Case IH 2268 – ZDC: Vehicle speed greater than 10.0 km/h in neutral with engine speed below lubrication limit

The tractor is coasting or rolling at a significant speed in neutral, but the engine RPM is too low to drive the transmission's hydraulic pump at a sufficient rate. This creates a critical condition where the transmission components are spinning rapidly without adequate lubrication, which can lead to severe mechanical damage.

• Steiger T4B
• Case IH Steiger CVT / Rowtrac CVT
• Case IH Magnum CVT
• Case IH Puma CVX / CVT
• Case IH Maxxum CVX

1. 1

   Confirm with the operator if the tractor was being coasted down a hill in neutral with the engine at idle (operator error)

2. 2

   If the tractor was not moving, check the Vehicle Speed Sensor and Engine Speed Sensor for erratic signals or wiring harness shorts

3. 3

   Verify that the ZDC module is receiving accurate speed data from the VCM/UCM via the CAN bus

1. 1

   Address operator error

   If the code was operator-induced, no repair is necessary beyond clearing the code and instructing the operator not to coast in neutral.

2. 2

   Locate Vehicle Speed Sensor

   If a sensor is at fault, locate the Vehicle Speed Sensor on the transmission output shaft.

3. 3

   Inspect wiring harness

   Inspect the wiring harness for chafing, corrosion, or pin damage at the sensor connector and the ZDC module connector.

4. 4

   Test and replace sensor

   Replace the sensor if it fails a resistance/continuity test.

5. 5

   Clear codes and test-drive

   Clear the fault codes via the Case IH diagnostic tool and test-drive to ensure the code does not return.