Air Only Test

Test the EVAP system using the decay or leak down testing method with "Air only test".
NOTE:
- Using the low-pressure or right side of the machine, determine if the system leaks by pressurizing the system with air using the Air only test.
- On low-pressure, the fixed pressure is less than one half of one percent.
- The air only test must be done first because the vapor test generates heat that can increase pressure and affect the accuracy of the pressure gauge.
- Always perform the air only test before the vapor test.

Move the vehicle to a location where safety can be assured.
Ignition switched ON (engine off).
Access the following PIDs using the M-MDS. (See PCM INSPECTION .)
- EVAPCV
Remove the fuel-filler cap from the vehicle and clean the fuel-filler cap installation surface of the vehicle.
Install the gas cap single thread to the fuel-filler cap installation surface.

Courtesy of MAZDA MOTORS CORP.
NOTE:
- If the gas cap single thread does not fit to the fuel-filler cap installation surface, use the universal filler neck connector.
- EVAP test tools for older vehicles (1998-2013 MY) are available via eStore.
Courtesy of MAZDA MOTORS CORP.
Insert the EVAP/low pressure vapor output hose nozzle into the gas cap single thread hose as shown in the figure.

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Toggle the power supply switch to the right to turn on the EVAP/low pressure testing (right side of tester) and verify that the green lamp turns on.

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Verify that the flow control valves for the EVAP/low pressure testing (right side of tester) and turbo/high pressure testing (left side of tester) are OFF.

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Press the [AIR ONLY TEST] button in the center of the tester and verify that the blue lamp turns on.

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Turn the EVAP/low pressure flow control valve for the EVAP/low pressure testing (right side of tester) to ON to send air to the EVAP system.

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Verify that the flow meter for the EVAP/low pressure testing (right side of tester) indicates the maximum flow rate.

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Set the CV solenoid valve (simulation item: EVAPCV) to ON using the M-MDS.
Verify that the indication of the flow meter for the EVAP/low pressure testing (right side of tester) decreases to the minimum flow rate.

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- If the flow meter indication does not decrease to the minimum flow rate, it means that there is leakage in the EVAP system. Perform the vapor test. (See Vapor test .)
Turn the EVAP/low pressure flow control valve for the EVAP/low pressure testing (right side of tester) to OFF.

Courtesy of MAZDA MOTORS CORP.
Read and record the value indicated by the system pressure gauge for the EVAP/low pressure testing (right side of tester).

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Leave the tester for 2 min.
Read the value indicated by the system pressure gauge again and check if there is any change from the value recorded in Step 15.
There is no change in the value
- The EVAP system is normal in the passage between the fuel-filler cap installation surface and the purge solenoid valve, or between the charcoal canister and the CV solenoid valve.
  - Perform inspections of the following part because malfunctions can be considered with them.
- Fuel-filler cap (See FUEL-FILLER CAP INSPECTION .)
There is change in the value
- The EVAP system has a malfunction between the fuel-filler cap and the purge solenoid valve, or between the charcoal canister and the CV solenoid valve.
  - Perform the vapor test. (See Vapor test .)