DTC P0023: "B" Camshaft Position Actuator Control Circuit/Open Bank 2: Notes

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

-
DTC detecting condition:

Immediately at fault recognition

Trouble symptom:

Improper idling

Wiring diagram:

Engine Electrical System Ref. to WIRING SYSTEM (IMPREZA MODEL)>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>ENGINE ELECTRICAL SYSTEM>WIRING DIAGRAM .
- IMPREZA MODEL
Courtesy of SUBARU OF AMERICA, INC.
- CROSSTREK MODEL
Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Use the check board when measuring the ECM terminal voltage and resistance. Ref. to ENGINE (DIAGNOSTICS) (H4DO 2.0 (EXCEPT FOR 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 2.0 (EXCEPT FOR HEV))>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

CHECK OUTPUT SIGNAL OF ECM .
1. Turn the ignition switch to ON.
2. Measure the voltage between ECM connector and chassis ground.
  Connector and terminal
  
  (E158) No. 109 (+) - Chassis ground (-):
  
  Is the voltage 10 V or more?
  
  Yes: Go to 2.
  
  No: Go to 3.
CHECK FOR POOR CONTACT .
Check for poor contact of ECM connector.

Is there poor contact of ECM connector?

Yes: Repair the poor contact of ECM connector.

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 POWER SUPPLY TO THE EXHAUST OIL CONTROL SOLENOID LH .
Measure the voltage between exhaust oil control solenoid LH connector and engine ground.

Connector and terminal

(E66) No. 1 (+) - Engine ground (-):

Is the voltage 10 V or more?

Yes: Go to 4.

No: Repair the power supply circuit.
CHECK HARNESS BETWEEN ECM AND EXHAUST OIL CONTROL SOLENOID LH .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connector from the exhaust oil control solenoid LH.
4. Turn the ignition switch to ON.
5. Measure the voltage between ECM connector and chassis ground.
  Connector and terminal
  
  (E158) No. 109 (+) - Chassis ground (-):
  
  Is the voltage 10 V or more?
  
  Yes: Repair the short circuit to power supply in harness between ECM connector and exhaust oil control solenoid LH connector.
  
  No: Go to 5.
CHECK HARNESS BETWEEN ECM AND EXHAUST OIL CONTROL SOLENOID LH (SHORT TO GROUND) .
1. Turn the ignition switch to OFF.
2. Disconnect the connector from ECM.
3. Disconnect the connector from the exhaust oil control solenoid LH.
4. Measure the resistance between exhaust oil control solenoid LH connector and engine ground.
  Connector and terminal
  
  (E66) No. 2 - Engine ground:
  
  Is the resistance 1 MΩ or more?
  
  Yes: Go to 6.
  
  No: Repair the short circuit to ground in harness between ECM connector and exhaust oil control solenoid LH connector.
CHECK HARNESS BETWEEN ECM AND EXHAUST OIL CONTROL SOLENOID LH (OPEN) .
Measure the resistance of harness between ECM connector and exhaust oil control solenoid LH.

Connector and terminal

(E158) No. 109 - (E66) No. 2:

Is the resistance less than 1 Ω?

Yes: Go to 7.

No: Repair the harness and connector.
NOTE:
In this case, repair the following item:
- Open circuit in harness between ECM connector and exhaust oil control solenoid LH connector
- Poor contact of coupling connector
CHECK EXHAUST OIL CONTROL SOLENOID LH .
Measure the resistance between exhaust oil control solenoid LH terminals.

Terminals

No. 1 - No. 2:

Is the resistance 6 - 12 Ω?

Yes: Repair the poor contact of exhaust oil control solenoid LH connector.

No: Replace the exhaust oil control solenoid LH. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DO (EXCEPT FOR HEV))>OIL CONTROL SOLENOID .