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Home >> Nissan-Datsun >> 1999 >> Sentra XE L4-1597cc 1.6L DOHC MFI (GA16DE) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P1493

P1493




SYSTEM DESCRIPTION
This system controls the vacuum signal applied to the EVAP canister purge control valve. When the ECM detects any of the following conditions, current does not flow through the EVAP canister purge control solenoid valve. The solenoid valve cuts the vacuum signal so that the EVAP canister purge control valve remains closed.
- Ignition switch "ON"
- Closed throttle position
- Low engine coolant temperature
- During deceleration
- Engine stopped
- Low vehicle speed (M/T models)
- For 60 seconds after starting engine (After warm-up to normal operating temperature)

COMPONENT DESCRIPTION




EVAP canister purge control solenoid valve
The EVAP canister purge control solenoid valve responds to signals from the ECM. When the ECM sends an OFF signal, the vacuum signal (from the intake manifold to the EVAP canister purge control valve) is cut.
When the ECM sends an ON (ground) signal, the vacuum signal passes through the EVAP canister purge control solenoid valve. The signal then opens the EVAP canister purge control valve.




EVAP canister purge control valve
When the vacuum signal is cut by EVAP canister purge control solenoid valve, EVAP canister purge control valve closes.




EVAPORATIVE EMISSION SYSTEM DIAGRAM




CONSULT REFERENCE VALUE IN DATA MONITOR MODE




ECM TERMINALS AND REFERENCE VALUE
Specification data are reference values and are measured between each terminal and engine ground.




ON BOARD DIAGNOSIS LOGIC

DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCEDURE

CAUTION: Always drive vehicle at a safe speed.

NOTE:
- If DTC P1492 is displayed with P1493, perform TROUBLE DIAGNOSIS FOR DTC P1492 first.
- If "DTC CONFIRMATION PROCEDURE" has been previously conducted, always turn ignition switch "OFF" and wait at least 5 seconds before conducting the next test.







With Consult
1. Start engine and warm it up to normal operating temperature.
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 CONSULT.
5. Touch "START".
6. Start engine and let it idle for at least 90 seconds.
7. When the following conditions are met, "TESTING" will be displayed on the CONSULT screen. Maintain the conditions continuously until "TESTING" changes to "COMPLETED". (It will take approximately 30 seconds.)
Selector lever: Suitable position
Vehicle speed: 36 - 120 KPH (22 - 75 MPH)
CMPS.RPM (REF): 1,200 rpm or more (A/T) 1,600 rpm or more (M/T)
B/FUEL SCHDL: 1 - 4.5 msec
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 "DIAGNOSTIC PROCEDURE".

OR




With Generic Scan Tools
1. Start engine and warm it up to normal operating temperature.
2. Select "MODE 1" with GST
3. Check coolant temperature.
Coolant temperature: 40 - 100°C (104 - 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. Restart engine and let it idle for at least 100 seconds.
6. Maintain the following conditions for at least 30 seconds.
Gear position: Suitable gear position Vehicle speed: 36 - 120 KPH (22 - 75 MPH)
Engine speed: 1,200 rpm or more (A/T) 1,600 rpm or more (M/T)
Coolant temperature: 40 - 100°C (104 - 212°F)
7. Select "MODE 7" with GST
8. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

NOTE:
- Hold the accelerator pedal as steady as possible during driving in step 6).
- If the driving conditions are not satisfied in step 6), restart the procedure.
- It is better that the fuel level is low.

OR




Without Consult
1. Start engine and warm it up to normal operating temperature.
2. Check voltage between ECM terminal (51) and ground
Voltage: 0.8 - 1 .5 V
Perform the following procedure before the voltage drops below 0.8 V. If the voltage drops below 0.8 V, cool down the engine and perform the entire procedure all over again.
3. Turn ignition switch "OFF" and wait at least 5 seconds.
4. Restart engine and let it idle for at least 100 seconds.
5. Maintain the following conditions for at least 30 seconds.
Gear position: Suitable gear position Vehicle speed: 36 - 120 KPH (22 - 75 MPH)
Engine speed: 1,200 rpm or more (A/T) 1,600 rpm or more (M/T)
Check voltage between ECM terminal (51) and ground: 0.8 - 1.5 V
6. Stop the vehicle, turn ignition switch "OFF", wait at least 5 seconds, and then turn "ON".
7. Perform "Diagnostic Test Mode II (Self-diagnostic results)" with ECM.
8. If 1st trip DTC is detected, go to "DIAGNOSTIC PROCEDURE".

NOTE:
- Hold the accelerator pedal as steady as possible during driving in step 5).
If the driving conditions are not satisfied in step 5), restart the procedure.
- It is better that the fuel level is low.




DIAGNOSTIC PROCEDURE


COMPONENT INSPECTION
EVAP canister purge control solenoid valve










With Consult
1. Lift up driving wheels (M/T models only).
2. Turn ignition switch "ON".
3. Select "PURG CONT S/V" of "ACTIVE TEST" mode with CONSULT
4. Start engine and warm it up to normal operating temperature.
5. Disconnect vacuum hose at EVAP canister purge control valve.
6. Touch "ON" and "OFF" and check for vacuum passing through the hose.

OR







Without Consult
Check air passage continuity.
If NG or operation takes more than 1 second, replace solenoid valve.




EVAP canister purge control valve
Check EVAP canister purge control valve as follows.
1. Blow air in port (A) and (C) and ensure that there is no leakage.
2. Plug port (D) and blow air in port (B). Ensure that there is resistance to flow out of port (C).
3. Plug port (B) and blow air in port (D). Ensure that there is resistance to flow out of port (C).
4. Apply vacuum to port (A) [approximately -13.3 to -20.0 kPa (-100 to -150 mmHg, -3.94 to -5.91 inHg)].
Plug port (D) and blow air in port (C) and ensure free flow out of port (B).
Plug port (B) and blow air in port (C) and ensure free flow out of port (D).

EVAP canister vent control valve
Check air passage continuity.







With Consult
Perform "VENT CONTROL/V" in "ACTIVE TEST" mode with CONSULT.

OR







Without Consult
If NG or operation takes more than 1 second, clean valve using air blower or replace as necessary.
If the portion (B) is rusted, replace EVAP canister vent control valve.
Make sure new O-ring is installed properly.




Water separator
1. Check visually for insect's nests in the water separator air inlet.
2. Check visually for cracks or flaws in the appearance.
3. Check visually for cracks or flaws in the hose.
4. Check that (A) and (C) are not clogged by blowing air into (B) with (A), and then (C) plugged.
5. In case of NG in items 2 - 4, replace the parts.

NOTE: Do not disassemble water separator.
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