John Deere 002049.09 – TIQ: TIQ CAN BUS Message Fault

A communication failure has been detected on the Controller Area Network (CAN) bus, specifically an abnormal update rate or loss of messaging from the Main Control Module (Transmission Control Unit or TIQ). This breakdown in data exchange between the TIQ and other electronic control units prevents systems from communicating properly and can lead to operational disruptions.

• 6J
• 6M
• 6R
• 7R
• 8R

1. 1

   Restart the tractor to see if the code clears, or perform a cold boot by disconnecting the battery for a period to reset all controllers

2. 2

   Check fuses related to the electronic control units (such as F6, F22, F35, and F45, depending on the tractor model)

3. 3

   With power off, measure resistance between the CAN High (yellow wire) and CAN Low (green wire) pins at the diagnostic connector. A healthy bus reads approximately 60 ohms; a reading of 120 ohms suggests a missing or faulty terminating resistor

4. 4

   With power on, check the voltage of the CAN lines. CAN High to ground should be 2.5 to 3.0 VDC, and CAN Low to ground should be 2.5 to 2.0 VDC

5. 5

   Visually inspect the CAN bus wiring harness for chafing, corrosion on connectors, or loose connections, paying close attention to the wiring leading to the TIQ controller

6. 6

   Perform a wiggle test on the harness while monitoring the system to pinpoint loose connections

7. 7

   Unplug controllers one at a time from the CAN bus to identify if a specific faulty unit is disrupting communication

1. 1

   Access Diagnostic Trouble Codes

   Use the tractor's onboard diagnostic display or a diagnostic scanner to confirm the presence of the 002049.09 fault code and any other related codes.

2. 2

   Inspect CAN Bus Connections

   Based on the tractor's wiring diagram, locate the TIQ controller and inspect its connectors for corrosion, damage, or loose pins. Also, inspect the connections at the terminating resistors.

3. 3

   Test Terminating Resistors

   Locate and test the CAN bus terminating resistors. There are typically two 120-ohm resistors on the network. If one is faulty, replace it.

4. 4

   Isolate the Faulty Component

   If the wiring and terminating resistors are in good condition, use a John Deere service advisor tool or an advanced diagnostic scanner to isolate the malfunctioning unit on the network.

5. 5

   Replace Faulty Components

   If the TIQ controller is determined to be the cause of the fault, replace it. After replacement, the new controller may need to be programmed by a certified John Deere technician.