DTC P0452: Evaporative Emission Control System Pressure Sensor Low Input

OUTLINE OF DIAGNOSIS
Detect the open or short circuit of tank pressure sensor.

Judge NG when out of the standard value.
COMPONENT DESCRIPTION

Fig 1: Identifying Evaporative Emission Control Conector And Terminal Voltage Graf (Low Input)
Courtesy of SUBARU OF AMERICA, INC.

ENABLE CONDITION

Secondary Parameters	Enable Conditions
Engine speed	"GREATER THAN EQUAL TO" 500 rpm
Battery voltage	"GREATER THAN EQUAL TO" 0V
After engine starting	2 seconds or more
Pressure control solenoid valve	Open
Drain valve	Close
Canister purge control solenoid valve duty ratio	"LESS THAN EQUAL TO"0%

GENERAL DRIVING CYCLE
Perform the diagnosis continuously in 2 seconds after starting the engine.

DIAGNOSTIC METHOD

Abnormality Judgment

Judge NG when the continuous time until completing all of the malfunction criteria below becomes more than time needed for diagnosis.

Judgment Value

JUDGMENT VALUE

Malfunction Criteria	Threshold Value
Output voltage	<0.2V

Time Needed for Diagnosis: 20 seconds

Malfunction Indicator Light Illumination: Illuminates as soon as malfunction occurs.

Normality Judgment

Judge OK and clear the NG when the malfunction criteria below are completed

Judgment Value

JUDGMENT VALUE

Malfunction Criteria	Threshold Value
Output voltage	"GREATER THAN EQUAL TO" .2V

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
Fix the fuel tank pressure at 0 kPa (0 mmHg, 0 inHg).
ECM OPERATION AT DTC SETTING
Memorize the freeze frame data. (For test mode $02)