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

Description

The P0077 trouble code indicates that the Engine Control Module (ECM) has detected a high voltage condition in the intake valve timing control solenoid circuit on Bank 1. The intake VVT solenoid controls oil flow to the variable valve timing system, helping optimize engine performance, fuel economy, and emissions.

Common Causes

Common causes include a faulty intake VVT solenoid, damaged wiring, corroded connectors, an open or shorted circuit, poor electrical connections, or in rare cases, a faulty ECM.

Symptoms

Typical symptoms include an illuminated Check Engine Light, rough idle, poor acceleration, reduced engine performance, and increased fuel consumption.

Estimated Repair Cost

The repair cost usually ranges from $20 to $250, depending on whether the issue is related to wiring, connectors, or replacement of the intake VVT solenoid.

Severity

Moderate. The vehicle is generally safe to drive for a short period, but delaying repairs can reduce engine efficiency and may lead to additional variable valve timing system issues.

Recommended Fix

Inspect the intake VVT solenoid, wiring, and electrical connectors. Repair any damaged wiring, replace the solenoid if necessary, ensure the engine oil is clean and at the correct level, then clear the diagnostic code and verify the repair.