Case IH tCE – PCU (Power Control Unit): 1 CAN Chip, Data Valid But Above Normal Range

The internal Controller Area Network (CAN) communication chip within the control module is receiving or transmitting valid data, but the signal voltage or data values are above the normal expected operating range. This typically indicates a hardware failure of the CAN chip inside the module itself, or a short to a high-voltage source on the CAN bus wiring.

• MXM
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• TM115
• TM125
• TM135
• TM150
• TM165
• TM175
• TM190

1. 1

   Check for associated codes (such as tCF or tD8) which might indicate a broader power supply issue or a direct short in the harness

2. 2

   Turn the key switch OFF, disconnect the battery, and inspect the electrical connectors at the PCU for faulty connectors, pushed-out pins, or corrosion

3. 3

   Perform a resistance/continuity test on the CAN bus wiring harness to check for shorts to a high-voltage source

4. 4

   Clear the error code and test the system for normal operation to determine if the fault is active or intermittent

1. 1

   Disconnect Power

   Ensure the tractor is turned off and the battery is disconnected to prevent electrical damage.

2. 2

   Repair Wiring

   If the diagnostic tests revealed a short to a high source in the wiring harness, repair the damaged section of the harness or replace the faulty connector.

3. 3

   Replace the PCU

   If the wiring and connectors test perfectly, the failure mode is a faulty PCU (the internal CAN chip has failed). Remove the mounting hardware for the Transmission Controller/PCU and install the replacement module.

4. 4

   Perform Calibration

   Because the microprocessor/controller has been replaced, you MUST perform the Transmission/EDC Calibration Set Up Procedures.

5. 5

   Clutch Calibration

   Start the engine and set the engine speed to 1200 ERPM. Enter the calibration mode (using the diagnostic switch special tool or by holding the High and Low range buttons, depending on the exact transmission). Calibrate the H1 Clutch and Synchronisers. The display will show 'CAL' and numbers will increase during the process until 'END' is displayed to signify completion.