Description
NHEC0821
SYSTEM DESCRIPTION
NHEC0821S01
Sensor
Input signal to ECM function
ECM
Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)
Engine speed
Intake valve
timing con-
trol
Intake valve timing control sole-
noid valve
Engine coolant temperature sensor
Engine coolant temperature
Vehicle speed sensor
Vehicle speed
SEC419D
This mechanism hydraulically controls cam phases continuously with the fixed operating angle of the intake
valve.
The ECM receives signals such as crankshaft position, camshaft position, engine speed, and engine coolant
temperature. Then, the ECM sends ON/OFF pulse duty signals to the camshaft timing control valve depend-
ing on driving status. This makes it possible to control the shut/open timing of the intake valve to increase
engine torque in low/mid speed range and output in high-speed range.
COMPONENT DESCRIPTION
NHEC0821S02
PBIB1842E
Intake valve timing control solenoid valve is activated by ON/OFF pulse duty (ratio) signals from the ECM.
The intake valve timing control solenoid valve changes the oil amount and direction of flow through intake valve
timing control unit or stops oil flow.
The longer pulse width advantages valve angle.
The shorter pulse width retards valve angle.
When ON and OFF pulse widths become equal, the solenoid valve stops oil pressure flow to fix the intake
valve angle at the control position.
GI
MA
EM
LC
FE
AT
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0011, P0021 IVT CONTROL
Description
EC-165