Engine Controls - Engine (Diagnostics) (H4SO): Diagnosis

INSPECTION

Before performing diagnostics, check the following item which might affect engine problems.

MODE $01: (CURRENT POWERTRAIN DIAGNOSTIC DATA)

Refer to data denoting the current operating condition of analog input/output, digital input/output or the powertrain system.

A list of the support data and PID (Parameter Identification) codes are shown in the following chart.

PID	Data	Unit of measure
$01	Number of emission-related powertrain DTC, and malfunction indicator light status and diagnosis support information
$03	Fuel system control status
$04	Calculated engine load value	%
$05	Engine coolant temperature	°C
$06	Short term fuel trim	%
$07	Long term fuel trim	%
$0B	Intake manifold absolute pressure	KPa
$0C	Engine speed	RPM
$0D	Vehicle speed	MPH
$0E	Ignition timing advance	O
$0F	Intake air temperature	°C
$10	Air flow rate from mass air flow sensor	G/sec
$11	Throttle valve absolute opening angle	%
$13	Check whether oxygen sensor is installed.
$15	Oxygen sensor output voltage and short term fuel trim associated with oxygen sensor (Bank 1 Sensor 2)	V and %
$1C	Supporting OBD system
$1F	Elapsed time after starting the engine	Sec
$21	Travel distance after the malfunction indicator light illuminates	Miles
$24	A/F value and A/F sensor output voltage (Bank 1 Sensor 1)	And V
$2C	Target EGR	%
$2D	EGR deviation	%
$2E	Evaporative purge	%
$2F	Fuel level	%
$30	Number of warm ups after DTC clear
$31	Travel distance after DTC clear	Miles
$32	Fuel tank pressure	Pa
$33	Barometric pressure	KPa
$34	A/F value and A/F sensor current (Bank 1 Sensor 1)	And mA
$3C	Catalyst temperature #1	°C
$41	Diagnostic monitor of each drive cycle
$42	ECM power voltage	V
$43	Absolute load	%
$44	A/F target lambda
$45	Relative throttle opening angle	%
$46	Ambient temperature	°C
$47	Absolute throttle opening angle 2	%
$49	Absolute accelerator opening angle 1	%
$4A	Absolute accelerator opening angle 2	%
$4C	Target throttle opening angle	%
$4D	Engine operating time while malfunction indicator lit	Min
$4E	Elapsed time after DTC clear	Min
$51	Fuel used
$5A	Relative accelerator opening angle	%

POWERTRAIN DIAGNOSTIC DATA REFERENCE CHART

Note. Refer to general scan tool manufacturer's instruction manual to access generic OBD-II PIDs (MODE $01).

Refer to "List of Diagnostic Trouble Code (DTC)" for information about data denoting emission-related powertrain DTC. Refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

Refer to the mode used to clear or reset emission-related diagnostic information (OBD-II trouble diagnostic information).

Note. Refer to general scan tool manufacturer's instruction manual to clear the emission-related diagnostic information (MODE $04).

GENERAL SCAN TOOL

Refer to data denoting emission-related powertrain DTC.

For details concerning DTC, refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

Note. Refer to general scan tool manufacturer's instruction manual to access powertrain DTC (MODE $03).

PREPARATION FOR THE INSPECTION MODE

Check that the battery voltage is 12 V or more and fuel remains approx. half [20 - 40 l (5.3 - 10.6 US gal, 4.4 - 8.8 Imp gal)].
Lift up the vehicle using a garage jack and place it on rigid racks, or drive the vehicle onto free rollers.

WARNING

Before lifting up the vehicle, ensure parking brakes are applied. Do not use a pantograph jack in place of a rigid rack. Secure a rope or wire to the front or rear towing hooks to prevent the lateral runout of front wheels. Before rotating the wheels, make sure that there is no one in front of the vehicle. Besides while the wheels are rotating, make sure that no one approaches the vehicle front side. Make sure that there is nothing around the wheels. For AWD model, pay special attention to all four wheels. While servicing, do not depress or release the clutch pedal or accelerator pedal quickly regardless of the engine speed. Quick operation may cause the vehicle to drop off the free roller. To prevent the vehicle from slipping due to vibration, do not place anything between rigid rack and the vehicle.

