Case IH 2416 – Transmission Control Unit (TCU) or Central Control Unit (CCU): Medium / reverse range synchronizer potentiometer - voltage too low

This code indicates that the voltage signal returning from the potentiometer—which monitors the physical position of the medium/reverse range synchronizer gear—has dropped below the acceptable calibrated range. This usually points to a failed sensor, a short to ground in the wiring harness, or a loss of the 5V reference signal.

• Optum
• Puma 115
• Puma 125
• Puma 140
• Puma 155
• Puma 165
• Puma 180
• Puma 195
• Puma 210
• Puma 225
• Maxxum 100
• Maxxum 110
• Maxxum 115
• Maxxum 120
• Maxxum 125
• Maxxum 130
• Maxxum 140
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• MXU 100
• MXU 110
• MXU 115
• MXU 125
• MXU 130
• MXU 135
• T7.165
• T7.175
• T7.190
• T7.210 Sidewinder II

1. 1

   Inspect Connectors: Check the medium/reverse range synchronizer potentiometer connector (e.g., connector X-667) and the CCU connector (e.g., X-094). Ensure they are fully seated, not damaged, and that the pins are tight and free of corrosion.

2. 2

   Check 5V Reference: Disconnect the potentiometer connector. Turn the ignition switch to the ON position and use a multimeter to measure the voltage at the harness side. You must verify that the 5-Volt reference signal from the CCU is present.

3. 3

   H-Menu Diagnostic Test: If the tractor is operational, enter the H-Menu diagnostic mode. Run the 'SYNCHRONIZER POTENTIOMETER CHECK' to observe the live operation of the synchronizer. The display should indicate the potentiometer movement as a percentage (e.g., approx. 25% for forward, 75% for reverse). If the reading is dead or erratic, the sensor is likely faulty.

1. 1

   Preparation

   Turn the ignition switch OFF and disconnect the battery.

2. 2

   Access the Sensor

   Locate the medium/reverse range synchronizer potentiometer on the side of the transmission housing. Note: On mid-sized CNH tractors like the Puma, accessing the transmission range packs and sensors often requires removing the right rear wheel for clearance.

3. 3

   Removal

   Disconnect the electrical harness from the potentiometer. Remove the retaining hardware and carefully pull the sensor straight out of the transmission housing.

4. 4

   Installation

   Install the new potentiometer. Ensure the blocked hole configuration or alignment tabs mate perfectly with the synchronizer shaft to prevent damage and ensure accurate position monitoring. Secure the mounting hardware and reconnect the electrical harness.

5. 5

   Reassembly

   Reinstall the right rear wheel (if removed) and reconnect the battery.

6. 6

   Calibration

   You must perform a transmission calibration using the tractor's electronic management system. This teaches the CCU the new minimum and maximum voltage limits of the replacement potentiometer.