P0657 Code: Actuator Supply Voltage “A” Circuit/Open

Electronic sensors, actuators, and computer modules regulate the powertrain and various vehicle support systems. Actuators, in particular, are often responsible for moving vanes and valves. If the powertrain control module (PCM) notices that the voltage supply circuit to one or more actuators has a problem, on-board diagnostics (OBD) will log a P0657 trouble code.

What Does the P0657 Code Mean?

Diagnostic trouble code (DTC) P0657 stands for “Actuator Supply Voltage ‘A’ Circuit/Open.”

The PCM receives input from various sensors and switches. These inputs come in the form of electrical signals, which are then converted into output signals that help operate the system actuators. These electrical signals cause actuators to perform mechanical movements.

A problem with one or more actuators can cause the PCM to log a P0657 code, which, in this case, can refer to an actuator circuit designated as “A.”

Note: The definition of code P0657 might be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

What are the Common Causes of the P0657 Code?

• Wiring issues
• A failure of one or more actuators
• Transmission control module failure
• Powertrain control module failure

What are the Common Symptoms of the P0657 Code?

• Illuminated check engine light
• One or more actuators don’t operate properly, potentially leading to a variety of driveability problems

How to Diagnose the P0657 Code

DTC P0657 is a generic powertrain code that can be logged in vehicles with an OBD-II system. While this might be the case, keep in mind that the steps for diagnosis and repair can vary, depending on vehicle specifications. Some makes and models might require additional steps.

Diagnosing a P0657 code might require you to use a scan tool and inspect the affected system for signs of damage. If you’re not familiar with the task, it’s best to have your vehicle diagnosed by a trained professional instead. Otherwise, you can go ahead and do it yourself.

How to Fix the P0657 Code

Attempting to resolve a P0657 code can be a frustrating and confusing task if you lack the necessary tools and technical information. If done incorrectly, it might even result in further complications and heftier repair costs. If you’re not confident with your DIY skills yet, it’s best to go to the nearest auto repair shop and have a certified mechanic perform the necessary repairs. This will ensure that all steps and protocols are followed correctly.

But if you’ve had some experience in dealing with DTCs before, then you already know that there’s no such thing as an umbrella fix that will work for all makes and models. So before you work on your vehicle, make sure you’re equipped with vehicle-specific repair information like those from Chilton or an ALLDATA subscription.