Case IH 1991-03 - UCM – UCM: Rear Pilot Head #7 - Supply Voltage High

The Rear Pilot Head #7 is reporting a supply voltage high condition. This means the voltage signal returning to the controller is above the upper threshold limit (e.g., greater than 4.8V on a 5V reference circuit, or shorted directly to a 12V power source). A shorted pilot head can also pull down or 'kill' the CAN Bus communication network.

• MAGNUM AFS Connect
• Steiger / Quadtrac Series: 350, 370, 400, 420, 450, 470, 500, 550, 580, 600
• Puma Series: 165, 180, 185, 195, 200, 210, 220, 225, 240
• Optum Series: 270, 300
• Magnum Series: 210, 280
• Maxxum Series: 120, 130, 140, 155, 175, 190

1. 1

   Isolate the CAN Bus: Unplug the #7 pilot head. If the rest of the remote valves come back online and CAN Bus communication is restored, the pilot head itself has an internal short and is faulty.

2. 2

   Inspect the wiring harness and connector at the #7 pilot head for damage, corrosion, or a short circuit to a power supply voltage.

3. 3

   Ensure that the cable harness connections have been made correctly and are fully seated.

1. 1

   Removal

   Disconnect the electrical harness from the faulty #7 pilot head and unbolt the assembly from the rear remote valve block.

2. 2

   Installation

   Install the new pilot head valve assembly and reconnect the wiring harness.

3. 3

   Calibration

   An EHR valve calibration is strictly required when installing a new valve pilot head. Access the 'H Menu' (or HK Menu) on the tractor's ADIC/display by depressing the 'menu' key. Navigate to Channel 1 (Valve Calibration). Note: This procedure requires the use of special dealer tools: a pressure transducer (Tool #380001903) and a jumper harness (Tool #84148258) connected to the test point.

4. 4

   Software Verification

   If the error code reoccurs after calibration, download the correct level of software to the module and re-perform the calibration procedure.