U2140 – Module Communication Loss Detected

The ODBII code U2140 indicates that there is a communication loss between modules in the vehicle’s network, suggesting that one or more electronic control units (ECUs) are unable to communicate with each other.

The severity of ODBII code U2140 is generally considered moderate to severe.

Common Causes For: U2139 Lost Communication with the Steering Angle Sensor Module.

• Faulty wiring or connectors
• Failed control module
• Corrupted software or firmware
• Poor ground connections
• Intermittent electrical issues
• Low battery voltage
• Communication network issues (e.g., CAN bus problems)
• Damaged or corroded pins in connectors
• Faulty or damaged sensors
• Aftermarket modifications or installations affecting communication

Common misdiagnosis for U2140 U2140: “Module Communication Loss Detected”

• Faulty wiring or connectors
• Defective control module
• Battery or power supply issues
• Software or firmware glitches
• Intermittent communication issues
• Grounding problems
• Incorrectly configured or programmed modules
• Faulty sensors or actuators

Common Troubleshooting Steps

The OBD-II code U2140 indicates a “Module Communication Loss Detected,” which typically means that there is a communication issue between the vehicle’s control modules. Here are some common troubleshooting steps to diagnose and resolve this issue:

• Check for Other Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Sometimes, multiple codes can provide more context for the issue.
• Inspect Wiring and Connectors:
• Visually inspect the wiring and connectors associated with the affected modules. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the ground connections, as poor grounding can lead to communication issues.
• Check Power Supply:
• Ensure that the affected modules are receiving the proper voltage. Use a multimeter to check the power supply to the modules.
• Verify that the fuses related to the communication network are intact.
• Test Communication Lines:
• Use a scan tool to check the communication lines (CAN bus, LIN bus, etc.) for proper operation. You can use a scope or a specialized tool to monitor the data signals.
• Look for any interruptions or short circuits in the communication lines.
• Inspect Modules:
• If possible, check the affected module for any signs of failure. This may include checking for water intrusion, physical damage, or internal faults.
• If you have access to a known good module, you can swap it out to see if the problem persists.
• Reset Modules:
• Sometimes, resetting the modules can clear temporary communication issues. Disconnect the battery for a few minutes or use the scan tool to clear the codes and see if they return.
• Check for Software Updates:
• Verify if there are any software updates available for the vehicle’s modules. Sometimes, manufacturers release updates to fix communication issues.
• Consult Wiring Diagrams:
• Refer to the vehicle’s wiring diagrams to understand the communication network and identify any potential issues in the circuit layout.
• Perform a Network Test:
• If you have access to advanced diagnostic tools, perform a network test to check the integrity of the communication network and identify any faults.
• Seek Professional Help:
• If the issue persists after performing the above steps, it may be necessary to consult a professional technician or a dealership with specialized diagnostic equipment. By following these steps, you should be able to identify and resolve the communication loss indicated by the U2140 code.