• Check Engine Light is on
• Engine may not start
• Reduced fuel efficiency
• Faulty ECM/PCM
• Damaged wiring or connectors
• Faulty CAN bus network
ECM: Engine Control Module
PCM: Powertrain Control Module
CAN bus: Controller Area Network bus, a vehicle communication network
• U0100
• U0140
This code means that your car's computer is having trouble talking to one of the parts that helps control the engine. It's like when your phone can't connect to the internet.
The U0641 code indicates a loss of communication with the Engine Control Module (ECM) or Powertrain Control Module (PCM).
U0641 is a communication fault code that signifies the loss of communication with the ECM/PCM. This can occur due to issues with wiring, connectors, or the module itself, impacting the vehicle's ability to manage engine functions.
• Check for other codes that may indicate a specific issue.
• Inspect the wiring and connectors for damage or corrosion.
• Test the CAN bus network for proper communication.
• Repair or replace damaged wiring or connectors.
• Replace the ECM/PCM if it is faulty.
• Ensure the CAN bus network is functioning correctly.
• OBD-II scanner
• Multimeter
• Wire repair tools
$200 - $1000
Moderate
• Chevrolet Silverado
• Ford F-150
• Toyota Camry
• Regularly inspect and maintain vehicle wiring.
• Ensure connectors are clean and secure.
• Avoid exposure to moisture in electronic components.
Communication Issue
• Have a professional diagnose the issue.
• Avoid driving the vehicle if engine performance is affected.
• Regular maintenance can prevent such issues.
Check with your vehicle manufacturer for warranty coverage on ECM/PCM components.
This code has been associated with communication issues in vehicles since the introduction of CAN bus systems.
Moderate – It is advisable to address this issue soon to prevent potential engine performance problems.
Driving with this code may lead to engine performance issues, which could be unsafe.
• Vehicle must be in a safe location.
• Ensure the ignition is off before inspecting wiring.
The ECM/PCM is typically located in the engine compartment or under the dashboard.
Q: Can I drive with a U0641 code?
A: It's not recommended to drive with this code, as it may affect engine performance.
Q: How do I clear a U0641 code?
A: Fix the underlying issue and use an OBD-II scanner to clear the code.