Scheme 1

Scheme 2

After clearing the memory, check for any remaining unresolved trouble data. Refer to «CLEAR MEMORY MODE»(ref-325319-S04489388682009071800000) .
Warm up the engine.
Prepare the Subaru Select Monitor kit. Refer to «PREPARATION TOOL»(ref-325319-S06557699802009071800000) , General Description.
Prepare the personal computer which has been installed the Subaru Select Monitor.
Connect the USB cable between SDI (Subaru Diagnosis Interface) and USB port on the personal computer (dedicated port for the Subaru Select Monitor). NOTE: The dedicated port for the Subaru Select Monitor means the USB port which was used to install the Subaru Select Monitor.
Connect the diagnosis cable to the SDI.
Connect the delivery (test) mode connector (A) located under the glove box.
Connect the SDI to data link connector located in the lower portion of the instrument panel (on the driver's side). CAUTION: Do not connect any scan tools except Subaru Select Monitor and general scan tool.
Start up the personal computer.
Turn the ignition switch to ON (engine OFF), and run the "PC application for Subaru Select Monitor".
On the «Main Menu» display screen, select the {Each System Check}.
On the «System Selection Menu» display screen, select the {Engine Control System}.
Click the [OK] button after the information of engine type has been displayed.
On the «Engine Diagnosis» display screen, select the {Dealer Check Mode Procedure}.
When the «Perform Inspection (Dealer Check) Mode» is shown on the screen, click the [Next] button.
Perform subsequent procedures as instructed on the display screen.

If trouble still remains in the memory, the corresponding DTC appears on the display screen.

Note. For detailed operation procedure, refer to the PC application help for Subaru Select Monitor. For details concerning DTC, refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . Release the parking brake. The speed difference between front and rear wheels may illuminate the ABS warning light, but this does not indicate a malfunction. When engine control diagnosis is finished, perform the ABS memory clearance procedure of self-diagnosis function. Refer to CLEAR MEMORY MODE .

After performing the diagnostics and clearing the memory, check for any remaining unresolved trouble data. Refer to «CLEAR MEMORY MODE»(ref-325319-S04489388682009071800000) .
Warm up the engine.
Connect the delivery (test) mode connector (A) located under the glove box.
Connect the general scan tool to data link connector located in the lower portion of the instrument panel (on the driver's side). CAUTION: Do not connect any scan tools except Subaru Select Monitor and general scan tool.
Start the engine. NOTE: Ensure the select lever is placed in "P" range before starting. (AT model) Depress the clutch pedal when starting engine. (MT model)
Turn the neutral position switch to ON using select lever or shift lever.
Depress the brake pedal to turn the brake switch ON. (AT model)
Keep the engine speed in 2,500 - 3,000 RPM range for 40 seconds.
Place the select lever or shift lever in D position (AT model) or 1st gear (MT model) and drive the vehicle at 5 to 10 km/h (3 to 6 MPH). NOTE: For AWD model, release the parking brake. The speed difference between front and rear wheels may illuminate the ABS warning light, but this indicates no malfunctions. When engine control diagnosis is finished, perform the ABS memory clearance procedure of self-diagnosis system. Refer to «CLEAR MEMORY MODE»(ref-325329-S06975763402009071800000) .
Using the general scan tool, check DTC and record the result(s).

Note. For detailed operation procedures, refer to the general scan tool operation manual. For details concerning DTC, refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

For clear memory procedures using the general scan tool, refer to General Scan Tool Instruction Manual.

Note. Initial diagnosis of electronic throttle control is performed after memory clearance. For this reason, start the engine after 10 seconds or more have elapsed since the ignition switch was turned to ON.

