u1140 lost communication with active exhaust valve

OBD2 Code: U1140

Description: Lost Communication with Active Exhaust Valve

Definition: This code indicates that the vehicle’s control module has lost communication with the active exhaust valve. The active exhaust valve is responsible for controlling the flow of exhaust gases to optimize performance and sound. A loss of communication can result in improper functioning of the exhaust system, potentially affecting vehicle performance and emissions.

: Lost communication with active exhaust valve
Severity: Moderate

Common Causes

U1140 – Lost Communication with Active Exhaust Valve

Common Causes:

• Faulty active exhaust valve
• Wiring or connection issues between the active exhaust valve and the ECM/PCM
• ECM/PCM software needs to be updated
• Faulty ECM/PCM

Common Misdiagnosis

Lost Communication with Active Exhaust Valve
Common Misdiagnosis: Replacing the active exhaust valve without checking for wiring issues or a faulty control module.

Common Diagnostic Steps

Lost Communication with Active Exhaust Valve

• Description: This code indicates a loss of communication with the active exhaust valve control module.
• Common Diagnostic Steps:
  1. Check for any additional codes that may indicate other issues in the communication network.
  2. Inspect the wiring and connectors between the PCM (Powertrain Control Module) and the active exhaust valve control module for damage or corrosion.
  3. Verify power and ground connections to the active exhaust valve control module.
  4. Use a scan tool to check for proper operation of the active exhaust valve during various engine conditions.
  5. If equipped, perform a continuity test on the CAN bus lines to ensure there are no breaks or shorts in the circuit.
  6. Update or reprogram the PCM if necessary, as per manufacturer guidelines.
  7. If all else fails, consider replacing the active exhaust valve control module after confirming it is faulty.