ENGINE AND EMISSION CONTROL -
Engine and Emission Control System
<4D5-Step III>
17-4
FUNCTION CHECK
1. Start the engine and warm it up until the engine coolant
temperature reaches 65
_
C or above.
2. Race the engine by suddenly depressing the accelerator
pedal, then check that the EGR valve diaphragm lifts.
EGR SOLENOID VALVE OPERATION CHECK
1. Remove EGR solenoid valve Nos.1 and 2 connectors
and vacuum hoses.
2. Attach a vacuum pump to each nipple of the EGR solenoid
valve Nos. 1 and 2 and connect each connector of EGR
solenoid valve to battery and apply negative pressure.
Check that the valves are airtight both when voltage is
applied to each terminal of the EGR solenoid valve Nos.
1 and 2 and when it is not applied.
EGR solenoid valve No.1
Battery voltage
Normal condition
When current is
flowing
Vacuum leaks (Vacuum is maintained when
nipple B is plugged)
When current is not
flowing
Vacuum is maintained
EGR valve position sensor
EGR valve
Diaphragm
<EGR solenoid valve No.1>
A
B