DIAGNOSIS

The malfunction indicator light circuit is open or shorted.

TROUBLE SYMPTOM

When the ignition switch is turned to ON (engine OFF), malfunction indicator light does not come on.

Scheme 3

Scheme 3: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK OUTPUT SIGNAL OF ECM . Turn the ignition switch to ON. Measure the voltage between ECM connector and chassis ground. Connector & terminal (B136) No. 11 (+) - Chassis ground (-)	Is the voltage less than 1 V?	Go to step 4 .	Go to step 2 .
2 CHECK POOR CONTACT . Check for poor connection by shaking or pulling ECM connector and harness.	Does the malfunction indicator light illuminate?	Repair poor contact of the ECM connector.	Go to step 3 .
3 CHECK ECM CONNECTOR . Check the connection of ECM connector.	Is the ECM connector correctly connected?	Replace the ECM. Refer to ENGINE CONTROL MODULE (ECM) .	Repair the connection of ECM connector.
4 CHECK HARNESS BETWEEN COMBINATION METER AND ECM CONNECTOR . Turn the ignition switch to OFF. Remove the combination meter. Refer to COMBINATION METER . Disconnect the connector from ECM and combination meter. Measure the resistance of harness between ECM and combination meter connector. Connector & terminal (B136) No. 11 - (i10) No. 38	Is the resistance less than 1 ohms?	Go to step 5 .	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit of harness between ECM and combination meter connector Poor contact of coupling connector
5 CHECK POOR CONTACT . Check for poor contact of combination meter connector.	Is there poor contact in combination meter connector?	Repair the poor contact of combination meter connector.	Go to step 6 .
6 CHECK HARNESS BETWEEN COMBINATION METER AND IGNITION SWITCH CONNECTOR . Turn the ignition switch to ON. Measure the voltage between combination meter connector and chassis ground. Connector & terminal (i10) No. 2 (+) - Chassis ground (-)	Is the voltage 10 V or more?	Replace the combination meter circuit board. Refer to COMBINATION METER .	Check the following item and repair if necessary. NOTE: Blown out of fuse (No. 5) Open or short circuit in harness between fuse (No. 5) and battery terminal Poor contact of ignition switch connector

NOTE
In this case, repair the following item: Open circuit of harness between ECM and combination meter connector Poor contact of coupling connector

NOTE
Blown out of fuse (No. 5) Open or short circuit in harness between fuse (No. 5) and battery terminal Poor contact of ignition switch connector

DIAGNOSIS PROCEDURE CHART

The malfunction indicator light circuit is shorted.

Although malfunction indicator light illuminates when the engine runs, DTC is not shown on the Subaru Select Monitor display.

The malfunction indicator light circuit is open or shorted.
The delivery (test) mode connector circuit is open.

Malfunction indicator light does not blink during Inspection Mode.

Scheme 4

Scheme 4: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK STATUS OF MALFUNCTION INDICATOR LIGHT . Turn the ignition switch to OFF. Disconnect the delivery (test) mode connector. Turn the ignition switch to ON. (engine OFF)	Does the malfunction indicator light illuminate?	Go to step 2 .	Repair the malfunction indicator light circuit. Refer to MALFUNCTION INDICATOR LIGHT DOES NOT COME ON , Malfunction Indicator Light.
2 CHECK HARNESS BETWEEN COMBINATION METER AND ECM CONNECTOR . Turn the ignition switch to OFF. Disconnect the connectors from the ECM. Turn the ignition switch to ON.	Does the malfunction indicator light illuminate?	Repair the ground short circuit of harness between ECM and combination meter connector.	Go to step 3 .
3 CHECK HARNESS BETWEEN DELIVERY (TEST) MODE CONNECTOR AND ECM . Turn the ignition switch to OFF. Disconnect the connectors from the ECM. Measure the resistance of harness between delivery (test) mode connector and ECM. Connector & terminal (B76) No. 1 - (B136) No. 6: (B75) No. 1 - (B135) No. 27	Is the resistance less than 1 ohms?	Go to step 4 .	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit of harness between ECM and delivery (test) mode connector Poor contact of joint connector
4 CHECK POOR CONTACT . Check for poor contact of the ECM connector.	Is there poor contact in ECM connector?	Repair poor contact of the ECM connector.	Replace the ECM. Refer to ENGINE CONTROL MODULE (ECM) .

