Content .. 194 195 196 197 ..

Infiniti Q45 (FY33). Manual - part 196

SEF417U

SEF578Q

SEF418U

DIAGNOSTIC PROCEDURE

INSPECTION START

CHECK POWER SUPPLY.
1. Turn ignition switch “OFF”.
2. Disconnect EVAP canister purge vol-

ume control valve harness connector.

3. Turn ignition switch “ON”.
4. Check voltage between terminals

and engine ground with CONSULT-II

or tester.
Voltage: Battery voltage

Check the following.

Harness for open or
short between EVAP
canister purge volume
control valve and ECM
relay

Harness for open or
short between EVAP
canister purge volume
control valve and ECM

If NG, repair harness or
connectors.

CHECK OUTPUT SIGNAL CIRCUIT.
1. Turn ignition switch “OFF”.
2. Disconnect ECM harness connector.
3. Check harness continuity between

ECM terminal

and terminal

ECM terminal

and terminal

ECM terminal

and terminal

ECM terminal

and terminal

Continuity should exist.
If OK, check harness for short to
ground and short to power.

Replace harness or con-
nectors.

CHECK COMPONENT
(EVAP canister purge volume control
valve).
Refer to “COMPONENT INSPECTION” on
next page.

Replace EVAP canister
purge volume control
valve.

Perform “TROUBLE DIAGNOSIS FOR
INTERMITTENT INCIDENT”, EC-117.

INSPECTION END

IDX

TROUBLE DIAGNOSIS FOR DTC P0443

Evaporative Emission (EVAP) Canister Purge
Volume Control Valve (Circuit) (Cont’d)

EC-313

SEF353Q

SEC049C

SEF763P

SEF417U

COMPONENT INSPECTION

EVAP canister purge volume control valve

1. Disconnect EVAP canister purge volume control valve

harness connector.

2. Check resistance between the following terminals.

terminal

and terminals

terminal

and terminals

Resistance:

Approximately 35 - 43

Ω

[At 25°C (77°F)]

3. Reconnect EVAP canister purge volume control valve

harness connector.

4. Remove EVAP canister purge volume control valve

from intake manifold collector and disconnect hoses
from the valve.
(Plug the purge hoses. The EVAP canister purge vol-
ume control valve harness connector should remain
connected.)

5. Turn ignition switch “ON”.
6. Perform “PURG VOL CONT/V” in “ACTIVE TEST”

mode with CONSULT-II. Check that EVAP canister
purge volume control valve shaft moves smoothly for-
ward and backward according to the valve opening.
If NG, replace the EVAP canister purge volume control
valve.

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ OR ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

1. Disconnect EVAP canister purge volume control valve

harness connector.

2. Check resistance between the following terminals.

terminal

and terminals

terminal

and terminals

Resistance:

Approximately 35 - 43

Ω

[At 25°C (77°F)]

3. Reconnect EVAP canister purge volume control valve

harness connector.

4. Remove EVAP canister purge volume control valve

from intake manifold collector and disconnect hoses
from the valve.
(Plug the purge hoses. The EVAP canister purge vol-
ume control valve harness connector should remain
connected.)

5. Turn ignition switch “ON” and “OFF”. Check that EVAP

canister purge volume control valve shaft moves
smoothly forward and backward according to the igni-
tion switch position.
If NG, replace the EVAP canister purge volume control
valve.

TROUBLE DIAGNOSIS FOR DTC P0443

Evaporative Emission (EVAP) Canister Purge
Volume Control Valve (Circuit) (Cont’d)

EC-314

SEF032W

SEF419U

Evaporative Emission (EVAP) Canister Vent
Control Valve (Circuit)

COMPONENT DESCRIPTION

The EVAP canister vent control valve is located on the EVAP can-
ister and is used to seal the canister vent.
This solenoid (the EVAP canister vent control valve) responds to
signals from the ECM.
When the ECM sends an ON signal, the coil in the solenoid valve
is energized.
A plunger will then move to seal the canister vent. The ability to seal
the vent is necessary for the on board diagnosis of other evapora-
tive emission control system components.
This solenoid valve is used only for diagnosis, and usually remains
opened.
When the vent is closed, under normal purge conditions, the
evaporative emission control system is depressurized and allows
“EVAP Control System (Small Leak)” diagnosis.

CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE

Specification data are reference values.

MONITOR ITEM

CONDITION

SPECIFICATION

VENT CONT/V

Ignition switch: ON

OFF

ECM TERMINALS AND REFERENCE VALUE

Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring voltage. Doing so may result in damage to the
ECM’s transistor. Use a ground other than ECM terminals such as the body ground.

TER-

MINAL

NO.

WIRE

COLOR

ITEM

CONDITION

DATA

(DC Voltage)

P/B

EVAP canister vent con-
trol valve

Ignition switch “ON”

BATTERY VOLTAGE
(11 - 14V)

ON BOARD DIAGNOSIS LOGIC

Diagnostic

Trouble Code

No.

Malfunction is detected when ....

Check Items

(Possible Cause)

P0446
0903

An improper voltage signal is sent to ECM through
EVAP canister vent control valve.

Harness or connectors
(EVAP canister vent control valve circuit is open or
shorted.)

EVAP canister vent control valve

IDX

TROUBLE DIAGNOSIS FOR DTC P0446

EC-315

SEF392X

DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE

NOTE:
If “DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DURE” has just been completed, always turn ignition switch
“OFF” and wait at least 5 seconds before conducting the next
test.
TESTING CONDITION:
Before performing the following procedure, confirm battery
voltage is more than 11V at idle.

1) Turn ignition switch “ON”.
2) Select “DATA MONITOR” mode with CONSULT-II.
3) Start engine and wait at least 8 seconds.
4) If 1st trip DTC is detected, go to “DIAGNOSTIC

PROCEDURE”, EC-318.

Follow the procedure “With CONSULT-II” above.

TROUBLE DIAGNOSIS FOR DTC P0446

Evaporative Emission (EVAP) Canister Vent
Control Valve (Circuit) (Cont’d)

EC-316

Content .. 194 195 196 197 ..