Infiniti Q45 (FY33). Manual - part 240

SEF809X

SEF811X

DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE

CAUTION:

Always drive vehicle at a safe speed.
NOTE:

If DTC P1492 is displayed with P1493, first perform
“TROUBLE DIAGNOSIS FOR DTC P1492”. Refer to
EC-482.

If “DIAGNOSTIC TROUBLE CODE CONFIRMATION PRO-
CEDURE” has been previously conducted, always turn
ignition switch “OFF” and wait at least 5 seconds before
conducting the next test.

1) Start engine and warm it up to normal operating tem-

perature.

2) Turn ignition switch “OFF” and wait at least 5 seconds.
3) Turn ignition switch “ON”.
4) Select “PURG CN/V & S/V P1493” of “EVAPORATIVE

SYSTEM” in “DTC WORK SUPPORT” mode with CON-
SULT-II.

5) Touch “START”.
6) Start engine (TCS switch “OFF”) and let it idle for at

least 90 seconds.

7) When the following conditions are met, “TESTING” will

be displayed on the CONSULT-II screen. Maintain the
conditions continuously until “TESTING” changes to
“COMPLETED”. (It will take approximately 30 seconds.)
Vehicle speed: 36 - 120 km/h (22 - 75 MPH)
CMPS-RPM (POS): 900 - 6,300 rpm
B/FUEL SCHDL: 2 - 4.8 msec
Selector lever: Suitable position

If “TESTING” is not displayed after 5 minutes, retry
from step 2).
8) Make sure that “OK” is displayed after touching “SELF-

DIAG RESULTS”. If “NG” is displayed, refer to “DIAG-
NOSTIC PROCEDURE”, EC-491.

SEF519R

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1) Start engine (TCS switch “OFF”) and warm it up to nor-

mal operating temperature.

2) Select “MODE 1” with GST.
3) Check coolant temperature.

Coolant temperature: 30 - 100°C (86 - 212°F)
Be sure that water temperature does not exceed 100°C.
If it becomes higher than 100°C, cool down the engine
and perform the procedure again from the beginning.

4) Turn ignition switch “OFF” and wait at least 5 seconds.
5) Turn ignition switch “ON” and wait at least 15 seconds.

IDX

TROUBLE DIAGNOSIS FOR DTC P1493

Evaporative Emission (EVAP) Canister Purge
Control Valve/Solenoid Valve (Cont’d)

EC-489

6) Restart engine and let it idle for at least 90 seconds.
7) Maintain the following conditions for at least 30 sec-

onds.
Vehicle speed: 36 - 120 km/h (22 - 75 MPH)
Engine speed : 900 - 6,300 rpm
Gear position : Suitable gear position
Coolant temperature: 30 - 100°C (86 - 212°F)

8) Select “MODE 7” with GST.
9) If 1st trip DTC is detected, go to “DIAGNOSTIC

PROCEDURE”, EC-491.

NOTE:

Hold the accelerator pedal as steady as possible during
driving in steps 7.

If the driving conditions are not satisfied in steps 7, restart
the procedure.

It is better that the fuel level is low.

SEF639U

1) Start engine (TCS switch “OFF”) and warm it up to nor-

mal operating temperature.

2) Check voltage between ECM terminal

and ground

Voltage: 3.12 - 0.8V
Perform the following procedure before the voltage
drops below 0.8V. If the voltage drops below 0.8V, cool
down the engine and perform the entire procedure all
over again.

3) Turn ignition switch “OFF” and wait at least 5 seconds.
4) Turn ignition switch “ON” and wait at least 15 seconds.
5) Restart engine and let it idle for at least 90 seconds.
6) Maintain the following conditions for at least 30 sec-

onds.
Vehicle speed: 40 - 120 km/h (25 - 75 MPH)
Engine speed : 1,000 - 2,100 rpm
Gear position : Suitable gear position
Check voltage between ECM terminal

and

ground: 3.12 - 0.8V

7) Stop the vehicle, turn ignition switch “OFF”, wait at least

5 seconds, and then turn “ON”.

8) Perform “Diagnostic Test Mode II (Self-diagnostic

results)” with ECM.

9) If 1st trip DTC is detected, go to “DIAGNOSTIC

PROCEDURE”, EC-491.

NOTE:

Hold the accelerator pedal as steady as possible during
driving in steps 6.

