Inspection of Evaporative
Emission Controls
PURGE CONTROL
DIAPHRAGM VALVE
VACUUM PUMP/GAUGE
A973X-041-XXXXX
Disconnect vacuum hose from the
purge control diaphragm valve (on
the charcoal canister) and connect
a vacuum gauge to the hose.
Start the engine and allow it to
idle.
NOTE: Engine coolant tempera-
ture must be below 70°C
(158°F).
Is there vacuum ? Disconnect the 6P connector.
BLK/YEL
GRN
Measure voltage between BLK/
YEL (+) terminal and GRN (-) ter-
minal.
Is there battery voltage ?
Inspect vacuum hose
routing.
If OK. replace purge
cut-off solenoid valve.
Measure voltage between BLK/
YEL (+) terminal and body
ground.
(To page 11-138)(To page 11-138)
(cont’d)
Emission Control System
Evaporative Emission Controls (cont’d)
(From page 11-137)
Warm up the engine to normal
operating temperature (cooling
fan comes on).
(From page 11-137)
Is there battery voltage ?
Inspect GRIM wire for an open
between ECU (A20) and the
connector.
If wire is OK. substitute a
known-good ECU and recheck. If
symptom/incication goes away,
replace the orignal ECU.
Check for vacuum at #6 vacuum
hose after starting the engine:
Is there manifold vacuum? Disconnect the 6P connector.
Is there manifold vacuum?
Reconnect the hose.
Inspect for a short to body
ground in GRN wire between
ECU (A20) and the connector.
If wire is OK, substitute a
known-good ECU and recheck. If
symptom/indication goes away,
replace the original ECU.
Remove fuel filler cap.
(To page 11-139)
Inspect vacuum hose
routing.
If OK, replace purge
cut-off solenoid valve.
Repair open in BLK/
YEL wire between No.
2 fuse and the 6P con-
nector.
(From page 11-138)
Connect a vacuum gauge to can-
ister purge air hose.
PURGE
HOSE
Start the engine and raise speed to
3,500 rpm.
Does vacuum appear on gauge
within 1 minute ?
See two-way valve test to com-
plete.
Evaporative emission control are
OK.
Connect a vacuum gauge to the
canister purge hose and raise the
engine speed to 3,500 rpm.
Does vacuum appear on the
gauge?
Replace the canister.
(cont’d)
Inspect the purge hose
and throttle body port
for pinch or blockage.
PURGE AIR
HOSE
VACUUM/PRESSURE
GAUGE, 0-4 in. Hg
07 JAZ-001000 A