19-12-2021
11 min.
5702

P0660 Intake Manifold Tuning Valve Control Circuit/Open (Bank 1)

The P0660 � Intake Manifold Tuning Valve Control Circuit/Open (Bank 1) diagnostic trouble code (DTC) indicates that the Engine Control Module (ECM/PCM) has detected an open or interrupted electrical circuit in the control system for the Intake Manifold Tuning Valve on Bank 1.

The intake manifold tuning system changes the path through which air enters the engine according to engine speed and load. This system can help improve low-RPM torque, high-RPM power, throttle response, fuel economy, and emissions.

The key word in P0660 is "Open." This generally means that the electrical circuit between the control module and the intake manifold tuning actuator is interrupted or does not have the expected electrical continuity.

What Does P0660 Mean?

In simple terms:

The ECM has detected an open electrical circuit in the Intake Manifold Tuning Valve control system for Bank 1.

The basic system can be thought of as:

ECM/PCM → Wiring → Intake Manifold Tuning Actuator → Runner Mechanism

Depending on the vehicle, the system may use:

An electric actuator
An electric motor
A control solenoid
A vacuum actuator controlled by a solenoid
An actuator with an integrated position sensor

The exact arrangement varies between manufacturers.

What Is an Intake Manifold Tuning Valve?

The Intake Manifold Tuning Valve (IMTV) controls airflow through different passages in the intake manifold.

The engine needs different airflow characteristics at different RPMs.

At lower engine speeds, the system may use a longer intake path to improve torque.

At higher RPM, it may change the airflow path to improve cylinder filling and power.

The system therefore helps the engine achieve better performance across a wider operating range.

What Does "Bank 1" Mean?

Bank 1 is the cylinder bank that contains cylinder number 1.

Bank terminology is mainly used on engines with multiple cylinder banks, such as:

An inline engine normally has only one cylinder bank.

Always verify Bank 1 using the manufacturer's service information because the physical location of the actuator varies between engine designs.

What Does "Circuit/Open" Mean?

"Open" means that the expected electrical path is interrupted.

For an actuator to operate correctly, the electrical circuit must have a complete path.

An open circuit can be caused by:

Broken wire
Disconnected connector
Loose terminal
Corroded terminal
Failed actuator winding
Blown fuse
Missing power supply
Poor ground
Damaged connector
Broken wiring inside the insulation

The result is that the ECM cannot properly control the intake manifold tuning system.

What Causes P0660?

Possible causes include:

Faulty intake manifold tuning valve actuator
Failed intake manifold runner control motor
Faulty control solenoid
Broken wiring
Open control circuit
Disconnected connector
Corroded connector
Loose electrical terminal
Blown fuse
Missing power supply
Poor ground
Damaged wiring harness
Water intrusion
Faulty position sensor
ECM/PCM control circuit failure

Mechanical problems such as a stuck runner can also occur, although a purely mechanical fault does not itself create an electrical open circuit.

Can a Bad Intake Manifold Tuning Valve Cause P0660?

Yes.

If the actuator's internal electrical circuit is open, the ECM can detect an interruption.

For example, an actuator motor or solenoid winding may fail internally while the external wiring remains intact.

This is why actuator resistance and operation should be checked before replacing the entire intake manifold.

Can a Broken Wire Cause P0660?

Yes.

A broken wire is one of the most common possibilities for an open-circuit code.

Pay particular attention to wiring located:

Near the engine
Near exhaust components
Around moving parts
Near sharp brackets
In areas exposed to oil
In areas exposed to water

Engine vibration can also cause a wire to break internally while the outer insulation still appears intact.

Can a Bad Connector Cause P0660?

Yes.

A disconnected or poorly connected actuator connector can immediately create an open circuit.

Inspect for:

Disconnected plugs
Corrosion
Bent pins
Loose terminals
Damaged locking tabs
Water intrusion
Poor terminal tension

A connector can look normal externally but still have poor electrical contact.

Can a Blown Fuse Cause P0660?

Yes, depending on the vehicle.

Some intake manifold tuning systems receive actuator power through a fuse.

If the fuse is blown, the actuator may lose its power supply and the ECM may detect an open or inactive circuit.

However, replacing the fuse alone is not enough.

If the fuse has failed, determine why it failed before returning the vehicle to normal operation.

Can a Poor Ground Cause P0660?

Yes, depending on the circuit design.

Some systems require a dedicated actuator ground or an ECM-controlled ground.

A poor ground can prevent the actuator from operating and cause the control system to interpret the circuit as open.

Check:

Actuator ground
ECM ground
Engine ground straps
Chassis grounds

A voltage-drop test can be more useful than simply checking continuity.

Can Carbon Buildup Cause P0660?

Usually not directly.

Carbon deposits can make the intake runner mechanism difficult to move.

The runner can become:

Sticky
Restricted
Slow
Stuck

However, carbon buildup normally does not create an electrical open circuit.

