P0660 code definition
The P0660 code indicates a problem with engine bank 1’s intake manifold tuning valve control circuit.
What the P0660 code means
If there is an error in the intake manifold tuning valve circuit, this trouble code is stored. The problem could have been detected by the PCM, or by another module, including (but not necessarily limited to):
- The transmission control module
- The anti-lock brake control module
- The body control module
- The turbo control module
- The traction control module
- The instrument panel control module
- The anti-theft module
- The proximity alert module
- The cruise control module
- The climate control module
What causes the P0660 code?
Three are hardly ever problems with the vehicle’s PCM itself, but the P0660 is the exception that proves the rule. The problem could be a poor electrical connection or a defective driver in the PCM. Other causes could be:
- Damaged wiring or connectors in the CAN bus harness
- Broken ground wire
- Loose control module
- Faulty fuel injector control module The CAN bus itself could also be defective.
What are the symptoms of the P0660 code?
The Check Engine Light will probably come on. If it doesn’t, then the code may have been stored as pending. Other symptoms include:
How does a mechanic diagnose the P0660 code?
This type of problem is often related to issues with the CAN (controller area network bus), which is what enables communication between multiple microcontrollers in the vehicle, in order to regulate most of the electrical functions. The PCM serves as the master controller. Sometimes (but not often) individual controllers will fail, so the mechanic will check each module, and replace any that are defective. The process can include the following measures (but not necessarily all of them):
A visual examination of wiring and connectors
Replacement of any damaged components
A re-test of the system
Recording the codes and freeze frame data, then clearing them out and operating the vehicle to see if they re-appear
If the codes are intermittent, allowing the problem to worsen in order to arrive at a correct diagnosis
Using special scanners (Autohex or Tech II) to locate the general area where the issue is happening
Disconnecting and testing every CAN bus pin (this could be very time-consuming, and should be avoided if possible)
Checking the control module ground circuits using battery ground
Using auxiliary ground cable to find ground discrepancies
Looking for any loose or corroded connectors that could be leading to increased circuit resistance
Checking each individual controller connector for continuity, using a digital volt ohmmeter and a CAN bus wiring diagram, possibly along with a pin out value chart
Comparing the results with the approved specifications provided by the vehicle manufacturer, and fixing any open or shorted circuits
If the problem is not corrected, replacing the PCM
Common mistakes when diagnosing the P0660 code
Practically any code that is stored in response to an engine misfire, fuel injector issue or lean exhaust can be easily misdiagnosed, and if the wrong components are replaced, the repair will not be successful. When mechanics do not diagnose P codes in the order they are stored, the result can be an unsuccessful diagnosis.
How serious is the P0660 code?
If accompanied by engine stalling, the P0660 code is serious. This is a safety issue, and could endanger you, your passengers, or other motorists and passengers. Even if the only issue seems to be bad fuel economy, the situation could worsen, so you should get this fixed at your earliest convenience.
What repairs can fix the P0660 code?
Bad wiring, connectors, and modules can be repaired or replaced. The CAN bus can also be replaced, and if the PCM itself is at fault, it can be replaced.
Additional comments for consideration regarding the P0660 code
Due to the complexity of the wiring harnesses, it is often more economical to replace them rather than devotion a lot of time to repairing the wiring.
Need help with a P0660 code?
You can always count on YourMechanic. We will provide you with a free quote, and then send a qualified mobile mechanic to the location of your choice to repair your vehicle. You can reach us at 1-800-701-6230, or book an appointment using our online form.