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DTC P0451 EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR RANGE/PERFORMANCE

DTC P0451 EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR RANGE/PERFORMANCE

OUTLINE OF DIAGNOSIS

Detect the tank pressure sensor output property abnormality.

Judge NG when there is no pressure variation, which should exist in the tank, considering the engine status.

COMPONENT DESCRIPTION


(1)

Connector

(A)

Output voltage

(2)

Terminal

(B)

Input voltage

(C)

To fuel tank

(D)

To atmospheric pressure switching solenoid



ENABLE CONDITION

Secondary Parameters Enable Conditions
After starting the engine

60 second or more

Fuel level

≥ 18litres (4.76 US gal, 3.96 Imp gal)

Fuel temperature

< 35°C (95°F)

Battery voltage

≥ 10.9 V

Atmospheric pressure

> 75.1 kPa (563 mmHg, 22.2 inHg)

Engine speed

< 6,500 rpm



GENERAL DRIVING CYCLE


Perform the diagnosis continuously in 60 seconds or more after starting the engine.

Be sure to check the fuel level and fuel temperature.


DIAGNOSTIC METHOD

Abnormality Judgment

Judge NG when the malfunction criteria below is completed.

Judgment Value

Malfunction Criteria Threshold Value
Number of times when the difference between the Max. fuel level and the Min., fuel level every 60 seconds is 2litres(0.53 US gal, 0.44 Imp gal) or more (with enable condition completed)

≥ 16 times

Max. − Min. tank pressure (with enable condition completed)

< 0.05 kPa (0.375 mmHg, 0.02 inHg)

Max. − Min. fuel temperature (with enable condition completed)

≥ 7°C (44.6 °F)



If the fuel level (Max. − Min.) in every 60 seconds is less than 2litres, extend 60 seconds more and make judgment with the Max. and Min. fuel level in 120 seconds.

If the difference did not appear though the time extended, extend the time (180, 240, 300 seconds) and continue the judgment.

Diagnosis counter will count up when the difference of fuel level (Max. − Min.) is more than 2litres.

Time Needed for Diagnosis: 1 second × 16 times or more

Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in two continuous drive cycles.

Normality Judgment

Judge OK when the malfunction criteria below is completed.

Judgment Value

Malfunction Criteria Threshold Value
Max. − Min. tank pressure

≥ 0.05 kPa (0.375 mmHg, 0.02 inHg)



DTC CLEAR CONDITION


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

When “Clear Memory” was performed


MALFUNCTION INDICATOR LIGHT CLEAR CONDITION


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

When “Clear Memory” was performed


FAIL SAFE

Purge control solenoid valve control: Purge fixation mode is prohibited.

ECM OPERATION AT DTC SETTING

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