P0077 Fault Code

Intake Valve Control Solenoid Circuit High (Bank 1)

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0077 fault code refers to an issue with the Intake Valve Control Solenoid Circuit High in Bank 1 of the vehicle's engine. This code is typically seen in vehicles with variable valve timing systems.

The Intake Valve Control Solenoid is responsible for controlling the intake valve timing, helping to optimize engine performance and fuel efficiency. When this solenoid circuit is detected as having a high voltage or resistance, the P0077 code is triggered.

The possible causes of a P0077 code include a faulty or damaged intake valve control solenoid, a wiring issue in the solenoid circuit, or a problem with the engine control module (ECM).

To diagnose and fix this issue, you can start by inspecting the wiring and connectors related to the intake valve control solenoid. Look for any signs of damage, corrosion, or loose connections. If any issues are found, they should be repaired or replaced as necessary.

If the wiring and connectors appear to be in good condition, it may be necessary to test the intake valve control solenoid itself. This can be done using a digital multimeter to check for the correct resistance and voltage levels.

If the solenoid is found to be faulty, it will need to be replaced. It's recommended to use OEM or high-quality aftermarket parts for the best results.

After any repairs or replacements are made, the fault code should be cleared from the ECM using a diagnostic scanner. This will allow you to check if the issue has been resolved.

If the P0077 code continues to appear after the appropriate repairs have been made, it may indicate a more complex issue with the ECM or other components of the engine control system. In such cases, it is advisable to seek assistance from a professional mechanic or dealership for further diagnosis and repair.

What are the symptoms of the P0077 code?

The P0077 fault code indicates a problem with the intake valve control solenoid circuit on Bank 1 of the engine. Here are some symptoms that may be associated with this fault code:

• Check Engine Light (CEL) is illuminated
• Decreased engine performance
• Engine misfires
• Rough idling
• Reduced fuel efficiency

If you experience any of these symptoms, it is recommended to have your vehicle diagnosed and repaired by a qualified mechanic to resolve the issue.

What causes the P0077 code?

P0077 - Intake Valve Control Solenoid Circuit High (Bank 1)

The P0077 fault code indicates an issue with the intake valve control solenoid circuit on bank 1 of the engine. This code is typically found in vehicles equipped with variable valve timing (VVT) systems.

Possible causes of the P0077 fault code include:

1. Faulty intake valve control solenoid: The solenoid may be stuck in the open position, allowing too much oil flow to the intake valve.
2. Wiring issues: There may be a short or open circuit in the wiring harness connecting the intake valve control solenoid.
3. Electrical connector problems: The connector that connects to the solenoid may be corroded, damaged, or not making a good connection.
4. Engine oil issues: Dirty or low-quality engine oil can cause problems with the solenoid's operation.

It is recommended to diagnose and repair the underlying issue causing the fault code. This may involve inspecting the intake valve control solenoid, checking the wiring and connector for any faults, and ensuring the engine oil is clean and at the proper level.

If you are not familiar with vehicle repairs, it is advisable to seek assistance from a professional mechanic to properly diagnose and fix the P0077 fault code.

How to fix P0077?

P0077 - Intake Valve Control Solenoid Circuit High (Bank 1)

This fault code indicates a problem with the intake valve control solenoid circuit on bank 1 of the engine. The solenoid is responsible for controlling the flow of intake air into the engine, and a high circuit voltage has been detected.

Possible Causes:

1. Faulty intake valve control solenoid.
2. Open or short circuit in the wiring harness.
3. Poor electrical connection at the solenoid or ECM (Engine Control Module).
4. Faulty ECM.

Diagnostic and Repair Steps:

1. Start by checking the electrical connections at the intake valve control solenoid and ECM. Ensure they are clean, secure, and free from corrosion.
2. Inspect the wiring harness for any signs of damage, such as worn insulation or loose connections. Repair or replace as necessary.
3. Test the intake valve control solenoid using a multimeter to check for proper resistance. Refer to the vehicle's service manual for the specific resistance values.
4. If the solenoid tests within the specified range, test the circuit voltage at the solenoid connector using a voltmeter. It should match the battery voltage or the reference voltage specified in the vehicle's service manual.
5. If the circuit voltage is high, it may indicate a faulty ECM. Consult the service manual for further diagnostic steps to confirm the ECM's condition.
6. If all the above steps do not resolve the issue, consider seeking professional help from a qualified mechanic or dealership.

It's important to note that this fault code can vary depending on the make and model of the vehicle. Always consult the vehicle's service manual or contact a professional for accurate diagnosis and repair instructions.