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P codepowertrainMedium severity

P0665Intake Manifold Tuning Valve Control Circuit High (Bank 2)

The control circuit for the Bank 2 intake manifold tuning valve is reading a higher voltage than expected, typically from a short to voltage or an open with the driver off.

Definition

The PCM drives the Bank 2 intake manifold tuning valve to alter runner geometry for optimal cylinder filling, and it monitors the control circuit voltage against expected values. P0665 sets when the circuit voltage remains above the expected threshold, which indicates a short to battery voltage, an open circuit seen through an internal pull-up, or a failed actuator. Driveability effects are mild — a flat spot in low-RPM torque or reduced high-RPM power depending on the default valve position — along with an illuminated MIL that will cause an emissions-test failure. The engine otherwise starts and runs normally.

Common causes

  • Control wire shorted to battery voltage from harness chafing
  • Open circuit in the wiring or connector between the PCM and the Bank 2 actuator
  • Failed tuning valve actuator with an open winding
  • Corroded or spread terminals at the actuator connector causing high resistance
  • Faulty PCM driver transistor (rare)

Common misdiagnoses

  • Replacing the intake manifold assembly when a single wire or connector is at fault
  • Replacing the actuator without checking for a short to voltage in the harness
  • Replacing the MAP or barometric pressure sensor
  • Blaming vacuum leaks and replacing intake gaskets for a purely electrical circuit code

Troubleshooting steps

  1. 1.Check for companion codes

    If Bank 1's P0662 is also stored, focus on a shared power feed or harness section common to both actuators.

  2. 2.Actuate the valve with a scan tool

    Use bidirectional control to command the Bank 2 tuning valve and confirm whether it responds; a dead actuator confirms a hard circuit fault.

  3. 3.Measure voltage at the actuator connector

    With the key on, verify the supply feed shows battery voltage and back-probe the control circuit; constant battery voltage on the control wire with the driver commanded on points to a short to power or open ground path.

  4. 4.Test circuit continuity to the PCM

    Key off and both connectors disconnected, verify less than 1 ohm end-to-end on the control wire and no continuity to the supply circuit.

  5. 5.Measure actuator resistance and check for binding

    An OL reading on the winding means a failed actuator; also confirm the linkage and flap move freely so a replacement is not immediately overloaded.

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