EVAP system leak inspection using leak tester

1. Perform the following SST  (EVAP System Tester 134-01049A) self-test:
   NOTE:

   • If the tester does not work correctly during the self-test, refer to the tester operators manual .
   1. Verify that the control valve on the panel is in the HOLD position then open the nitrogen bottle valve.
   2. Connect the vehicle interface hose (part of the SST  ) to the SELF-TEST port located on the control panel. Hand tighten the fitting. (Do not overtighten.)
   3. Turn the control valve to the TEST position.
   4. The gauge should read 331-381 mm {13.1-15.0 in}  of water.
      • If the gauge is not reading in this range, adjust the pressure by turning the black knob on the low pressure regulator at the nitrogen bottle.
      Fig 1: Inspecting EVAP System Leak Using Leak Tester

      Courtesy of MAZDA MOTORS CORP.
   5. Turn the control valve to the HOLD position.
   6. Verify that the gauge holds pressure and that the flow meter reads no flow.
   • If there is no drop in pressure and no flow, the tester passes the self-test.
   • If the gauge leaks down, refer to the tester operators manual.
2. Connect the SST  to the vehicle.
   1. Verify that the control valve on the panel is in the HOLD position then open the nitrogen bottle valve.
   2. Remove the fuel-filler cap from the vehicle.
      • If the fuel-filler cap is not a MAZDA part or equivalent, replace it.
      NOTE:

      • INSPECT FUEL FILLER CAP AND FILLER NECK

      • Visually inspect for damage, insufficient sealing, rust, cracks or warps for filler cap and filler neck.
      • Repair or replace if necessary.
   3. Connect the receiver assembly (SST:  134-01059) to the vehicle cap test hose assembly (part of the SST  ) and the fuel-filler cap from the vehicle.
   4. Connect the cap adaptor (SST:  134-01058) to the vehicle cap test hose assembly (part of the SST  ) and to the fuel-filler neck.
   5. Connect the vehicle interface hose (part of the SST  ) to the center fitting of the vehicle cap test hose assembly (part of the SST  ).
   Fig 2: Inspecting Fuel Filler Cap And Filler Neck

   Courtesy of MAZDA MOTORS CORP.
3. Connect the M-MDS to the DLC-2.
4. Switch the ignition to ON (engine off).
5. Request the PCM on-board device control (Mode 08) using the M-MDS to close the canister vent value.
   NOTE:

   • The canister vent value is closed for 10 min  unless the following any actions are done:

   • The engine is started.
   • The ignition switch is turned off position.
6. Make sure the control valve on the 134-01049A is in the HOLD position and that the valve on the cylinder of nitrogen gas is open.
7. Turn the control valve to the open position and let the system fill. You should note a drop in the gauge pressure along with the flow meter being pegged at maximum flow for several minutes depending on how full or empty the fuel tank is, and how long it takes to completely fill and pressurize the EVAP system hoses.
8. If the gauge and the flow meter do not settle to a measurable level after 2-3 min  , then refer to the testers operators manual to verify that the canister vent valve is properly closed. If canister vent valve is properly closed. The EVAP system has large leakage. Check for leakage and repair as necessary.
9. Verify the pressure gauge and flow meter reading to determine if there is an EVAP leak:

NO EVAPORATIVE LEAK: 

• The flow meter registers "zero flow" and the pressure gauge returns to the pre-set pressure of 356 mm {14.0 in}  of water (H2O).

EVAPORATIVE LEAK: 

• The pressure does not return to the preset level of 356 mm {14.0 in}  of water (H2O) when measuring the flow. See setting leak standard for testing (.020 to.040 inch H2O) of the Evaporative Emissions Tester operators manual (134-01067).