are free of corrosion, and verify secure connections, particularly at the main cab connection.

3. 3

   Replace remote valve section

   If the electronic control module on the valve is faulty, replace the valve section (slice). Disconnect electrical and hydraulic lines (cap lines to prevent spillage), unbolt the section from the stack (note they are often held together by long thru-bolts), install the new section ensuring O-rings are seated, re-torque bolts to manufacturer specification, and reconnect lines.

4. 4

   Calibrate the new valve

   Initiate the calibration procedure through the tractor's diagnostic menu in the instrument cluster or display monitor. This teaches the main controller the new valve's spool travel limits.