NOTE
In this case, repair the following item: Open circuit of harness between ECM and delivery (test) mode connector Poor contact of joint connector

DIAGNOSIS PROCEDURE CHART

The delivery (test) mode connector circuit is shorted.

Malfunction indicator light blinks when delivery (test) mode connector is not connected.

Open or short circuit in data link connector

Subaru Select Monitor communication failure

Scheme 5

Scheme 5: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK POWER SUPPLY CIRCUIT . Connect the SDI (Subaru Diagnosis Interface) or general scan tool to data link connector.	Does SDI or general scan tool turn ON?	Go to step 4 .	Go to step 2 .
2 CHECK POWER SUPPLY CIRCUIT . Measure the voltage between data link connector and chassis ground. Connector & terminal (B40) No. 16 (+) - Chassis ground (-)	Is the voltage 10 V or more?	Go to step 3 .	Repair the power supply circuit. NOTE: In this case, repair the following item: Open or ground short circuit of harness between battery and data link connector Blown out of fuse (M/B No. 13)
3 CHECK HARNESS BETWEEN DATA LINK CONNECTOR AND CHASSIS GROUND . Turn the ignition switch to OFF. Measure the resistance of harness between data link connector and chassis ground. Connector & terminal (B40) No. 4 - Chassis ground: (B40) No. 5 - Chassis ground	Is the resistance less than 5 ohms?	Repair the poor contact of data link connector.	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit of harness between ECM and data link connector Open circuit of harness between ECM and engine ground Poor contact in ECM connector Poor contact of coupling connector
4 CHECK HARNESS BETWEEN ECM AND DATA LINK CONNECTOR . Disconnect the connector from ECM, TCM, VDC CU, airbag CM and body integrated unit. CAUTION: When disconnecting the connector from air-bag control module, always follow the precautions on AB article. Refer to CAUTION , General Description. Measure the resistance of harness between ECM and data link connector. Connector & terminal (B136) No. 16 - (B40) No. 7	Is the resistance less than 1 ohms?	Go to step 5 .	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit of harness between ECM and data link connector Poor contact of coupling connector
5 CHECK HARNESS BETWEEN ECM AND DATA LINK CONNECTOR . Measure the resistance between data link connector and chassis ground. Connector & terminal (B40) No. 7 - Chassis ground	Is the resistance 1 Mohms or more?	Repair the poor contact in the ECM or data link connector.	Repair the ground short circuit of harness between ECM and data link connector.

NOTE
In this case, repair the following item: Open or ground short circuit of harness between battery and data link connector Blown out of fuse (M/B No. 13)

NOTE
In this case, repair the following item: Open circuit of harness between ECM and data link connector Open circuit of harness between ECM and engine ground Poor contact in ECM connector Poor contact of coupling connector

CAUTION
When disconnecting the connector from air-bag control module, always follow the precautions on AB article. Refer to CAUTION , General Description.

NOTE
In this case, repair the following item: Open circuit of harness between ECM and data link connector Poor contact of coupling connector

DIAGNOSIS PROCEDURE CHART

DTC DETECTING CONDITION

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0026 INTAKE VALVE CONTROL SOLENOID CIRCUIT RANGE/PERFORMANCE (BANK 1)»(ref-325332-S37870121332009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 6

