OBD-II trouble code
P0665: Intake Manifold Tuning Valve Control Circuit High (Bank 2)
The module cannot pull the Bank 2 tuning valve circuit down when it commands the valve on. The word "high" hides two opposite faults — a broken wire and a short to battery voltage — and one five-minute test tells them apart before anything is taken off the engine.
Quick facts
- System
- Powertrain
- Category
- Air Intake / Manifold Control
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $0 – $1,400
- DIY difficulty
- Advanced DIY
What does P0665 mean?
The intake manifold tuning valve switches a passage inside the manifold so the intake tract resonates usefully at more than one engine speed. The module operates the Bank 2 solenoid by grounding it, so the control wire normally sits near battery voltage at rest and drops close to zero when the valve is commanded on. P0665 sets when that drop never happens: the module asked for the valve, watched the line, and found it still sitting high.
Here is the part that matters and that the code name does not tell you. "High" is not one fault, it is two faults with opposite repairs. Either the circuit is broken somewhere between the module and the solenoid — in which case the line reads high because nothing is connected to pull it down — or something is feeding battery voltage onto it, in which case the module is pulling and being overpowered. Replacing the solenoid fixes neither of those in most cases, which is why this code has a poor reputation for repeat repairs.
The test that separates them costs nothing. Unplug both the solenoid and the module connector, then measure the control pin at the solenoid end. An open circuit reads nothing at all, because with the module removed there is no source. A short to power still reads close to battery voltage with everything disconnected, because the voltage is arriving from somewhere else entirely — a chafed loom lying against a fused feed, a corroded connector bridging two adjacent pins, or a repair splice from earlier work. Do that measurement first and the rest of the job is decided.
One population note worth knowing before spending money. On several four-cylinder direct-injection engines the equivalent device is a variable charge motion actuator with a small plastic gear train inside a sealed housing. When those gears strip or the internal motor windings fail, the circuit codes follow, and no amount of wiring work helps because the fault is inside the part. If the vehicle is one of those and the harness tests clean, the actuator genuinely is the answer.
Finally, the code-pairing read. P0665 stored on its own is a Bank 2 problem. P0665 stored next to P0662 — the same fault on the other bank — is almost never two solenoids failing on the same day. Two banks reporting the same open at once points at what they share: a common ignition feed, a fuse, or the module output stage. Check the shared item before quoting two actuators.
Common causes
- Open circuit in the Bank 2 control wire between the module and the solenoid
- Connector unlatched, backed-out terminal or broken lock at the Bank 2 solenoid
- Short to battery voltage from a chafed loom resting against a fused feed
- Tuning valve solenoid with an open internal winding
- Variable charge motion actuator with a stripped internal gear train or failed motor
- Corrosion bridging adjacent pins in a firewall-side connector
- Blown fuse or lost ignition feed shared with other solenoids
- Failed module output driver stuck in the off state
- Damaged repair splice from previous rear-bank work
Symptoms
- Check engine light with P0665 stored
- The Bank 2 tuning valve never actuating when commanded with a scan tool
- A flat spot at one end of the rev range while the other end feels normal
- Reduced fuel economy, typically in the region of five to fifteen percent
- Hesitation on acceleration as the engine leaves the tuned part of the range
- Circuit codes from unrelated solenoids appearing at the same time when a shared feed is lost
- No symptom at all on some vehicles beyond the stored code
Diagnostic steps
- 1.Command the Bank 2 valve on and off with a scan tool and watch the circuit state. A line that never changes confirms the module's report rather than an intermittent.
- 2.Unplug both the solenoid and the module connector, then measure the control pin at the solenoid. Voltage still present with everything disconnected means a short to power; nothing present means an open.
- 3.If the reading says open, check continuity of that one wire end to end rather than testing the solenoid, because the solenoid is not in the circuit the module is complaining about.
- 4.Inspect the connector for a backed-out terminal or an unlatched lock. On a bank that has been disturbed for service work, this is quicker to check than to rule out later.
- 5.Measure the Bank 2 solenoid coil resistance and compare it with the Bank 1 solenoid on the same engine. An open winding shows immediately against a known-good twin.
- 6.Confirm which physical side of the engine is Bank 2 on this vehicle before removing anything, since bank numbering follows cylinder numbering and not position.
- 7.If P0662 is stored alongside this code, stop testing individual solenoids and check what the two circuits share — fuse, ignition feed, ground or module.
- 8.On engines that use a sealed variable charge motion actuator, test the harness first and only then condemn the actuator, since its failure mode is internal and unrepairable.
- 9.Repair the fault, clear the code, then command the valve again and confirm the circuit now switches under load rather than trusting a cleared light.
Repair cost
$0 – $1,400
An unlatched connector costs nothing to fix and is found often enough on a bank that has recently been apart to be worth the two minutes. Diagnosis is $100 to $200. Repairing an open or shorted control wire runs $180 to $700, the top of that band applying where the damage is behind a transverse engine and the loom has to be opened with poor access. Replacing the Bank 2 solenoid is $150 to $400 with direct access and $450 to $1,000 where ducting, cowl or plenum removal comes first. A sealed variable charge motion actuator is typically $200 to $600 fitted. If the module output stage has failed, replacement and programming is $700 to $1,400.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with intake manifold runner control actuator replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an advanced DIY job. It typically requires specialty tools, scan-tool access, lifting equipment, or careful sequencing to avoid causing new failures. Plan for extended downtime and have a backup vehicle. Most owners are better served by a shop that has done this repair before.