For P0660, the electrical circuit should therefore be checked first.

Can a Vacuum Leak Cause P0660?

Normally not directly.

Some intake manifold tuning systems use a vacuum actuator controlled by an electrical solenoid.

A vacuum problem can prevent the runner from moving, but a simple vacuum leak generally does not create an electrical open circuit.

On a vacuum-operated system, inspect both:

Electrical circuit → Vacuum system → Actuator → Mechanical runner

Symptoms of P0660

Possible symptoms include:

Check Engine Light
Reduced engine performance
Poor acceleration
Reduced low-RPM torque
Reduced high-RPM performance
Hesitation
Poor throttle response
Increased fuel consumption
Increased emissions

Some vehicles may have no obvious drivability symptoms other than the Check Engine Light.

Can P0660 Cause Reduced Power?

Yes.

If the intake tuning valve cannot change the airflow path correctly, the engine may not receive the airflow characteristics expected at a particular RPM and load.

This can result in:

Reduced torque
Slower acceleration
Hesitation
Poor high-RPM performance

Some vehicles may also activate reduced-power or fail-safe operation.

Can P0660 Cause Poor Fuel Economy?

It can.

The intake tuning system helps optimize airflow and combustion efficiency.

If the system is disabled or stuck in the wrong position, the engine may operate less efficiently under certain conditions.

The effect depends on the engine design and the position in which the valve remains.

Can P0660 Cause Rough Idle?

Sometimes, but it is not a defining symptom.

An incorrectly positioned intake tuning valve can affect airflow characteristics.

However, rough idle has many other possible causes, including:

Vacuum leaks
Throttle body problems
MAF sensor problems
MAP sensor problems
Fuel-system faults
Ignition problems

These should be diagnosed separately.

Can P0660 Cause a No-Start Condition?

Normally, no.

An intake manifold tuning valve circuit fault generally does not prevent an otherwise healthy engine from starting.

If a vehicle with P0660 has a no-start condition, other systems should be investigated.

Can P0660 Damage the Engine?

Usually, P0660 does not directly cause immediate mechanical engine damage.

The engine will normally continue to operate even if the intake tuning system is unavailable.

The primary consequences are generally:

Reduced performance
Increased fuel consumption
Increased emissions

However, if the runner mechanism has physically broken and components can enter the intake or engine, the situation can become more serious.

How Is P0660 Diagnosed?

A systematic diagnostic approach is recommended.

1. Scan for all DTCs

Look for additional codes involving:

Intake manifold tuning
Runner position
MAF
MAP
Throttle
Vacuum
Engine performance

Related codes can help identify the actual cause.

2. Confirm Bank 1

Identify the cylinder bank containing cylinder 1.

3. Locate the tuning actuator

Determine whether the system uses:

Electric motor
Solenoid
Vacuum actuator
Integrated position sensor

4. Inspect the connector

Check for:

Disconnection
Corrosion
Bent pins
Loose terminals
Water intrusion

5. Inspect the wiring

Look for:

Broken wires
Open circuits
Chafing
Melted insulation
Incorrect previous repairs

6. Check fuses

Verify that any relevant fuse is intact.

If a fuse is blown, investigate the cause before replacing it.

7. Check power and ground

Confirm that the actuator receives the required supply voltage and ground.

8. Test circuit continuity

With the circuit isolated according to the manufacturer's procedure, check continuity between the appropriate terminals.

9. Test the actuator

Measure resistance where specified and test actuator operation according to manufacturer instructions.

10. Check mechanical movement

Verify that the intake runner mechanism moves freely.

11. Check position feedback

If the actuator has a position sensor, compare commanded and actual positions.

Can a Multimeter Diagnose P0660?

Yes.

A multimeter can help identify many open-circuit problems.

It can be used to check:

Power supply
Ground
Wiring continuity
Control circuit continuity
Actuator resistance
Short circuits

However, the correct resistance and voltage specifications are vehicle-specific.

A resistance measurement alone does not prove that an electronically controlled actuator is functioning correctly.

Can a Scan Tool Diagnose P0660?

Yes.

An advanced scan tool can provide additional information.

Depending on the vehicle, it may allow you to:

Command the intake tuning actuator
Monitor actuator status
View commanded position
View actual position
Monitor position feedback
Read freeze-frame data

A basic OBD scanner may only show the P0660 code.

Can an Oscilloscope Help Diagnose P0660?

Yes.

An oscilloscope can be helpful when the actuator uses:

PWM control
Variable control signals
Electronic motor control
Position feedback

It can reveal intermittent or abnormal control signals that may be difficult to identify with a multimeter.

Can P0660 Be Caused by the ECM?

Yes, but ECM failure should generally be considered after external causes have been eliminated.

The ECM controls the intake manifold tuning system.

An internal ECM driver fault could potentially cause an abnormal or missing control signal.

