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P0657 is a diagnostic trouble code (DTC) for "Actuator Supply Voltage “A” Circuit/Open". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.
When the PCM or one of the control modules that support and feed into it (e.g., the fuel control module, antilock brake control module, body control module, etc.) detects a fault in the supply voltage to the “A” circuit, the P0657 code will be stored, and the Check Engine light will be illuminated.
The PCM and the vehicles other control modules are constantly performing self-checks and self-monitoring to ensure that the PCM is functioning efficiently and properly. The PCM does this through checks of output signals, internal circuits, and checks on its internal memory status. If there’s a malfunction during this monitoring process, the PCM will store the P0657 code after a predetermined number of drive cycles. Some vehicles will require up to eight cycles of malfunctions, while others will require fewer.
The most common causes of a P0657 code include:
When a P0657 code is stored, you can expect the following symptoms:
When diagnosing a P0657 code, a mechanic will first use an OBD-II scanner to identify the code and any other codes that may be related to it. They will then perform a visual inspection of any affected circuits to look for damaged, corroded, or loose wires or connectors.
If they do not see any damage to the circuit(s), they will likely use an ohmmeter to test the circuit(s) for shorts or open connections. Once they find the cause of the problem, they’ll diagnose and fix it, and then they’ll retest the system to ensure that the code is not stored again.
When a P0657 code is stored, other codes may also be stored and symptoms may occur as a result of the breakdown in internal communication due to the open or shorted circuit. Resolving these symptoms will not solve the underlying problem, which is the open or shorted circuit. So, if other codes are found in relation to a P0657 code, you will almost always want to deal with the P0657 code first.
Though it may not have severe symptoms of its own, a P0657 code can cause other problems in the engine due to a malfunction within the PCM or one of its circuits. In addition to a rough riding engine, this can lead to a number of other potentially severe and dangerous problems. Thus, it’s important to get your P0657 code diagnosed and resolved ASAP.
Though the problem causing this code will almost always be a shorted or open circuit, there are a few different repairs that may fix it, including:
Even if your vehicle seems to be running smoothly with a stored P0657 code, if you need to get an OBD-II emissions test performed in order to renew your registration, you will need to address the problem and clear the code. If the code is stored at the time of your emissions test, it will illuminate the Check Engine light, which will make your vehicle ineligible to pass.
YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.