If the driving conditions are not satisfied in steps 6, restart
the procedure.

It is better that the fuel level is low.

TROUBLE DIAGNOSIS FOR DTC P1493

Evaporative Emission (EVAP) Canister Purge
Control Valve/Solenoid Valve (Cont’d)

EC-490

SEF594U

SEF622U

SEF765X

SEF596U

DIAGNOSTIC PROCEDURE

INSPECTION START

CHECK VACUUM SIGNAL.

1. Disconnect vacuum hose to

EVAP canister purge control
valve and install vacuum gauge.

2. Start engine.
3. Perform “PURG CONT S/V” in

“ACTIVE TEST” mode.

4. Select “ON” and “OFF” on CON-

SULT-II screen to turn on
“PURG CONT S/V”.

5. Check vacuum hose for vacuum

while revving engine up to 2,000
rpm.
ON: Vacuum should exist.
OFF: Vacuum should not

exist.

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

1. Start engine and warm it up to

normal operating temperature.

2. Stop engine.
3. Disconnect vacuum hose to

EVAP canister purge control
valve.

4. Install vacuum gauge and start

engine.

5. Check vacuum hose for vacuum

when revving engine up to 2,000
rpm.
ON: Vacuum should exist.
OFF: Vacuum should not

exist.

CHECK COMPONENTS
(EVAP canister purge con-
trol solenoid valve).
Refer to “COMPONENTS
INSPECTION” on next
page.

Check vacuum hoses for
improper connection, clog-
ging or disconnection.
Refer to Vacuum Hose
Drawing”, EC-19.

CHECK COMPONENT
(EVAP canister vent control valve).
Refer to “COMPONENTS INSPECTION”,
EC-493.

Replace EVAP canister
vent control valve and/or
water separator.

CHECK IF EVAP CANISTER IS SATU-
RATED WITH WATER.
1. Remove EVAP canister with vent con-

trol valve attached.

2. Check if water drains from the EVAP

canister.
If it will, weigh the EVAP canister with
the vent control valve attached.
If the weight is:

More than 1.8 kg (4.0 lb)

→

Less than 1.8 kg (4.0 lb)

→

Replace EVAP canister
and check the following.
1. Check hose connections

to the EVAP canister
and water separator for
clogging and poor con-
nection.

2. Check water separator.

Refer to “COMPONENT
INSPECTION”, EC-493.

CHECK COMPONENT
(EVAP canister purge control valve).
Refer to “COMPONENT INSPECTION”,
EC-493.

Replace EVAP canister
purge control valve.

(Go to next page.)

IDX

TROUBLE DIAGNOSIS FOR DTC P1493

Evaporative Emission (EVAP) Canister Purge
Control Valve/Solenoid Valve (Cont’d)

EC-491

SEF427U

CHECK COMPONENT
(EVAP control system pressure sensor).
1. Check disconnection of hose connected

to the sensor.

2. Check sensor harness connector for

water soak.
Water should not exist.
If OK, go to step 3.

3. Check EVAP control system pressure

sensor, refer to “COMPONENT
INSPECTION”, EC-320.

Replace EVAP control sys-
tem pressure sensor and
repair or replace harness
and connector.

CHECK EVAPORATIVE EMISSION LINE.
Check EVAP purge line hoses for leak or
clogging.
Refer to “Evaporative Emission Line
Drawing”, EC-29.

Repair EVAP purge line
hoses.

INSPECTION END

SEF765X

SEF400W

SEF313Q

COMPONENT INSPECTION

EVAP canister purge control solenoid valve

1. Turn ignition switch “ON”.
2. Select “PURG CONT S/V” of “ACTIVE TEST” mode

with CONSULT-II.

3. Start engine and warm it up to normal operating tem-

perature.

4. Disconnect vacuum hose at EVAP canister purge con-

trol valve.

5. Touch “ON” and “OFF” and check for vacuum passing

through the hose.

Condition

Vacuum

Idle

Not exist

2,000 rpm

Exist

Check air passage continuity.

Condition

Air passage

continuity

between

and

Air passage

continuity

between

and

12V direct current supply
between terminals

Yes

No supply

Yes

If NG or operation takes more than 1 second, replace solenoid
valve.

TROUBLE DIAGNOSIS FOR DTC P1493

Evaporative Emission (EVAP) Canister Purge
Control Valve/Solenoid Valve (Cont’d)

EC-492

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