Leak Detector: Testing and Inspection

EVAP Leak Check Module Inspection

Check each component as follows.

NOTE: For operation of EVAP leak check module, refer to EVAP Leak Check System Description.

EVAP Canister Vent Valve Check

CAUTION:
- When checking EVAP canister vent valve, do not apply compressed air.
- Compressed air could damage EVAP leak check module and cause fuel vapor leaks.

1. Check coil resistance of EVAP canister vent valve between terminals "6" and "7" in EVAP leak check module.
If resistance is as specified, proceed to next step. If not, replace EVAP leak check module.

Coil resistance of EVAP canister vent valve : 25 - 30 Ohms at 20 °C (68 °F)






2. Remove EVAP leak check module (1) from EVAP canister.
3. Blow breath (2) into port (3). Air should come out of port (4). If not, replace EVAP leak check module.
4. Connect 12 V-battery to terminal "6" and terminal "7" of EVAP leak check module. Blow breath into port (3). Air should not come out of port (4).
If check result is not as specified above, replace EVAP leak check module.

WARNING: Do not suck air through valve. Fuel vapor inside valve is harmful.

CAUTION: Check to make sure that connection is made between correct terminals. Wrong connection can cause damage to EVAP canister vent valve in EVAP leak check module.






EVAP Leak Detection Pump Check

1. Check EVAP leak detection pump in EVAP leak check module as follows.
a. Connect a spherical plastic bag (1) with approximately 12.5 cm (4.92 in.) diameter (volume: 1L) to EVAP leak check module using a rubber band (2) as shown in figure.
b. Operate EVAP canister vent valve and EVAP leak detection pump by connecting 12 V battery to EVAP leak check module terminals as shown in figure.
c. Check that air in plastic bag is fully evacuated by EVAP leak detection pump within approximately 2 minutes. If check result is not as described above, replace EVAP leak check module.

CAUTION: Make sure that connection is made between correct terminals. Wrong connection can cause damage to EVAP canister vent valve and EVAP leak detection pump in EVAP leak check module.






EVAP Leak Check Pressure Sensor (Combine with BARO Sensor) Check

Check barometric pressure and reference vacuum pressure as follows.
1. Initial (barometric) pressure check:
a. Arrange 3 new 1.5 V batteries (1) in series and connect positive terminal to terminal "4" of EVAP leak check pressure sensor in EVAP leak check module and negative terminal to terminal "2".
b. Check EVAP leak check pressure sensor output voltage (barometric pressure signal voltage) between terminal "3" and "Ground" terminal.
If output voltage is out of specification, replace EVAP leak check module.
If output voltage is within specified value, go to Step 2).

CAUTION: Make sure that connection is made between correct terminals. Wrong connection can cause damage to EVAP leak check pressure sensor in EVAP leak check module.

EVAP leak check pressure sensor output voltage for initial (barometric) pressure (Terminal "4" voltage 4.5 - 5.5 V at ambient temperature of 20 - 30 °C (68 - 86 °F))











2. Reference vacuum pressure (reference orifice vacuum) check:
a. In the state of Step 1), operate EVAP leak detection pump by connecting 12 V-battery to terminal "1" and terminal "5" of EVAP leak check module. Check that pressure sensor output voltage (reference orifice vacuum) becomes lower than pressure sensor output voltage of Step 1) by approx. 0.1 V.
If sensor voltage is out of specification, replace EVAP leak check module.






EVAP Leak Check Module Visual Check

Check EVAP leak check module and its O-ring (1) for damage and deterioration.
If any faulty condition is found, replace module and/or O-ring.