how to fix a U0140 code on Toyota Tacoma N300 (2016-Present)

• •Check engine light illuminated
• •Inability to start the vehicle
• •Erratic behavior of electrical components (e.g., windows, lights)
• •Loss of power to certain systems (e.g., climate control)
• •Diagnostic scanner shows U0140 code or other related communication errors

1. 1Use an OBD-II scanner to confirm the U0140 code and check for any additional codes.
2. 2Inspect the vehicle’s fuse box and check for blown fuses related to the ECM and communication modules.
3. 3Examine the wiring harness for the ECM and affected modules for any signs of damage, corrosion, or loose connections.
4. 4Perform a visual inspection of ground connections to the ECM and other control modules.
5. 5Check the battery voltage and ensure it is within the proper range (12.4 to 12.7 volts) to rule out power issues.
6. 6Clear the codes and attempt to restart the vehicle to see if the issue persists.

After completing the repair, verify that the issue has been resolved:

• ✓Test the affected component to ensure it functions correctly
• ✓Check for any error codes or warning lights
• ✓Monitor the vehicle for a few days to ensure the issue does not recur

To prevent this issue from occurring again:

• •Follow the manufacturer's recommended maintenance schedule
• •Address warning signs early before they develop into major issues
• •Use quality parts and fluids recommended for your vehicle
• •Keep detailed records of all repairs and maintenance

• •OBD-II scanner
• •Multimeter
• •Wire strippers
• •Fuse puller
• •Soldering iron (if needed)

• •Replacement fuses (if necessary)
• •Electrical connectors and wire (if repairs are needed)