Fix P0660: Mechanic’s solutions that WORKED

The code P0660: Intake Manifold Tuning Valve Control Circuit/Open indicates an issue with the circuit of the intake manifold tuning valve, which plays a crucial role in managing the engine’s air intake for optimal performance. This malfunction can lead to reduced engine efficiency and power.

P0660 quick overview

Meaning	P0660: Intake Manifold Tuning Valve Control Circuit/Open
Is it serious?	This code can be serious as it may affect the engine’s performance, particularly in terms of power and fuel efficiency.
Possible causes	– Faulty intake manifold tuning valve – Damaged wiring or poor connections in the valve circuit – PCM software needs an update – Potential PCM hardware failure
How to diagnose?	Perform Diagnostic Scans: Use a scanner to confirm the P0660 code and check for any related codes. Inspect Intake Manifold Tuning Valve: Check the valve for any physical damage or malfunction. Check Wiring and Connectors: Examine wiring and connectors for damage, corrosion, or loose connections. Update PCM Software: If available, update the PCM software to the latest version. Consider PCM Replacement: If other steps fail, evaluate the need for PCM replacement. Test Power Supply During Reprogramming: Ensure a stable power supply if reprogramming is attempted.

How to fix P0660 – learn from mechanics

I looked into P0660 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Dodge

Vehicle Information: 2010 Dodge Journey SXT 3.5L MIL Lamp on

Issue + Repair History:

• Check engine light on with code PO660 for Manifold Tuning Valve (MTV) Control Circuit.
• MTV did not move when activated with scanner.
• Tested wiring and connectors to PCM and MTV.
• Jumped power to control wire at PCM connector, and MTV functioned.
• Found 5-volt reference and sensor ground at MTV.
• Voltage readings on signal wire out of MTV were inconsistent.

Suggestions to Fix Issue:

• Verify if the PCM can command action of the MTV.
• Consider the possibility of a bad MTV due to faulty position sensor.
• Check emissions warranty coverage as the issue might be common.
• Analyze supply current to MTV for non-linear load indicating a faulty MTV.

Final Fix:

• Confirmed that the Manifold Tuning Valve was bad.
• Awaiting customer decision for repair authorization.

Case #2: Chrysler

Vehicle Information: 2006 Chrysler Pacifica Touring 3.5L MIL Lamp on

Issue + Repair History:

• Intermittent shift lock, no power to accessories.
• Vehicle started but couldn’t shift out of park; no power windows, radio, or accessories.
• Problems occurred on a hot day, but vehicle functioned normally after sitting overnight.
• DTC codes present but deemed unrelated to the main issue.
• Suspected issue with the power module.

Suggestions to Fix Issue:

• Perform a complete module scan, especially TPIM modules.
• Check grounds on the left frame rail/inner fender under the battery tray.
• Examine the TIPM, including battery condition and wiring/grounds near the battery.

Final Fix:

• Found corroded and loose grounds under the battery/fender wall.
• Ground eyelet with six wires was specifically affected.
• Conducted a wiggle test and split the six wires into two terminals with weather crimp.
• Also discovered two shaved wires from the harness rubbing on transmission cooler lines.

Case #3: Ford

Vehicle Information: 2004 Ford F-150 XLT 4.6L MIL Lamp on

Issue + Repair History:

• Truck is a salvage title, possibly involved in a major accident or rollover.
• Computer displaying codes P0660, P1703, and P2106.
• ABS light showing a code related to the intake manifold tuning valve, but the valve or harness not visible.
• Suspected a bad computer due to irrelevant codes.
• Previously came in with check engine light for fuel pump module and P0660 code.

Suggestions to Fix Issue:

• Check if the intake manifold tuning valve is located at the back of the engine.
• Verify if the computer is the correct one for the specific truck model and engine.
• Reset codes and check if they return.
• Inspect throttle by wire system and consider PCM replacement if necessary.
• Check for leaking rectifier diodes in the alternator and conduct a wiggle test on the wiring harness.

Final Fix:

• After removing the intake and finding no valve present, replaced the computer which was giving false codes.
• The truck worked fine after replacing the computer.

Case #4: Chrysler

Vehicle Information: 2005 Chrysler 300 Limited 3.5L Poor Idle Quality, Hesitation, Surge

Issue + Repair History:

• Vehicle exhibited rough idle, surging, and poor throttle response.
• Replaced gas pedal and sensor due to initial code for gas pedal sensor.
• Despite replacement, vehicle still had issues with throttle response, only reaching about 1500rpm.
• BAS and ESP lights were on, with most codes related to throttle control.

Suggestions to Fix Issue:

• Check for vacuum leaks, especially around the EGR valve and intake pipe.
• Perform a relearn procedure after changing the pedal sensor.
• Clear codes and retest to check if they return.
• Consider potential intake leak or intake plenum replacement.
• Relearn gas pedal with a Chrysler enhanced scanner.
• Assess the need for PCM reflash and check for wiring problems, focusing on sensor voltage and PCM grounds.

Final Fix:

• Discovered that an O-ring had come out of the intake and damaged the mass air flow sensor.
• After repairing these issues, the vehicle still required PCM relearn and flash at a Chrysler dealership.
• The vehicle ran well after these repairs and updates.

Case #5: Mazda

Vehicle Information: 2004 Mazda MPV ES 3.0L PCM Blank

Issue + Repair History:

• Came in for SES lamp P0660 and attempted update with new program.
• PCM blanked out during programming and now will not reflash.
• Multiple attempts to reprogram (about 20 times) unsuccessful.
• Followed Mazda bulletin procedures using both tear tag number and PCM number.
• Used a charger during reprogramming due to power requirements.

Suggestions to Fix Issue:

• Avoid using a regular battery charger as voltage inconsistencies can affect reprogramming; use a jumper pack or another fully charged battery instead.
• Consider uninstalling the MDS and backdating the software as per motorcraftser troubleshooting page.
• Be aware that losing battery voltage or dropout during programming might require a new PCM with pre-set programming.

Final Fix:

• The PCM was non-recoverable and had to be replaced.
• New PCM came preprogrammed, but the pass lock module also needed replacement.
• Required two good chipped keys for programming the pass lock system to the new PCM.

Advice	Brief Description of Diagnostic Step
Check for Updates and Reprogram PCM	Verify if there is an updated program for the code and attempt reprogramming.
Inspect Wiring and Connectors	Examine the wiring and connectors related to the affected circuit for damages.
Perform Diagnostic Scans	Use diagnostic tools to scan for related codes and assess overall vehicle health.
Consider PCM Replacement	If reprogramming fails or PCM is unresponsive, consider replacing the PCM.
Check Power Supply During Reprogramming	Ensure stable power supply during reprogramming to avoid issues.
Inspect and Test Manifold Tuning Valve	Verify the functionality of the manifold tuning valve and its connections.
Review Vehicle History and Repair Background	Assess previous repairs and vehicle history for potential related issues.