DTC P0453: EVAP System (CPC) Pressure Sensor/Switch Circuit High: Notes

WARNING: This page is about a different variant/trim than selected.

1. -

DTC detecting condition: Immediately at fault recognition

Wiring diagram: Engine Electrical System Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>ENGINE ELECTRICAL SYSTEM .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DO (HEV))>GENERAL DESCRIPTION>PREPARATION TOOL>HOW TO USE CHECK BOARD .

NOTE: After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DO (HEV))>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

Courtesy of SUBARU OF AMERICA, INC.

CHECK DATA MONITOR .
1. Turn the ignition switch to OFF.
2. Press the fuel door release switch to open the fuel lid.
3. Wait for one minute or more.
4. Open the fuel cap.
5. Turn the ignition switch to ON.
6. Using the Subaru Select Monitor, read the value of [Fuel Tank Pressure Sensor] of the data monitor.
  NOTE: For detailed operation procedures, refer to "Common (Diagnostics)". Ref. to COMMON (DIAG)>DATA MONITOR .
  
  Is the value of [Fuel Tank Pressure Sensor] 2.65 [kPa] (19.88 mmHg, 0.78 inHg) or more?
  
  Yes: Go to 2.
  
  No: Even if (DTC is detected, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.
  
  NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
CHECK HARNESS BETWEEN ECM AND TANK PRESSURE SENSOR (OPEN) .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connector from the tank pressure sensor.
4. Measure the resistance of the harness between ECM connector and tank pressure sensor connector.
  Connector & terminal
  
  (B134) No. 54 - (AD93) No. 1:
  
  (B134) No. 59 - (AD93) No. 2:
  
  Is the resistance less than 1 Ω?
  
  Yes: Go to 3.
  
  No: Repair the harness and connector.
  NOTE:
  In this case, repair the following item:
  - Open circuit in harness between ECM connector and tank pressure sensor connector
  - Poor contact of coupling connector
  - Poor contact of J/C
CHECK FOR POOR CONTACT .
Check for poor contact of ECM and tank pressure sensor connector.

Is there poor contact in ECM and tank pressure sensor connector?

Yes: Repair the poor contact of ECM and tank pressure sensor connector.

No: Go to 4.
CHECK TANK PRESSURE SENSOR .
Check the tank pressure sensor. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO (HEV))>CIRCULATE TUBE ASSY>INSPECTION .

Is the check result OK?

Yes: Repair the short circuit to power supply in harness between ECM connector and tank pressure sensor connector.

No: Replace the circulate tube assembly. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO (HEV))>CIRCULATE TUBE ASSY .

NOTE: Tank pressure sensor cannot be disassembled.