Evaporative Emissions System: Testing and Inspection

Neutral Switch Connector:

SYSTEM OPERATION

NOTE: Check the condition of the wiring harness and/or vacuum lines and connectors before checking the sensors or switches.

1. Disconnect the neutral switch connector (M/T) and connect a jumper wire to both terminals of the connector (wiring harness side).

EC-AT Control Unit Location:

2. Start the engine, then disconnect the EC-AT (Electronically Controlled Automatic Transmission) control unit.

NOTE: Disconnect the EC-AT control unit connector after starting the engine.

Vacuum Pump Connection -- Purge Control Valve:

3. Disconnect the vacuum hose from the No. 1 purge control valve, and connect vacuum pump tester.
4. Check that no vacuum is present when cold (coolant temp: below 550C [131°F] ).
5. Warm up the engine to normal operating temperature, and increase the engine speed.
6. Check for vacuum.

Engine speed Vacuum

Below approx. 900 rpm No
Above approx. 900 rpm Yes

7. Reconnect the vacuum hose to the No. 1 purge control valve and cool down the engine.

Vacuum Pump Connection -- Vacuum Switching Valve:

8. Disconnect the evaporative gas hose from the vacuum switch valve port, and plug the hose.
9. Connect a vacuum pump tester to the vacuum switch valve.
10. Check that no vacuum is present when cold (coolant temp: below 70°C [158°F]
11. Warm up the engine to normal operating temperature, and increase the engine speed.
12. Check for movement of the needle on the vacuum pump tester.

Engine speed Needle

Below 1,500 rpm Does not move

Above 1,500 rpm Acceleration Fluctuation
Other Does not move

13. Stop the engine and reconnect the evaporative gas hose to the vacuum switch valve.
14. Reconnect the neutral switch connector.

NOTE: Reconnect the EC-AT control unit connector, and disconnect the negative battery cable for at least 5 sec. to erase the malfunction code.

EVAPORATIVE LINE

Vacuum Pump Connection -- Evaporative Pipe:

1. Disconnect the evaporative hose from the evaporative pipe.
2. Connect the vacuum pump tester to the evaporative pipe.
3. Start the engine.
4. Operate the vacuum pump and verify that no vacuum is held. If vacuum is held, check the separator and check and cut valve.
5. Disconnect the vacuum pump tester, and reconnect the evaporative hose to the evaporative pipe.