What is the P0657 fault codes? What is the description of the Actuator Supply Voltage “A” Circuit / Open fault code? How can you fix P0657 fault codes? What are the symptoms and causes for the P0657 fault code
What is the P0657 fault code? What does it signify?
Fault code P0657 means “Actuator Supply Voltage A” Circuit / Open . If the powertrain controller module (PCM), or any other control unit detects an interrupt in communication between two control modules, it is set. The code definition includes the “A” label. It refers to an area of the CAN (Controller Area Network), bus circuit, and not a specific circuit or cable. Depending on the application and vehicle make, the exact meaning of “A” may differ. Therefore, it is recommended to consult your vehicle’s manual for repair.
The vehicle’s CAN bus is a complex wiring harness which connects all sensors, electronics and control modules to one another and to the PCM. The system can be described as a network station in which all control modules are constantly communicating with one another. The command room for vehicle operation is the PCM.
Each control module cannot work alone. Any communication breakage between any control module or the systems it controls can affect other control modules and/or systems. Although it is possible to repair lost communication between sensors and control modules, you will most likely need to test the entire CAN bus system.
Depending on the application and vehicle make, the number of control modules can vary. Some applications can have up to 18 control modules, while other applications may require many more. Control modules that connect via the CAN bus typically include, but do not limit to:
- – Alternative fuel control module
- – Body Control Module
- – Anti-lock Brake Control Module (ABS).
- – Instrument cluster control module
- – Fuel injection control module
- – Turbo boost pressure control module
- – Anti-theft/security/alarm-control module
- – Cruise control module
- – Traction control Module
- – Stability control module
- Distance warning control module
- Climate control module
Multiple control modules may share a signal from the same sensor in certain applications. These modules receive, for example, the signal from the speed sensor.
- Motor functions can be managed by the PCM
- – To maintain vehicle speed by using the cruise control module
- – To the ABS controller module to activate the brakes.
- – To the distance controller module to maintain safe distance from other vehicles
This example shows the complexity of the CAN system. Although it is simplified, it does not detract from the complexity of the system. Each control module is programmed with a sequence of messages it should receive from the other control modules. A fault code is set when a particular control module doesn’t receive the expected signal or loses contact with other control modules. In some cases the check engine lamp will be activated. You should note that not all faults will instantly generate a fault code. Others may require multiple fault cycles before setting the code and lighting a warning lamp.
The transmission control module (TCM) may detect the P0657 fault code depending on the make and type of your vehicle. Transmission-related problems can sometimes trigger this code. This code may also be triggered if there are problems with the EVAP systems on certain European vehicles. To diagnose and repair the problem properly, consult the manual for your vehicle.
There are many models that are susceptible to the P0657 fault code, including Ford and Volkswagen, Pontiac. Fiat. Acura. Toyota. Jeep. Opel. Audi. Mitsubishi. Renault. Citroen. Dodge. Chrysler. Honda.
Notes:
Although P0657 is a common code, it’s also known as a generic code. “Actuator Supply Voltage A” Circuit / Open Manufacturers may have given different meanings to the code. Here are some examples of possible interpretations of the code. However, other meanings could exist.
Ford: This code indicates that some Ford models have lost some of their memory. Other models have this code that indicates a loss of communication between PCM and transmission shift solenoids.
Volkswagen / Toyota / Mitsubishi: This code P0657 is used to indicate a throttle actuator failure and throttle control motor motor failure. On some VW models, it may also indicate a loss of communication between PCM and any or all transmission shift solenoids.
Honda / Acura: These applications refer to P0657 as the loss of communication between PCM and any or all transmission shifting solenoids. Acura adds complexity to the equation by identifying this code on certain models. as “Air/Fuel Ratio Sensor Relay Circuit Malfunction” .
What is the P0657 Fault Code and Why Does It Happen?
Below are some reasons to set fault code P0657:
- – Any wires or connectors that are damaged, melted and corroded.
- – PCM: Open or short circuit
- – Short or open circuit between two control module
- Voltage spikes can cause damage to electronic circuits
- Low battery voltage or system voltage can cause damage to sensitive circuits
- – Water ingress into control modules and wiring harnesses
- – Defective sensor (when any sensor fails the fault code is also set).
- – Short or open circuit between engine sensors, PCM
- – Defective transmission shift solenoids
- – A PCM that is not working properly or has to be reprogrammed (rarely).
What are the symptoms for P0657 Malfunction Codes?
The most common symptoms are a set fault and activated check engines lights. Other symptoms are often specific to make and models and depend on the fault location in the CAN. These problems can be caused by the control module’s loss of communication. The solution is to see the whole picture and not just the individual parts.
These symptoms may be present in vehicles with code P0657.
- – Illumination at the check engine lights
- – Other fault codes can be set
- – The engine might not start or run well.
- – Fluctuations at idle speed
- – Misfires or power loss during acceleration
- Problems with automatic transmission shift
- Transmission stuck in any gear
- – PCM enters failsafe mode and limits engine power
- – Increased fuel consumption
How to Fix the P0657 Fault Code
Some repairs that could resolve the P0657 fault code are:
- – Repair of damaged, corroded and snapped connectors or cables on the CAN bus.
- – Checking and tightening the PCM connectors, ground wires, and/or ground wires
- – Repair of or replacement of the PCM harness
- – Charging the battery or replacing it
- – Check the charging system, and make repairs if necessary
- – Repair of damaged sensors
- – Repair of damaged transmission shift solenoids (depending upon application).
- – Repairing poor electrical connections and cables, as well as replacing solenoids and transmission cables.
- – Reprogramming the PCM or replacing it (rarely).
How serious is the P0657 Fault code?
Depending on the control module that is losing communication, the severity level of the P0657 code could vary. It can cause a variety of serious and potentially dangerous issues. Fault code P0657 must be identified and fixed as soon as possible.