Before replacing the ECM, verify:

Actuator
Wiring
Connector
Power supply
Ground
Position feedback
Mechanical operation

What If P0660 Returns Immediately After Clearing?

If P0660 returns immediately, a persistent electrical fault is likely present.

Focus on:

Disconnected actuator
Broken wire
Open circuit
Failed actuator
Missing power supply
Poor ground
Corroded connector
ECM control circuit

If the code only returns during certain driving conditions, investigate intermittent wiring and mechanical operation.

What If P0660 Is Intermittent?

An intermittent open circuit can be difficult to locate.

Possible causes include:

Loose connector
Corroded terminal
Broken wire inside insulation
Harness movement
Engine vibration
Heat-related wiring problems
Intermittent actuator failure

A careful harness inspection while monitoring the circuit can help identify the fault.

Is P0660 a Serious Code?

Usually, P0660 is a moderate-severity fault.

The vehicle will often remain drivable.

However, ignoring the problem can lead to:

Reduced performance
Poor acceleration
Increased fuel consumption
Increased emissions
Reduced-power operation on some vehicles

If severe power loss occurs, the vehicle should be diagnosed promptly.

Can You Drive With P0660?

Usually, short-term driving is possible if the engine operates normally.

However, the fault should be diagnosed rather than ignored.

Avoid unnecessary driving if you experience:

Severe power loss
Significant hesitation
Limp mode
Rough engine operation
Flashing Check Engine Light

How Is P0660 Repaired?

The repair depends on the confirmed cause.

Possible repairs include:

Repairing broken wiring
Repairing an open circuit
Replacing damaged terminals
Repairing or replacing the connector
Replacing a blown fuse after finding its cause
Repairing the power supply
Repairing the ground circuit
Replacing the intake manifold tuning actuator
Replacing the control solenoid
Repairing vacuum lines on applicable systems
Repairing the runner linkage
Cleaning carbon deposits where appropriate
Replacing the intake manifold assembly if mechanically damaged
Repairing or replacing the ECM in rare cases

Does P0660 Mean the Intake Manifold Must Be Replaced?

No.

P0660 does not automatically indicate that the complete intake manifold is defective.

The problem may be a simple:

Broken wire
Disconnected connector
Corroded terminal
Blown fuse
Failed actuator
Poor ground

The intake manifold should only be replaced if inspection confirms internal mechanical damage or if the tuning mechanism cannot be serviced separately.

P0660 vs. P0661 and P0662

These codes describe different electrical conditions in the intake manifold tuning system:

P0660 – Intake Manifold Tuning Valve Control Circuit/Open (Bank 1)

The control circuit appears to be open or interrupted.

P0661 – Intake Manifold Tuning Valve Control Circuit Low (Bank 1)

The control circuit signal is below the expected electrical range.

P0662 – Intake Manifold Tuning Valve Control Circuit High (Bank 1)

The control circuit signal is above the expected electrical range.

This distinction is important because an open-circuit code should lead the diagnosis toward wiring, connectors, power supply, ground, and actuator continuity before focusing on mechanical intake problems.

Common Diagnostic Mistakes

Assuming the entire intake manifold is defective

The actuator or wiring may be the actual cause.

Cleaning the intake without testing the electrical circuit

Carbon buildup can cause mechanical problems, but P0660 specifically identifies an open circuit.

Replacing the actuator without checking the wiring

A broken wire can produce the same DTC even when the actuator is good.

Ignoring the fuse

A blown fuse can interrupt actuator power on some systems.

Ignoring Bank 1

The correct cylinder bank must be identified before testing components.

Replacing the ECM too quickly

ECM failure is possible but generally less common than wiring, connector, actuator, or power-supply problems.

How Do You Clear P0660?

The proper diagnostic sequence is:

Scan all modules → Record all DTCs → Check freeze-frame data → Identify Bank 1 → Inspect actuator and connector → Check fuses → Check power and ground → Test circuit continuity → Test actuator → Inspect runner movement → Check position feedback → Repair the confirmed fault → Clear the DTC → Test-drive → Rescan

If P0660 returns, the underlying open-circuit problem has not been corrected.

Final Thoughts on P0660

P0660 – Intake Manifold Tuning Valve Control Circuit/Open (Bank 1) indicates that the ECM has detected an open or interrupted electrical circuit in the intake manifold tuning valve control system for Bank 1.

The most important areas to investigate are:

Actuator → Connector → Wiring → Fuse → Power → Ground → Control circuit → Runner mechanism → Position feedback → ECM

Possible causes include a broken wire, disconnected or corroded connector, failed actuator, blown fuse, poor ground, open control circuit, mechanical runner problem, or ECM failure.

The important point is that P0660 does not automatically mean the intake manifold needs to be replaced.

Because this is specifically an open-circuit code, electrical testing should normally come before replacing expensive intake components.