Scheme 6: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN ECM AND VARIABLE VALVE LIFT DIAGNOSIS OIL PRESSURE SWITCH . Warm up the engine. Turn the ignition switch to OFF. Disconnect the connectors from the ECM and variable valve lift diagnosis oil pressure switch. Measure the resistance of harness between ECM and variable valve lift diagnosis oil pressure switch connector. Connector & terminal (B134) No. 31 - (E71) No. 1	Is the resistance less than 1 ohms?	Go to step 2 .	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between ECM and variable valve lift diagnosis oil pressure switch connector Poor contact of coupling connector
2 CHECK HARNESS BETWEEN ECM AND VARIABLE VALVE LIFT DIAGNOSIS OIL PRESSURE SWITCH . Measure the resistance between the variable valve lift diagnosis oil pressure switch connector and engine ground. Connector & terminal (E71) No. 1 - Engine ground	Is the resistance 1 Mohms or more?	Go to step 3 .	Repair the ground short circuit of harness between ECM and variable valve lift diagnosis oil pressure switch connector.
3 CHECK HARNESS BETWEEN ECM AND VARIABLE VALVE LIFT DIAGNOSIS OIL PRESSURE SWITCH . Turn the ignition switch to ON. Measure the voltage between the variable valve lift diagnosis oil pressure switch connector and engine ground. Connector & terminal (E71) No. 1 (+) - Engine ground (-)	Is the voltage 10 V or more?	Repair the short circuit to power of the harness between the ECM and variable valve lift diagnosis oil pressure switch connector.	Go to step 4 .
4 CHECK DTC . Perform the Clear Memory Mode. After idling the engine, check the DTC. NOTE: For detailed procedures, refer to CLEAR MEMORY MODE .	Is DTC displayed?	Replace the oil switching solenoid valve. Refer to OIL SWITCHING SOLENOID VALVE . Go to step 5 .	END
5 CHECK DTC . Perform the Clear Memory Mode. After idling the engine, check the DTC. NOTE: For detailed procedures, refer to CLEAR MEMORY MODE .	Is DTC displayed?	Check for oil routing.	END.

NOTE
In this case, repair the following item: Open circuit in harness between ECM and variable valve lift diagnosis oil pressure switch connector Poor contact of coupling connector

NOTE
For detailed procedures, refer to CLEAR MEMORY MODE .

NOTE
For detailed procedures, refer to CLEAR MEMORY MODE .

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0028 INTAKE VALVE CONTROL SOLENOID CIRCUIT RANGE/PERFORMANCE (BANK 2)»(ref-325332-S31819276512009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 7

Scheme 7: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN ECM AND VARIABLE VALVE LIFT DIAGNOSIS OIL PRESSURE SWITCH . Warm up the engine. Turn the ignition switch to OFF. Disconnect the connectors from the ECM and variable valve lift diagnosis oil pressure switch. Measure the resistance of harness between ECM and variable valve lift diagnosis oil pressure switch connector. Connector & terminal (B134) No. 32 - (E72) No. 1	Is the resistance less than 1 ohms?	Go to step 2.	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between ECM and variable valve lift diagnosis oil pressure switch connector Poor contact of coupling connector
2 CHECK HARNESS BETWEEN ECM AND VARIABLE VALVE LIFT DIAGNOSIS OIL PRESSURE SWITCH . Measure the resistance between the variable valve lift diagnosis oil pressure switch connector and engine ground. Connector & terminal (E72) No. 1 - Engine ground	Is the resistance 1 Mohms or more?	Go to step 3 .	Repair the ground short circuit of harness between ECM and variable valve lift diagnosis oil pressure switch connector.
3 CHECK HARNESS BETWEEN ECM AND VARIABLE VALVE LIFT DIAGNOSIS OIL PRESSURE SWITCH . Turn the ignition switch to ON. Measure the voltage between the variable valve lift diagnosis oil pressure switch connector and engine ground. Connector & terminal (E72) No. 1 (+) - Engine ground (-)	Is the voltage 10 V or more?	Repair the short circuit to power of the harness between the ECM and variable valve lift diagnosis oil pressure switch connector.	Go to step 4 .
4 CHECK DTC . Perform the Clear Memory Mode. After idling the engine, check the DTC. NOTE: For detailed procedures, refer to CLEAR MEMORY MODE .	Is DTC displayed?	Replace the oil switching solenoid valve. Refer to OIL SWITCHING SOLENOID VALVE . Go to step 5 .	END
5 CHECK DTC . Perform the Clear Memory Mode. After idling the engine, check the DTC. NOTE: For detailed procedures, refer to CLEAR MEMORY MODE .	Is DTC displayed?	Check for oil routing.	END.

