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DTC P0448 EVAPORATIVE EMISSION CONTROL SYSTEM VENT CONTROL CIRCUIT SHORTED

DTC P0448 EVAPORATIVE EMISSION CONTROL SYSTEM VENT CONTROL CIRCUIT SHORTED

DTC DETECTING CONDITION:


• Two consecutive driving cycles with fault

• GENERAL DESCRIPTION


Important

After repair or replacement of faulty parts, conduct Clear Memory Mode and Inspection Mode .


WIRING DIAGRAM:


CHECK INPUT SIGNAL FOR ECM.

Turn ignition switch to OFF.

Connect the test mode connector at the lower portion of instrument panel (on the driver’s side).

Turn ignition switch to ON.

While operating the drain valve, measure voltage between ECM and chassis ground.

Note

Drain valve operation can be executed using Vehicle Diagnostic Interface. For the procedure, refer to “Compulsory Valve Operation Check Mode”.


Connector & terminal

(B84) No. 11 (+) — Chassis ground (−):

Does the resistance change within 0 — 10 V?

Yes


No

The malfunction indicator light may light up, however, the circuit is returned to the normal status at the moment. In this case, repair poor contact in ECM connector.


CHECK INPUT SIGNAL FOR ECM.

Turn ignition switch to ON.

Measure the voltage between ECM and chassis ground.

Connector & terminal

(B84) No. 11 (+) — Chassis ground (−):

Is the voltage more than 10 V?

Yes


No


CHECK FOR POOR CONTACT.

Check for poor contact in ECM connector.

Is there poor contact in ECM connector?

Yes

Repair poor contact in ECM connector.


No

Replace the ECM.


CHECK HARNESS BETWEEN DRAIN VALVE AND ECM CONNECTOR.

Turn ignition switch to OFF.

Disconnect the connector from drain valve.

Turn ignition switch to ON.

Measure the voltage between ECM and chassis ground.

Connector & terminal

(B84) No. 11 (+) — Chassis ground (−):

Is the voltage more than 10 V?

Yes

Repair short circuit to battery in harness between ECM and drain valve connector. After repair, replace the ECM.


No


CHECK DRAIN VALVE.

Turn ignition switch to OFF.

Measure the resistance between drain valve terminals.

Terminals

No. 1 — No. 2:

Is the resistance less than 1 Ω?

Yes

Replace the drain valve and ECM .


No


CHECK FOR POOR CONTACT.

Check for poor contact in ECM connector.

Is there poor contact in ECM connector?

Yes

Repair poor contact in ECM connector.


No

Replace the ECM.