DTC P0452 Evaporative Emission Control System Pressure Sensor Low Input

WARNING: This page is about a different car, the 2006 Subaru Outback. However, it is still accessible from the selected car via links, so may be relevant.

DTC DETECTING CONDITION:

Immediately at fault recognition
GENERAL DESCRIPTION < Ref. to DTC P0452 EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR LOW INPUT , Diagnostic Trouble Code (DTC) Detecting Criteria. >

CAUTION: After repair or replacement of faulty parts, perform Clear Memory Mode < Ref. to OPERATION , Clear Memory Mode. > and Inspection Mode < Ref. to PROCEDURE , Inspection Mode. >.

WIRING DIAGRAM:

Fig 1: Evaporative Emission Control System Pressure Sensor - Wiring Diagram

DTC P0452 EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR LOW INPUT - DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK CURRENT DATA. Turn the ignition switch to OFF. Remove the fuel filler cap. Install the fuel filler cap. Turn the ignition switch to ON. Read the data of fuel tank pressure sensor signal using Subaru Select Monitor. NOTE: Subaru Select Monitor For detailed operation procedure, refer to "READ CURRENT DATA FOR ENGINE". < Ref. to SUBARU SELECT MONITOR . >	Is the measured value less than -2.8 kPa (-21.0 mmHg, -0.827 inHg)?	Go to step 2.	Even if the malfunction indicator light illuminates, the circuit has returned to a normal condition at this time.
2 CHECK POWER SUPPLY TO FUEL TANK PRESSURE SENSOR. Measure the voltage between ECM connector and chassis ground. Connector & terminal (B135) No. 22 (+) - Chassis ground (-):	Is the voltage more than 4.5 V?	Go to step 4.	Go to step 3.
3 CHECK POWER SUPPLY TO FUEL TANK PRESSURE SENSOR. Measure the voltage between ECM connector and chassis ground. Connector & terminal (B135) No. 22 (+) - Chassis ground (-):	Is the voltage more than 4.5 V?	Repair the poor contact of ECM connector.	Contact with SOA Service Center.
4 CHECK INPUT SIGNAL OF ECM. Measure the voltage between ECM and chassis ground. Connector & terminal (B135) No. 32 (+) - Chassis ground (-):	Is the voltage less than 0.2 V?	Go to step 6.	Go to step 5.
5 CHECK INPUT SIGNAL FOR ECM (USING SUBARU SELECT MONITOR). Read the data of fuel tank pressure sensor signal using Subaru Select Monitor. NOTE: Subaru Select Monitor For detailed operation procedure, refer to "READ CURRENT DATA FOR ENGINE". < Ref. to SUBARU SELECT MONITOR . >	Does the measured value change by shaking the ECM harness and connector?	Repair the poor contact of ECM connector.	Go to step 6.
6 CHECK HARNESS BETWEEN ECM AND COUPLING CONNECTOR IN REAR WIRING HARNESS. Turn the ignition switch to OFF. Remove the rear seat cushion. Separate rear wiring harness and fuel tank cord. Turn the ignition switch to ON. Measure the voltage between the rear wiring harness connector and chassis ground. Connector & terminal (R15) No. 7 (+) - Chassis ground (-):	Is the voltage more than 4.5 V?	Go to step 7.	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between ECM and rear wiring harness connector Poor contact in coupling connector
7 CHECK HARNESS BETWEEN ECM AND COUPLING CONNECTOR IN REAR WIRING HARNESS. Turn the ignition switch to OFF. Disconnect the connectors from ECM. Measure the resistance of harness between ECM and rear wiring harness connector. Connector & terminal (B135) No. 30 - (R15) No. 4:	Is the resistance less than 1 Ω?	Go to step 8.	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between ECM and rear wiring harness connector Poor contact in coupling connector Poor contact in joint connector
8 CHECK HARNESS BETWEEN ECM AND COUPLING CONNECTOR IN REAR WIRING HARNESS. Measure the resistance of harness between rear wiring harness connector and chassis ground. Connector & terminal (R15) No. 4 - Chassis ground:	Is the resistance more than 1 MΩ?	Go to step 9.	Repair the ground short circuit of harness between ECM and rear wiring harness connector.
9 CHECK FUEL TANK CORD. Disconnect the connector from fuel tank pressure sensor. Measure the resistance of fuel tank cord. Connector & terminal (R57) No. 7 - (R47) No. 3:	Is the resistance less than 1 Ω?	Go to step 10.	Repair the open circuit in fuel tank cord.
10 CHECK FUEL TANK CORD. Measure the resistance of fuel tank cord. Connector & terminal (R57) No. 4 - (R47) No. 1:	Is the resistance less than 1 Ω?	Go to step 11.	Repair the open circuit in fuel tank cord.
11 CHECK FUEL TANK CORD. Measure the resistance of harness between fuel tank pressure sensor connector and engine ground. Connector & terminal (R47) No. 2 - Chassis ground:	Is the resistance more than 1 MΩ?	Go to step 12.	Repair the ground short circuit of fuel tank cord.
12 CHECK POOR CONTACT. Check for poor contact in fuel tank pressure sensor connector.	Is there poor contact in fuel tank pressure sensor connector?	Repair the poor contact in fuel tank pressure sensor connector.	Replace the fuel tank pressure sensor. < Ref. to FUEL TANK PRESSURE SENSOR . >