NOTE
In this case, repair the following item: Open circuit in harness between ECM and variable valve lift diagnosis oil pressure switch connector Poor contact of coupling connector

NOTE
For detailed procedures, refer to CLEAR MEMORY MODE .

NOTE
For detailed procedures, refer to CLEAR MEMORY MODE .

DIAGNOSIS PROCEDURE CHART

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0030 HO2S HEATER CONTROL CIRCUIT (BANK 1 SENSOR 1)»(ref-325332-S42490032092009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 8

Scheme 8: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR . Start and warm up the engine. Turn the ignition switch to OFF. Disconnect the connectors from the ECM and front oxygen (A/F) sensor. Measure the resistance of harness between ECM and front oxygen (A/F) sensor connector. Connector & terminal (B136) No. 2 - (E23) No. 4: (B136) No. 3 - (E23) No. 4	Is the resistance less than 1 ohms?	Go to step 2 .	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between ECM and front oxygen (A/F) sensor connector Poor contact of coupling connector
2 CHECK HARNESS BETWEEN ECM AND FRONT OXYGEN (A/F) SENSOR CONNECTOR . Measure the resistance of harness between ECM and front oxygen (A/F) sensor connector. Connector & terminal (B135) No. 9 - (E23) No. 1: (B135) No. 8 - (E23) No. 3	Is the resistance less than 1 ohms?	Go to step 3 .	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between ECM and front oxygen (A/F) sensor connector Poor contact of coupling connector
3 CHECK FRONT OXYGEN (A/F) SENSOR . Measure the resistance between front oxygen (A/F) sensor terminals. Terminals No. 6 - No. 4	Is the resistance between 2 - 3 ohms?	Go to step 4 .	Replace the front oxygen (A/F) sensor. Refer to FRONT OXYGEN (A/F) SENSOR .
4 CHECK POOR CONTACT . Check poor contact of ECM and front oxygen (A/F) sensor connector.	Is there poor contact in ECM or front oxygen (A/F) sensor connector?	Repair the poor contact of ECM or front oxygen (A/F) sensor connector.	Replace the front oxygen (A/F) sensor. Refer to FRONT OXYGEN (A/F) SENSOR .

NOTE
In this case, repair the following item: Open circuit in harness between ECM and front oxygen (A/F) sensor connector Poor contact of coupling connector

NOTE
In this case, repair the following item: Open circuit in harness between ECM and front oxygen (A/F) sensor connector Poor contact of coupling connector

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0031 HO2S HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 1)»(ref-325332-S12043216872009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0032 HO2S HEATER CONTROL CIRCUIT HIGH (BANK 1 SENSOR 1)»(ref-325332-S40314110762009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0037 HO2S HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 2)»(ref-325332-S18906872532009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 9

