Actron CP9087 Service Manual page 22

Section 2
What is it?
HIGH
SENSOR
VOLTAGE
LOW
MIN.
VALVE OPENING
How it is
Location
When to Test
What to
Inspect
2-14
Testing Sensors
FORD
EGR Valve
This sensor is a potentiometer - a type of variable
resistor (similar to a dashboard light dimmer
control). The computer supplies power and ground
to the sensor. the sensor has a shaft which is
pushed. When the sensor is mounted on the EGR
valve, the shaft gets pushed as the valve opens.
The sensor sends out a voltage signal indicating
the amount of valve opening ("lift"). The voltage
signal gets larger the more the valve is opened.
MAX.
The computer is programmed to provide optimum
EGR flow during idle, cruise, and hard acceleration
used?
operating conditions. The computer uses the
sensor signal to calculate actual EGR flow. Then
the computer can modify the EGR valve opening
as required.
Attached to the top of the EGR valve.
• Related trouble codes sent by computer.
• Driveability problems such as hesitation,
stumble, surging, poor fuel economy, erratic
acceleration, knocking (pinging), no torque
converter lock-up.
Sensor operation (see page 2-15). Poor connec-
tions at the sensor or computer. Damaged or
sticking EGR valve. Worn or broken vacuum
hoses, vacuum connectors. Damaged vacuum
reservoir, canister. Problems with control solenoids
supplying operating vacuum to open EGR valve.
HONDA
EGR Valve