Egr Vacuum Regulator Solenoid; Exhaust Gas Recirculation (Egr) Function Control System (For 2.3L. 3.Ol. 4.Ol - Mazda B-Series 1997 Workshop Manual

FT
EXHAUST GAS RECIRCULATION (EGR) FUNCTION CONTROL SYSTEM
(FOR 2.3L 13.OL 14.OL)
EXHAUST GAS RECIRCULATION (EGR) FUNCTION CONTROL SYSTEM
(FOR 2.3L 13.OL 14.OL)
DESCRIPTION
This system recirculates a small amount of exhaust gas into the intake manifold to reduce the combustion
temperature and reduce the NOx emissions. This system consists of the EGR valve, EGR vacuum regu-
lator solenoid, differential pressure feedback EGR sensor, powertrain control module (PCM) and input
devices.
4BUOF3-167
Differential Pressure Feedback EGR Sensor
If the differential pressure feedback EGR sensor or circuit has an open or short, Diagnostic Trouble Code
No. P0400, P0401, P0402, P1400, P1401 or P I 408 is output.
If exhaust manifold side or intake manifold side hose is off or plugged, DTC No. Pi405 or PI406 is output.
6BUOFT-215
EGR Vacuum Regulator Solenoid
If the EGR vacuum regulator solenoid or circuit has an open or short, Diagnostic Trouble Code No. P1 409
is output.
If the circuit is open, no driveability symptom will be noticed.
If the circuit is shorted, the EGR valve will remain open, causing engine stalling and hard starting.
6BUOFT-216
DIFFERENT
PRESSURE
FEEDBACK
SENSOR
'IAL
EGR (DPFE)
DUTY CYCLE OUTPUT
EGR VACUUM
I
-
REGULATOR (EVR)
PCM SOLENOID
ANALOG
E E S H AIR
INPUT
I I
\
INTAKE
METERING
'
7
ORIFICE
VACUUM
4
1
I
EXHAUST PRESSURE
Operation
Cold engine (Coolant temperature
IS
less than 55 C (131-F))
EGR operailon 1 s stopped to Improve drlveabll~ty when the englne temperature
I S
cold
Warm Engtne
The powertra~ncontrol module IPCMI controls the EGR vacuum regulator solenod to supply EGR gases
EGR VACUUM REGULATOR SOLENOID
Inspection
1. Disconnect the vacuum hoses from the solenoid.
2. Connect the vacuum pump to the port A.
3. Plug the port B.
4. Apply the vacuum and make sure that the needle of the
vacuum pump stays at zero.