John Deere 1231.12 – TEC (Tractor Equipment Control Unit): Communication System, TEC Implement CAN Message Overflow / Vehicle CAN BUS, High Error Rate

The CAN bus is experiencing a high error rate or message overflow. The controller is receiving too many messages, corrupted data, or conflicting signals, which exceeds the CAN error limit and disrupts communication across the network.

• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6145J
• 6165J
• 6180J
• 6205J
• 6230
• 6330
• 6430
• 7630
• 7730
• 8245R to 8400R
• 9230
• 9330
• 9430
• 9530
• 9630
• E300LC
• E360
• E360LC

1. 1

   Cycle the power by placing the tractor in park, shutting off the engine, and cycling the key switch to reset communication messages

2. 2

   Disconnect any implements plugged into the rear ISOBUS/Implement connector to isolate the implement

3. 3

   Inspect the ISOBUS implement connector at the rear of the tractor for dirt, moisture, corrosion, or bent pins

4. 4

   Use a multimeter to check the CAN bus termination resistors (should read approximately 60 ohms with battery disconnected) and check CAN High and CAN Low lines for shorts

1. 1

   Clear Active Codes

   Turn the key switch off, wait 30 seconds, and turn it back on. Check the CommandCenter or diagnostic display to see if 001231.12 returns as an active code.

2. 2

   Disconnect Implements

   If the code is active, unplug the implement from the tractor's ISOBUS receptacle. If the code goes away, repair the implement harness or update the implement's software. If the code remains, the fault is on the tractor side.

3. 3

   Clean and Inspect Receptacle

   Thoroughly clean the tractor's ISOBUS receptacle. Apply dielectric grease to prevent moisture intrusion, which can bridge CAN lines and cause high error rates.

4. 4

   Inspect the Wiring Harness

   Trace the wiring harness from the implement connector back to the TEC. Look for chafed wires, pinched harnesses, or loose ground connections. Repair any damaged sections of the harness.

5. 5

   Software Update / Module Replacement

   If the wiring and connectors are perfectly intact and the CAN bus resistance is correct, the TEC itself may be failing or require a software flash. A John Deere dealer will need to connect Service ADVISOR to re-flash the TEC or program a replacement module.