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DTC P1446 FUEL TANK SENSOR CONTROL VALVE CIRCUIT LOW

DTC P1446 FUEL TANK SENSOR CONTROL VALVE CIRCUIT LOW

OUTLINE OF DIAGNOSIS

Detect the open or short circuit of tank pressure switching solenoid.

Judge NG when the ECM output level is different from actual terminal level.

COMPONENT DESCRIPTION


(A)

Vent control (solenoid OFF)

(C)

During diagnostics (Solenoid ON)

(E)

Plug

(B)

Atmosphere

(D)

To pressure sensor



ENABLE CONDITION

Secondary Parameters Enable Conditions
None



GENERAL DRIVING CYCLE

Always perform the diagnosis continuously.

DIAGNOSTIC METHOD

Abnormality Judgment

Judge NG when the continuous time of completing the malfunction criteria below becomes more than 2.5 seconds.

Judgment Value

Malfunction Criteria Threshold Value
Battery voltage

≥ 10.9 V

After engine starting

1 second or more

Terminal output voltage when ECM sent OFF signals

Low

Ignition switch

ON



Time Needed for Diagnosis: 2.5 seconds

Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

Normality Judgment

Judge OK when the malfunction criteria below are completed.

Judgment Value

Malfunction Criteria Threshold Value
Battery voltage

≥ 10.9 V

After engine starting

1 second or more

Terminal output voltage when ECM sent OFF signals

High

Ignition switch

ON



DTC CLEAR CONDITION


When the OK idling cycle is completed 40 times in a row

When “Clear Memory” was performed


MALFUNCTION INDICATOR LIGHT CLEAR CONDITION


When the OK driving cycle is completed 3 times in a row

When “Clear Memory” was performed


FAIL SAFE

None

ECM OPERATION AT DTC SETTING

Memorize the freeze frame data. (For test mode $02)