Celica Corolla Echo Highlander L Cyl Mr Prius

The VVT system controls intake camshaft valve timing to provide improved engine performance, fuel economy, and reduced exhaust emissions. VVT system consists of camshaft timing oil control valve, variable valve timing controller on intake camshaft, crankshaft position sensor, Engine Control Module (ECM), camshaft position sensor and associated wiring. See Fig. 73 -Fig. 75 .

NOTE: Camshaft timing oil control valve may also be referred to as oil control valve for VVT, VVT Oil Control Valve (OCV) or camshaft timing oil control valve VVT. Variable valve timing controller may also be referred to as variable valve timing actuator or VVT controller.

Intake and exhaust camshaft are driven by a timing chain and drive gear on each camshaft. Intake camshaft drive gear is integrated with the variable valve timing controller to vary intake camshaft valve timing. Variable valve timing controller consists of a housing which is driven from the timing chain and a vane that is fixed on the intake camshaft. See Fig. 76 . Oil pressure may be delivered from advance or retard side of intake camshaft to the variable valve timing controller. This oil pressure causes variable valve timing controller to rotate, causing intake camshaft to rotate and change the valve timing. When engine is stopped, to improve stability,

2001 ENGINE PERFORMANCE Theory & Operation intake camshaft remains in the most retarded state. When no oil pressure is applied to variable valve timing controller immediately after engine is started, lock pin prevents movement of variable valve timing controller to prevent a knocking noise. Once engine is started and oil pressure exists at variable valve timing controller, the lock pin is released by the oil pressure.

Camshaft timing oil control valve is an electrically controlled valve that receives oil pressure from the oil pump. See Fig. 72 . The ECM uses input signals for engine speed, intake air volume, throttle position and engine coolant temperature to determine operation of camshaft timing oil control valve. The ECM also uses input signals from camshaft position sensor and crankshaft position sensor for determining the actual intake camshaft valve timing. Camshaft position sensor may also be referred to as variable valve timing sensor. The ECM operates camshaft timing oil control valve by controlling position of spool valve. This determines which side of variable valve timing controller the oil pressure will be applied to for advancing or retarding the valve timing by rotating the intake camshaft. See Fig. 72 . When engine is stopped, camshaft timing oil control valve is in the retarded state.

When engine is idling, intake camshaft valve timing remains at the standard or hold position to stabilize the idle and obtain better fuel economy. During light engine load, intake camshaft valve timing remains retarded to provide stable engine operation. During medium engine load, intake camshaft valve timing is advanced to provide increased performance, fuel economy and improved emission control. During heavy engine load in low-to-medium-speed range, intake camshaft valve timing is advanced to provide increased torque. During heavy engine load in high-speed range, intake camshaft valve timing is retarded to provide improved high-speed range operation and better fuel economy. During cold temperatures, intake camshaft valve timing is set at the standard or hold position to stabilize fast idle speed and obtain better fuel economy. When engine is started or stopped, intake camshaft valve timing is remains at retarded position to improve engine starting.

If a problem exists in the VVT system, a Diagnostic Trouble Code (DTC) may be stored in ECM. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article for retrieving of DTCs.

2001 ENGINE PERFORMANCE Theory & Operation

2001 Corolla Timing
Fig. 73: Identifying Variable Valve Timing System Components (Celica, Corolla & MR2) Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

2001 ENGINE PERFORMANCE Theory & Operation

Toyota Celica 2001 Timing Mark
Fig. 74: Identifying Variable Valve Timing System Components (ECHO & Prius) Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

2001 ENGINE PERFORMANCE Theory & Operation

Timing Chain Toyota Corolla 2001
Fig. 75: Identifying Variable Valve Timing System Components (Highlander 2.4L 4-Cyl. & RAV4) Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

2001 ENGINE PERFORMANCE Theory & Operation

Rav4 Valve Timing Adjustment

Fig. 76: Identifying Variable Valve Timing Controller Components (Celica, Corolla, ECHO, Highlander

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Fig. 76: Identifying Variable Valve Timing Controller Components (Celica, Corolla, ECHO, Highlander

Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.

Get My Free Ebook


Responses

  • ambessa eyob
    How to install engine chain corolla 00?
    6 years ago
  • kati
    Where is the valve timing on 2001 sienna?
    6 years ago
  • rafael
    How to time the chain toyota corolla 2006?
    6 years ago
  • henrik
    Does a 1989 toyota corolla have a timing chain?
    6 years ago
  • Abrha Amanuel
    How to fix timing chain of toyota echo?
    6 years ago
  • chris
    How to remove timing chain on toyota corolla?
    6 years ago
  • Eglantine
    How to replace the timing chain on a toyota yaris?
    6 years ago
  • taija
    How to set the timing chain on a Toyota Yaris 2001?
    5 years ago
  • jyri
    How to change a 91 corolla door?
    5 years ago
  • Rowan
    Where are the timing chain mark for 2001 toyota camry?
    5 years ago
  • Keiren
    How does the timing chain goes toyota corolla 2001?
    5 years ago
  • ROSS MARRERO
    How do i put timing chain on 2007 toyota yaris vvt i?
    5 years ago
  • Ermanno
    Where is the variable valve time sensor corolla 01?
    5 years ago
  • adelchi
    How to adjust and install camshaft timing oil control valve toyota 2001 corolla?
    5 years ago
  • thomas
    How to set timming on a 92 celica st?
    5 years ago
  • Gabrielle
    How to change timing belt on toyota celica 2001 gt?
    4 years ago
  • Fiyori
    Where is the variable valve timing for 2004 toyota?
    4 years ago
  • eleleta
    How to fix 2003 rav4 motor timing belt diagram?
    4 years ago
  • Rose
    How to replace oil control valvu for 2000 rav4?
    3 years ago
  • petros
    How I can set time in chainToyota vanza2008?
    2 years ago
  • john
    How to time a timing belt on rav 4?
    2 years ago
  • cara
    How to set timing belt for toyota corolla 16 valve?
    2 years ago
  • michael
    How to replace a cold start valve toyota celica?
    2 years ago
  • jennifer
    Where is the variable valve control located in a 2000 toyota corolla 4 cylinder?
    2 years ago
  • Alicia
    How to retard the time on a Toyota echo?
    1 year ago
  • brad
    How to set Toyota Camry timing system?
    12 months ago
  • marmadoc
    How to set timing in toyota corolla with photos?
    11 months ago
  • gustavo
    How to set cam timing for toota corolla?
    10 months ago
  • christin
    How to fix a Timing belt Toyota rav4?
    9 months ago
  • tuomas
    How to set timing chain of ran4?
    7 months ago
  • lea
    How the timing marks of toyota hilux is position?
    3 months ago
  • mandy
    How to do timing on a toyota yaris photos?
    3 months ago
  • fausta
    How to assemble toyota vitz timing chain?
    2 months ago
  • christian
    How to change toyota highlander 2004 timing cam?
    1 month ago

Post a comment