EMISSION CONTROL
TSB Revision
ENGINE AND EMISSION CONTROL
17-63
ENGINE COOLANT TEMPERATURE SENSOR
CHECK
M1173008100426
To inspect these parts, refer to GROUP 13A, Multiport Fuel
Injection (MFI) Diagnosis
− Diagnostic Trouble Code chart
P.13Ab-22
.
INTAKE AIR TEMPERATURE SENSOR CHECK
M1173008200218
To inspect these parts, refer to GROUP 13A, Multiport Fuel
Injection (MFI) Diagnosis
− Diagnostic Trouble Code Chart
P.13Ab-22
.
FUEL TANK DIFFERENTIAL PRESSURE SENSOR
CHECK
M1173007700027
To inspect the sensor, refer to GROUP 13B, Fuel tank
− Fuel
tank inspection
P.13B-10
.
EVAPORATIVE EMISSION VENTILATION
SOLENOID CHECK
M1173007800080
Refer to GROUP 17, Evaporative emission canister and fuel
tank pressure relief valve
− Fuel tank pressure relief valve
inspection
P.17-69
.
EXHAUST GAS RECIRCULATION (EGR) SYSTEM
GENERAL DESCRIPTION (EGR SYSTEM)
M1173005200189
The exhaust gas recirculation (EGR) system lowers
the nitrogen oxide (NOx) emission level. When the
air/fuel mixture combustion temperature is high, a
large quantity of NOx is generated in the combustion
chamber. Therefore, this system recirculates part of
exhaust gas from the exhaust port of the cylinder
head to the combustion chamber through the intake
manifold to decrease the air/fuel mixture combustion
temperature, resulting in reduction of NOx. The EGR
flow rate is controlled by the EGR valve (Stepper
Motor) so as not to decrease the driveability.
OPERATION
When the engine coolant temperature is low, when
the engine is at idle or when a wide open throttle
operation is performed, the EGR valve (Stepper
Motor) is kept closed, achieving no EGR. After warm-
ing up of the engine, the EGR valve (Stepper Motor)
can be opened by the powertrain control module.
The powertrain control module monitors the EGR
system and illuminates the check engine/malfunction
indicator lamp to indicate that there is a malfunction.