Case IH 2609 (191.13) - DEC – Engine Control Module (ECM) or Transmission Control Unit (TCU): Transmission Output Shaft Speed Signal Missing or Not Available

The control module is not receiving the expected signal from the transmission output shaft speed sensor. The signal is missing, not available, out of calibration, or has an abnormal frequency, pulse width, or period.

• MAXXUM T4E
• Magnum series (180, 225-340, 7110-8950)
• Steiger series (420 RowTrac)
• Maxxum series (100-140)
• Farmall series (60A, 95U-115U)
• Axial-Flow series (7010, 7120, 8010, 8120, 9010, 9120)

1. 1

   Inspect the transmission output speed sensor(s) and the wiring harness for signs of physical damage, contamination, or metallic debris on the sensor's magnetic pickup.

2. 2

   Check the wiring harness for damage, corrosion, or loose connections at the sensor and the ECM/TCU.

3. 3

   Using a multimeter, perform continuity tests on the wiring from the sensor to the ECM to ensure proper electrical flow.

4. 4

   Verify the sensor's power supply and ground circuits, checking for a stable 5-volt reference (where applicable).

5. 5

   Use diagnostic software to verify ECM data, check for active SPNs, and ensure the transmission calibration values are valid.

1. 1

   Power Down

   Turn off the machine and disconnect the battery to prevent electrical shorts.

2. 2

   Locate the Sensor

   Locate the Transmission Output Speed Sensor on the transmission housing (often located on the rear bearing cover or rear axle housing).

3. 3

   Disconnect

   Carefully unplug the electrical connector from the sensor.

4. 4

   Remove

   Remove the retaining bolt/nut and carefully extract the sensor from the transmission case.

5. 5

   Clean

   Clean the mounting port and inspect the internal tone wheel teeth (if visible) for damage.

6. 6

   Install

   Insert the new sensor (ensure any O-rings or seals are properly seated) and tighten the retaining hardware to OEM torque specifications.

7. 7

   Reconnect

   Reconnect the electrical wiring harness.

8. 8

   Clear and Test

   Reconnect the battery, use a diagnostic tool to clear the 2609 (191.13) fault code, and perform a test drive to verify the transmission shifts correctly and the code does not return.