P0657 - ACTUATOR SUPPLY VOLTAGE "A" CIRCUIT/OPEN

The Engine Control Module (ECM) monitors and regulates the operation of the engine’s actuators, sensors, and other components to achieve the most efficient performance from the engine.

When the P0657 OBD2 diagnostic code is set and the other related codes indicate that the ECM has encountered a malfunction in the actuator, and this condition is due to an open circuit. It should be noted that by designating it as A, the manufacturer may be referring to a particular circuit, wiring, or area, so it is necessary to consult the vehicle’s information source.

• Check Engine light is ON.
• A meaningful increase in fuel consumption.
• Difficulties in engine revolutions.
• Limited engine power.

The P0657 OBDII fault code is set by one or more of the following reasons:

• The Engine Control Module input sensor circuits may have faulty wiring or connectors.
• The control module connectors may be damaged by water clogging.
• The charging system may be unstable.

Steps to solve the P0657 OBD2 DTC:

• As a first step, consult the TSB (Technical Service Bulletins).
• Inspect the circuit components that are related to the actuator. Look for damage due to burns or corrosion. If such deficiencies are discovered, make any necessary repairs or replacements.
• Verify the actuator is in good condition. Take readings of the actuator voltages and compare these results with those given in the service manual. If inconsistencies are discovered, make corrections if necessary.