OBD Codes

P0029

Exhaust Valve Control Solenoid Circuit Range/Performance (Bank 2)

Moderatevariable valve

Overview

The P0029 diagnostic trouble code indicates a exhaust valve control solenoid circuit range/performance (bank 2) 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

  • Check Engine Light (MIL) illuminated
  • Poor fuel economy
  • Engine rattling noise on startup
  • Lack of power at certain RPM ranges

Common Causes

  • Clogged oil passages to VVT system
  • Worn timing chain or stretched chain
  • Faulty camshaft position sensor
  • Incorrect oil viscosity for the engine

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

Subaru OutbackHyundai Sonata (CVVT)Toyota Camry (2.5L)Kia Optima

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.