Quick Answer
P0668 means: P0668 indicates a malfunction in the intake manifold tuning valve control circuit.
Can I drive with P0668? While it is safe to drive for a short distance, it's recommended to seek professional help as soon as possible.
Common Questions
What does P0668 mean and how does it affect my car?
The P0668 code signals a problem with your intake manifold tuning valve. This valve optimizes airflow in your engine, improving performance. If malfunctioning, you may notice reduced power and efficiency, and it could lead to more significant engine issues if not addressed.
What are the most common causes of P0668 and how much does it cost to fix?
Common causes include a faulty intake manifold tuning valve, damaged wiring, or a malfunctioning ECM. Repair costs can vary, but expect between $150 to $300 for valve replacement and $50 to $150 for wiring repairs.
Can I drive my car with P0668 or should I stop immediately?
While you can drive short distances with this code, it's advisable to seek repairs promptly. Continued driving could lead to further engine damage and performance issues.
How can I diagnose P0668 myself using GeekOBD APP?
Using the GeekOBD APP, conduct a full OBD2 scan to retrieve the P0668 code and any related codes. Review freeze frame data for conditions when the code triggered, and perform component tests to identify the faulty part.
What vehicles are most commonly affected by P0668?
Commonly affected vehicles include the 2015-2018 Honda Civic, 2011-2015 Ford F-150, and 2014-2019 Chevrolet Silverado. Be sure to check for any recalls or technical service bulletins (TSBs) that may apply.
How can I prevent P0668 from happening again?
Regular maintenance is key. Ensure frequent inspections of the intake system, check for vacuum leaks, and keep an eye on wiring conditions to prevent damage over time.
What is P0668?
The Diagnostic Trouble Code (DTC) P0668 indicates a problem with the intake manifold tuning valve control circuit performance or range. This code is often triggered when the engine control module (ECM) detects that the signal from the intake manifold tuning valve is outside the expected range. The intake manifold tuning valve plays a crucial role in optimizing the engine's airflow and performance, particularly at varying RPMs. Vehicles commonly affected include models from Honda (such as the 2015-2018 Honda Civic), Ford (2011-2015 Ford F-150), and Chevrolet (2014-2019 Chevrolet Silverado). When this code appears, it can lead to several issues, such as reduced engine efficiency, poor acceleration, or even engine misfires. Ignoring this code could result in further damage to the engine and decreased vehicle performance. Therefore, it is vital for car owners to address this issue promptly to maintain optimal vehicle operation and safety.
System: P - Powertrain (Engine, Transmission, Emissions)
Symptoms
Common symptoms when P0668 is present:
- Check engine light stays on constantly, indicating an underlying issue that needs attention.
- Engine hesitates during acceleration, which can create an unsafe driving experience and decrease fuel efficiency.
- Fuel economy decreased by 10-15%, leading to more frequent trips to the gas station and increased costs.
- Rough idling when the engine is at a standstill, which can cause vibrations and discomfort.
- Unusual engine noises such as knocking or pinging, indicating potential damage if not addressed.
Possible Causes
Most common causes of P0668 (ordered by frequency):
- Faulty intake manifold tuning valve (70% likelihood) - The valve may be stuck, leading to improper airflow.
- Wiring issues (15% likelihood) - Damaged or corroded wiring connections can disrupt signals to the ECM.
- Faulty engine control module (10% likelihood) - In rare cases, the ECM itself may malfunction and send incorrect signals.
- Vacuum leaks (3% likelihood) - Leaks can lead to performance issues, resulting in the code being triggered.
- Defective sensors (2% likelihood) - Sensors providing feedback to the ECM may fail, causing performance issues.
P0668 Repair Costs
Cost Breakdown by Repair Type
Intake Manifold Tuning Valve Replacement
Replacing the faulty intake manifold tuning valve to restore proper function.
- Total: $150 - $300
- Success rate: 95%
Wiring Repair
Repairing or replacing damaged wiring in the control circuit.
- Total: $50 - $150
- Success rate: 85%
Money-Saving Tips for P0668
- Start with the most common and least expensive repairs first
- Use GeekOBD APP to confirm diagnosis before replacing expensive parts
- Consider preventive maintenance to avoid future occurrences
- Compare prices for OEM vs aftermarket parts based on your needs
- Address the issue promptly to prevent more expensive secondary damage
Diagnostic Steps
Professional P0668 Diagnosis Process
Follow these systematic steps to accurately diagnose P0668. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes)
Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes).
Step 2: Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes)
Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes).
Step 3: Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the intake manifold tuning valve and wiring (20-30 minutes)
Step 3: Component testing - Use a multimeter or specific diagnostic tools to test the intake manifold tuning valve and wiring (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation after any repairs and clear codes using the GeekOBD APP (10-15 minutes)
Step 4: System function test - Verify proper operation after any repairs and clear codes using the GeekOBD APP (10-15 minutes).
Step 5: Step 5: Road test verification - Drive vehicle under various conditions to confirm repair success (15-20 minutes)
Step 5: Road test verification - Drive vehicle under various conditions to confirm repair success (15-20 minutes).
Important Notes
- Always verify the repair with GeekOBD APP after completing diagnostic steps
- Clear codes and test drive to ensure the problem is resolved
- Address underlying causes to prevent code recurrence
Real Repair Case Studies
Case Study 1: Intake Manifold Tuning Valve Replacement on a 2016 Honda Civic
Vehicle: 2016 Honda Civic, 45,000 miles
Problem: Customer noticed engine hesitation and reduced fuel efficiency.
Diagnosis: After scanning with GeekOBD APP, P0668 was identified. The valve was tested and found to be stuck.
Solution: Replaced the intake manifold tuning valve and cleared the codes.
Cost: $250 (parts and labor included)
Result: Post-repair, the vehicle's performance improved significantly, and the check engine light remained off.
Case Study 2: Wiring Repair on a 2013 Ford F-150
Vehicle: 2013 Ford F-150, 80,000 miles
Problem: Check engine light with symptoms of rough idling.
Diagnosis: GeekOBD APP revealed P0668. A visual inspection found corroded wiring in the tuning valve circuit.
Solution: Repaired the damaged wiring and secured all connections.
Cost: $100 (parts and labor included)
Result: Engine performance returned to normal, with improved idle quality.