P0657 OBD-II Trouble Code: Actuator Supply Voltage “A” Circuit/Open

Our certified mechanics come to you · Get a fair and transparent estimate upfront

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0657 code

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.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$20.00
Toyota$20.00
BMW$20.00
SCHEDULE P0657 DIAGNOSTIC Get a fair and transparent estimate upfront

P0657 code definition

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.

What the P0657 code means

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.

What causes the P0657 code?

The most common causes of a P0657 code include:

  • An open or shorted circuit in the PCM
  • An open or shorted circuit between two interfacing supporting control modules
  • An open or shorted circuit between the engine sensors and the PCM
  • A disconnected ground wire running to a control module
  • An internal malfunction within the PCM

What are the symptoms of the P0657 code?

When a P0657 code is stored, you can expect the following symptoms:

  • The Check Engine light will illuminate.
  • The engine may be difficult to start or may not start at all.
  • The engine may run rough at idle or while driving at speed.
  • The engine may misfire and/or have a lack of power, especially when accelerating.

How does a mechanic diagnose the P0657 code?

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.

Common mistakes when diagnosing the P0657 code

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.

How serious is the P0657 code?

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.

What repairs can fix the P0657 code?

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:

  • Securing and tightening PCM connectors and/or ground wires.
  • Repairing or replacing the PCM wiring harness.
  • Reprogramming the PCM.
  • Replacing the PCM.

Additional comments for consideration regarding the P0657 code

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.

Need help with a P0657 code?

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.

trouble codes
P0657
Check Engine Light

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P0657 code.

SCHEDULE P0657 DIAGNOSTIC
Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating

(6,144)

Rating Summary
5,685
221
51
35
152
5,685
221
51
35
152

Chris

11 years of experience
13 reviews
Chris
11 years of experience
Ford F-150 - Check Engine Light is on - North Salt Lake, Utah
We were having problems with our check engine light, and Chris was exceptionally thorough until he found the problem and could help resolve the situation. We appreciate having someone who cares enough to get the job done right, not just done. We will definitely use Chris' services in the future. Thanks Chris.

Leng

21 years of experience
2 reviews
Leng
21 years of experience
Mazda MPV - Check Engine Light is on - Seattle, Washington
Leng arrived on time and explained the issue that my van is having. I will make a follow up appointment for the fix. Friendly, easy to talk to, and professional - thank you very much!

Okela

13 years of experience
11 reviews
Okela
13 years of experience
Land Rover LR4 - Check Engine Light is on - Brooklyn, New York
Okela was incredible! He is super thorough and took time to walk us through the issues with our LR4. Couldn’t recommend more! Thank you Okela!!

Robert

37 years of experience
188 reviews
Robert
37 years of experience
Land Rover LR2 - Check Engine Light is on - Atlanta, Georgia
Robert arrived on time. Did a diagnostic check quickly. He was friendly, and gave great service. He knows how to work on a Land Rover.


More related articles

Related questions

Engine light came on! Upper radiator hose blue!

Hello. The Check Engine Light will need to have a scanner connected to it and retrieve any stored codes that may have been caused by the overheating when the hose blew out. Once the codes are retrieved then the codes...

Is a high RPM maintained all-throughout a ride normal?

Hello. The first thing you should do now that a warning light has illuminated is to have the vehicle scanned for diagnostic troubleshooting codes. These codes will tell you what system (air, fuel, or spark) the computer is having problems...

Engine replaced, check engine light on again

Hello. There are several reasons why the Check Engine Light is on, but the Check Engine Light is not always an indication that the motor will need to be replaced. A Check Engine Light that is steady may indicate a...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com