Case IH t6 – Engine Control Unit (ECU) / Central Control Module (XCM): CAN AE Message (Torque Set point), Data Incorrect

A Controller Area Network (CAN) bus communication error indicating the torque setpoint data message (AE message) being transmitted across the CAN bus contains invalid or incorrect data. This usually points to a communication breakdown, electrical noise, or a wiring issue between the engine controller and the transmission/instrumentation controllers.

• MXM
• Case IH MXM Series
• MXM 120
• MXM 130
• MXM 140
• MXM 155
• MXM 175
• MXM 190
• Case IH MX / TG Series
• MX210
• MX230
• MX240
• MX255
• MX285

1. 1

   Check for accompanying codes (such as PTO twist sensor or engine torque/RPM sensor codes) to help isolate the root cause

2. 2

   Inspect CAN bus wiring (yellow and green data wires) for chafing, cuts, or corrosion, especially under the cab, near the engine block, or behind the instrument cluster

3. 3

   Measure CAN bus voltage using a multimeter; CAN High (yellow) and CAN Low (green) should both carry a baseline voltage of approximately 2.4V to 2.5V

4. 4

   Test the CAN bus terminators (near the engine controller and behind the instrumentation controller) by unplugging them and verifying they measure exactly 120 Ohms

5. 5

   Inspect the engine torque/RPM sensor and the PTO twist sensor for physical damage, loose mounting, or damaged phonic wheels

1. 1

   Disconnect Power

   Turn off the tractor and disconnect the battery to protect the sensitive control modules while working on the CAN bus.

2. 2

   Examine and Replace Terminators

   If the terminators test out of specification or are the older square 4-pin style, replace both of them with the updated 3-pin 'cap style' 120-ohm terminators.

3. 3

   Repair Harness Damage

   If any rubbed or stretched wires were found during the diagnostic phase (especially near the armrest plug or under the cab), cut out the damaged section, solder in new wire, and seal it with heat-shrink tubing.

4. 4

   Clean Connections

   Disconnect the main harness plugs at the Engine ECU and the Transmission Controller. Spray the pins with electrical contact cleaner, ensure no pins are bent or pushed back, and securely reconnect them.

5. 5

   Clear Codes and Test

   Reconnect the battery. Turn the key to the ON position, hold the 'diag' button to enter the menu, and clear the stored fault codes. Start the tractor and operate it to see if the code returns.

6. 6

   Module Replacement (Worst Case)

   If the wiring is perfect, terminators are new, and the code immediately returns, the Central Control Module (XCM) or Engine ECU may have an internal CAN transceiver failure and will need to be replaced and reprogrammed by a dealer.