Case IH P47 – Electronic Management Unit (EMU) / Transmission Controller: CAN CCVSS Message, Data Valid But Above Normal Range

The CCVSS (Cruise Control Vehicle Speed Sensor) monitors the tractor's speed for the cruise control and transmission systems. This code triggers when the sensor transmits a signal over the Controller Area Network (CAN) bus that is in a valid data format, but the actual speed value reported is impossibly high or exceeds the normal operating parameters programmed into the system.

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190

1. 1

   Check for swapped connectors: Verify the transmission mid-speed sensor connector (C037) and output speed sensor connector (C038) were not accidentally swapped during maintenance.

2. 2

   Inspect the wiring harness between the CCVSS and the EMU for chafing, bare wires, or pinch points that could cause a short to voltage.

3. 3

   Test sensor voltages: Disconnect the sensor and verify it receives the correct +5V reference voltage and a solid ground from the controller.

4. 4

   Clear the code via the tractor's H-Menu or diagnostic tool and test drive to determine if the fault is hard or intermittent.

1. 1

   Prepare tractor for service

   Park the tractor on a level surface, engage the parking brake, turn off the engine, and disconnect the negative battery terminal.

2. 2

   Locate sensors

   Locate the vehicle speed sensors on the side of the transmission housing.

3. 3

   Verify cable routing

   Verify the routing of the sensor cables. If the mid-speed and output-speed connectors are swapped, disconnect them and plug them into their correct respective sensors.

4. 4

   Inspect CCVSS connector

   If the connectors are correct, disconnect the CCVSS connector. Inspect the pins for corrosion, moisture, or being pushed back into the housing. Clean with electrical contact cleaner if necessary.

5. 5

   Test wiring continuity

   Test the continuity of the CAN high and CAN low wires from the sensor connector back to the EMU harness. Repair any breaks or shorts.

6. 6

   Remove faulty sensor

   If the wiring is intact and the voltage is correct, the sensor itself has failed internally. Remove the retaining bolt holding the CCVSS in the transmission housing and pull the sensor out.

7. 7

   Install new sensor

   Lubricate the O-ring on the new speed sensor with clean transmission fluid, insert it into the housing, and tighten the retaining bolt to OEM specifications.

8. 8

   Reconnect components

   Reconnect the sensor harness and the battery.

9. 9

   Clear fault code

   Turn the key to the "ON" position. Enter the H-Menu (or use a diagnostic tool) to clear the stored t47 fault code.

10. 10

    Test drive

    Test drive the tractor, verifying that the speedometer reads accurately and the cruise control engages without triggering the fault code.