Actuator Supply Voltage 'A' Circuit/Open

What it means

P0657 means the engine control module cannot detect current flow in the Actuator Supply Voltage 'A' Circuit circuit: the circuit is electrically open somewhere between the module, the connector and the component.

This entry is compiled automatically from the standard definition and typical diagnostic practice for this type of fault. A detailed, reviewed article is in preparation.

Symptoms

• Check engine light on
• Engine may not start or runs in limp mode
• Several unrelated codes stored at once
• Erratic gauge or warning light behaviour

Common causes

1. Damaged, chafed or corroded wiring in the Actuator Supply Voltage 'A' Circuit circuit
2. Corroded, loose or water-damaged connector terminals
3. Failed Actuator Supply Voltage 'A' Circuit component (sensor, solenoid or actuator)
4. Poor ground connection for the module or component
5. Faulty control module driver (rare, confirm all else first)

How to diagnose

1. Read freeze frame data and note when the code set (cold start, under load, after rain)
2. Inspect the Actuator Supply Voltage 'A' Circuit connector for bent pins, corrosion and water; wiggle the harness with the engine running and watch live data
3. Measure supply voltage and ground at the connector with the key on
4. Check the signal wire for shorts to ground or battery and for continuity to the control module
5. Test or substitute the Actuator Supply Voltage 'A' Circuit only after wiring and connectors are confirmed good
6. Clear the code and complete a drive cycle to confirm the repair

Related codes

Nearby codes in this group

• P0656Fuel Level Output Circuit
• P0658Actuator Supply Voltage 'A' Circuit Low
• P0655Engine Hot Lamp Output Control Circuit
• P0659Actuator Supply Voltage 'A' Circuit High
• P0654Engine RPM Output Circuit
• P0660Intake Manifold Tuning Valve Control Circuit/Open
• P0653Sensor Reference Voltage 'B' Circuit High
• P0661Intake Manifold Tuning Valve Control Circuit Low