Cat C15 Referencias

Troubleshooting
C15 On-highway Engines
Media Number -RENR5088-06

Publication Date -01/07/2007

Date Updated -10/07/2007

i02818906

Intake Valve Actuator Response - Test
SMCS - 5479-038-IL

System Operation Description:
The Intake Valve Actuation system (IVA) uses pressurized engine oil to delay the closing
of the intake valves. The system is controlled by the Engine ControlModule (ECM). The
system contains the following components:
Check Valve (3) - Pressurized engine oil flows to a rail inside the valve cover base. A
check valve prevents oil from flowing from the rail back to the main oil gallery.
Pressure Sensor (2) - A pressure sensor is threaded into the rail. The sensor converts the
rail pressure into an electrical signal. The ECM monitors the signal in orderto determine
the pressure of the oil in the rail.
Control Valve (1) - A control valve is threaded into the rail. The control valve contains a
coil and a cartridge assembly. The cartridge assembly contains a spool. The spool is
normally closed. When the spool is closed, the oil is contained in the rail. The ECM
sends a signal to the coil in order to fully open the spool. The oil is releasedinto the space
underneath the valve cover and the rail pressure is reduced.
Actuator (4) - The actuators are located under the valve covers. Pressurized engine oil
flows from the rail to each actuator. The actuators use the pressurized engine oil and
electrical commands from the ECM in order to delay the closing of the intake valves.

View Image

Illustration 1
Component location on atypical C11 or C13 engine
(1) Control valve
(2) Pressure sensor
(3) Check valve
(4) Actuators
View Image

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Illustration 2

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Component location on a typical C15 engine
(1) Control valve
(2) Pressure sensor
(3) Check valve
(4) Actuators

System Operation During Engine Start
The ECM performs the following sequence of operations every time the engine is started:







The ECM commands the control valve to open for 17 seconds.
The ECM checks the temperature of the coolant.
The ECM commands the control valve to close when the coolant temperature
exceeds 20 °C (68 °F). This allows the temperature of the oil in the rail to warm
up.
The ECM commands the control valve to open. The ECM samples the rail
pressure. The ECM commands the controlvalve to close. The ECM takes a
second sample of the rail pressure. The ECM compares the two pressure values.
The ECM activates a 283-7 code if the pressure difference is too low.
The control valve should remain closed during engine operation.

System Operation During Engine Operation

The system does not operate until the engine has reached normal operating temperature.

View ImageIllustration 3
Section view of the components
(4) Actuator
(5) Space
(6) Solenoid
(7) Piston
(8) Rocker arm
(9) Valve

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(10) Rail
(11) Intake valves

Each actuator (4) contains two solenoids (6) . Each solenoid is connected to a valve (9) .
The solenoid is normally de-energized. The valve is normally open. This allows oil to
flow between rail (10) and the space (5) abovepiston (7) .
Rocker arm (8) is down when the intake valves are open. Pressurized oil flows from rail
(10) to space (5) above piston (7) . This causes the piston to move down. The piston
contacts rocker arm (8) .
The ECM energizes solenoid (6) when the ECM requires intake valves (11) to remain
open. The energized solenoid closes valve (9) . This traps the oil in space (5) . The
trapped oilcauses piston (7) and rocker arm (8) to remain down. This keeps intake valves
(11) open.
The ECM de-energizes solenoid (6) when the ECM requires the intake valves to close.
The de-energized solenoid lifts valve (9) . Valve springs (9) raise intake valves (11) ,
rocker arm (8) , and piston (7) . The rising piston forces the oil from space (5) into rail
(10) .
The flow of oil into the rail...