OBD-II Code P0660 — What It Means & How to Fix It

What Does This Error Mean?

P0660 means there is a problem with the intake manifold tuning valve control circuit on Bank 1. The intake manifold tuning valve (also called a variable intake manifold valve) adjusts the length of the intake runners. Short runners help at high RPM, long runners help at low RPM for better torque. When the solenoid that controls this valve fails, P0660 is set. You may notice reduced power at certain RPM ranges or slightly poor fuel economy.

Affected Models

All vehicles 1996+ with variable intake manifold systems
Common in Ford Mustang and F-150 with certain engines
Common in Honda V6 engines
Common in Nissan V6 engines
Common in GM V6 and V8 engines with Active Fuel Management

Common Causes

Faulty intake manifold tuning valve solenoid that has failed electrically
Sticking or seized intake manifold tuning valve that cannot physically move
Damaged or corroded wiring to the solenoid
Blown fuse for the solenoid control circuit
Corroded solenoid connector reducing signal voltage to the solenoid

How to Fix It

Locate the intake manifold tuning valve solenoid. On most engines, it is mounted on the intake manifold and is identifiable by its electrical connector and connection to a port in the manifold.

Your repair manual will show the exact location for your engine. Some engines have two banks with separate solenoids.
Inspect the solenoid connector for corrosion, bent pins, or looseness. Clean it with electrical contact cleaner and reseat it firmly.

A poor electrical connection at the solenoid is a very common cause of this code.
Test the solenoid with a multimeter. Measure resistance across the solenoid terminals. Most solenoids should read between 10 and 40 ohms. An open (infinite resistance) or shorted (near zero) reading means the solenoid has failed.

Check your repair manual for the correct resistance specification for your specific solenoid.
Apply 12V directly to the solenoid terminals (briefly) to test if it clicks and activates. If you hear or feel a click, the solenoid mechanism works. No click means the solenoid or valve is stuck.

This test confirms mechanical operation separate from the electrical reading.
Replace the solenoid if it has failed electrically or mechanically. Clear the code and test drive across the full RPM range to verify normal engine response.

If the valve plate inside the manifold is stuck from carbon buildup, cleaning with intake manifold cleaner may free it.

When to Call a Professional

Intake manifold tuning valve solenoids are moderately priced parts. Solenoids cost $30 to $100 depending on the vehicle. Labor at a shop is $75 to $200 since access varies by engine design. If the valve itself is seized and the manifold must come off, repairs can reach $300 to $600. Total DIY repair is often under $100 if the solenoid is the only problem.

Frequently Asked Questions

Will P0660 cause my car to fail emissions testing?

Yes, in most states. Any active check engine light will cause an automatic emissions test failure. Fix P0660 and clear the code before going for an emissions test.

What does a variable intake manifold actually do?

It changes the effective length of the air passages going into the cylinders. At low RPM, longer passages help the engine make more torque — useful for towing and low-speed acceleration. At high RPM, shorter passages help the engine breathe better and make more power. A stuck valve locks you into one setting and you lose performance in the other range.

Is P0660 the same on all engines?

The code definition is the same — intake manifold tuning valve control circuit Bank 1. But the valve design and repair procedure differ between manufacturers. Always look up your specific engine to confirm the solenoid location and testing procedure.