Case IH tAF – Transmission Control Module (TCM): Vehicle CAN Chip, Data Incorrect

The controller has detected that the data being processed or received by the vehicle's internal Controller Area Network (CAN) chip is invalid, corrupted, or incorrect. This points to a communication failure on the CAN bus network or an internal hardware failure of the CAN chip within the module itself.

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

1. 1

   Check for accompanying CAN bus fault codes (tB0, tB1, tB2, tB3) that might indicate a wiring issue rather than a failed chip.

2. 2

   Inspect the wiring harness and connectors leading to the Transmission Control Module for corrosion, pushed-out pins, or moisture.

3. 3

   Test the CAN bus network for proper resistance (typically 60 ohms across CAN High and CAN Low with the battery disconnected) and verify that there are no shorts to ground or power.

4. 4

   Ensure the tractor's battery and charging system are providing stable voltage, as voltage drops can cause CAN chips to process data incorrectly.

1. 1

   Disconnect Power

   Disconnect the tractor's battery before servicing any electronic modules to prevent electrical spikes.

2. 2

   Remove the Module

   Locate the Transmission Control Module (ECU) and carefully disconnect the multi-pin wiring harnesses. Remove the mounting hardware and extract the module.

3. 3

   Install the New Module

   Mount the replacement or remanufactured Transmission Control Module and securely reconnect the wiring harnesses.

4. 4

   Reconnect Power

   Reconnect the tractor's battery.

5. 5

   Perform Transmission Calibration

   Hold the High and Low range buttons simultaneously and start the engine. Wait for 'CAL' to appear in the transmission display, then release the buttons. Set the engine speed to 1200 RPM (± 100 RPM). Follow the on-screen prompts to cycle through the clutch and synchronizer calibration steps until complete.