OBD Codes

P1085

VVT Control Low Voltage (Bank 1) (Toyota)

Moderatevariable valve

Overview

The P1085 diagnostic trouble code indicates a vvt control low voltage (bank 1) (toyota) condition. This code relates to the variable valve timing (VVT) system, which adjusts camshaft timing for optimal performance across the engine's RPM range. VVT issues often stem from oil quality or flow problems and can cause rough idle, poor performance, and decreased fuel economy.

Symptoms

  • Reduced engine power and acceleration
  • Rough idle or engine hesitation
  • Oil light flickering on dashboard
  • Stalling at idle

Common Causes

  • Dirty or low engine oil
  • Incorrect oil viscosity for the engine
  • Clogged oil passages to VVT system
  • Failed VVT phaser/actuator

Diagnosis Steps

  1. 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
  2. 2Check engine oil level and condition; change oil if dirty or incorrect viscosity
  3. 3Test the VVT solenoid (oil control valve) with a multimeter
  4. 4Inspect the VVT solenoid screen/filter for debris or sludge
  5. 5Monitor camshaft position sensor data using scan tool live data

Estimated Repair Cost

$150$1,000

Cost varies by vehicle, location, and repair shop. Includes parts and labor.

Commonly Affected Vehicles

Honda Civic (VTEC)Toyota Camry (2.5L)Hyundai Sonata (CVVT)Nissan Altima (VVT)

Related Codes

More Variable Valve Codes

Frequently Asked Questions

Yes, dirty or low-quality engine oil is one of the leading causes of VVT system problems. Oil sludge can clog the VVT solenoid screen and oil passages, preventing proper cam timing adjustment.