Case IH 2325 – Transmission Controller: Mid speed sensor and output speed sensor swapped

The transmission control module is receiving speed signals that indicate the wiring connectors for the mid-range speed sensor and the output speed sensor have been plugged into the wrong sensors, or there is a wiring/sensor failure causing the signals to cross or mimic a swapped condition.

• Puma/Mid Range Magnum
• Magnum 180
• Magnum 190
• Magnum 210
• Magnum 230
• Magnum 235-340
• Magnum 250
• Magnum 255
• Magnum 285
• Puma 140
• Puma 165
• Puma 170
• Puma 185
• Puma 200
• Puma 210
• Puma 215
• Puma 225
• Puma 230
• Maxxum 120
• Maxxum 130
• Maxxum 140
• Maxxum 155
• Maxxum 175
• Maxxum 190
• Steiger 500
• Steiger 550
• Farmall Series

1. 1

   Inspect the wiring harness connectors at the transmission mid speed sensor and output speed sensor to ensure they have not been physically plugged into the wrong sensors.

2. 2

   Inspect the transmission wiring harness for damage, open circuits, or shorts to ground that could cause the signals to cross or fail.

3. 3

   Use the tractor's onboard diagnostic 'H Menu' (specifically the H9 - Voltmeter diagnostic menu) or an electronic diagnostic tool to monitor the speed sensor signals while the engine is running or the vehicle is driven.

4. 4

   Verify the resistance and operation of both sensors before replacing parts, as a single failed sensor can mimic a swapped condition.

1. 1

   Disconnect Power

   Always disconnect the battery before swapping electronic transmission sensors to avoid electrical shorts or module damage.

2. 2

   Locate the Sensors

   Locate the mid speed sensor and output speed sensor on the transmission housing. (Note: Location varies by transmission type; on some Maxxum models, there is one speed sensor on each side of the transmission).

3. 3

   Correct the Wiring (If Swapped)

   Disconnect the wiring harness from both sensors. Verify the wire colors and pinouts match the service manual. If they were installed backward, route the harness correctly and plug them into the proper sensors.

4. 4

   Replace Faulty Sensor (If Applicable)

   Remove the retaining bolt holding the faulty speed sensor. Pull the sensor straight out of the transmission housing. Lubricate the O-ring on the new sensor with clean transmission fluid. Install the new sensor into the housing and torque the retaining bolt to OEM specifications.

5. 5

   Clear Fault Codes

   Turn the key start switch ON. Access the tractor's onboard 'H Menu' (using the diagnostic connector tool). Use the HC menu to erase all stored error codes, or the H8 menu to clear stored calibration values and error codes by resetting the EEPROM.

6. 6

   Recalibrate

   Perform a transmission calibration procedure as outlined in the service manual to ensure the controller recognizes the new sensor inputs.