Scheme 9: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK POWER SUPPLY TO REAR OXYGEN SENSOR . Turn the ignition switch to OFF. Disconnect the connector from the rear oxygen sensor. Turn the ignition switch to ON. Measure the voltage between rear oxygen sensor connector and engine ground. Connector & terminal (E22) No. 2 (+) - Engine ground (-)	Is the voltage 10 V or more?	Go to step 2 .	Repair the power supply line. Or replace the main relay. NOTE: In this case, repair the following item: Open circuit in harness between A/F, oxygen sensor relay connector and rear oxygen sensor connector Poor contact of A/F, oxygen sensor relay connector Poor contact of coupling connector
2 CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR . Turn the ignition switch to OFF. Disconnect the connectors from the ECM. Measure the resistance between ECM and oxygen sensor connector. Connector & terminal (B136) No. 4 - (E22) No. 1	Is the resistance less than 1 ohms?	Go to step 3 .	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between ECM and rear oxygen sensor connector Poor contact of coupling connector
3 CHECK GROUND CIRCUIT FOR ECM . Measure the resistance of harness between ECM and chassis ground. Connector & terminal (B134) No. 5 - Chassis ground: (B137) No. 1 - Chassis ground: (B137) No. 2 - Chassis ground: (B137) No. 3 - Chassis ground: (B137) No. 7 - Chassis ground	Is the resistance less than 5 ohms?	Go to step 4 .	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit of harness between ECM and engine ground Poor contact of coupling connector
4 CHECK REAR OXYGEN SENSOR . Measure the resistance between rear oxygen sensor terminals. Terminals No. 2 - No. 1	Is the resistance between 5 - 7 ohms?	Repair poor contact of the ECM connector.	Replace the rear oxygen sensor. Refer to REAR OXYGEN SENSOR .

NOTE
In this case, repair the following item: Open circuit in harness between A/F, oxygen sensor relay connector and rear oxygen sensor connector Poor contact of A/F, oxygen sensor relay connector Poor contact of coupling connector

NOTE
In this case, repair the following item: Open circuit in harness between ECM and rear oxygen sensor connector Poor contact of coupling connector

NOTE
In this case, repair the following item: Open circuit of harness between ECM and engine ground Poor contact of coupling connector

DIAGNOSIS PROCEDURE CHART

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0038 HO2S HEATER CONTROL CIRCUIT HIGH (BANK 1 SENSOR 2)»(ref-325332-S22253242972009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0068 MAP/MAF - THROTTLE POSITION CORRELATION»(ref-325332-S40863659592009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 10

Scheme 10: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK AIR INTAKE SYSTEM .	Are there holes, loose bolts or disconnection of hose on air intake system?	Repair the air intake system.	Go to step 2 .
2 CHECK MANIFOLD ABSOLUTE PRESSURE SENSOR . Start the engine and warm up engine until coolant temperature is higher than 75°C (167°F). For AT models, set the select lever to "P" range or "N" range, and for MT models, place the shift lever in the neutral position. Turn the A/C switch to OFF. Turn all the accessory switches to OFF. Read the data of intake manifold pressure sensor signal using Subaru Select Monitor or general scan tool. NOTE: Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the General Scan Tool Instruction Manual.	Is the measured value 73.3 - 106.6 kPa (550 - 800 mmHg, 21.65 - 31.50 inHg) when the ignition is turned ON, and 20.0 - 46.7 kPa (150 - 350 mmHg, 5.91 - 13.78 inHg) during idling?	Go to step 3 .	Replace the manifold absolute pressure sensor. Refer to MANIFOLD ABSOLUTE PRESSURE SENSOR .
3 CHECK THROTTLE OPENING ANGLE . Read the data of throttle position signal using Subaru Select Monitor or general scan tool. NOTE: Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the General Scan Tool Instruction Manual.	Is the measured value less than 5% when throttle is fully closed?	Go to step 4 .	Replace the electronic throttle control. Refer to THROTTLE BODY .
4 CHECK THROTTLE OPENING ANGLE .	Is the measured value 85% or more when throttle is fully open?	Replace the manifold absolute pressure sensor. Refer to MANIFOLD ABSOLUTE PRESSURE SENSOR .	Replace the electronic throttle control. Refer to THROTTLE BODY .

NOTE
Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the General Scan Tool Instruction Manual.

NOTE
Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the General Scan Tool Instruction Manual.

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0076 INTAKE VALVE CONTROL SOLENOID CIRCUIT LOW (BANK 1)»(ref-325332-S17094034342009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 11

Scheme 11: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN ECM AND OIL SWITCHING SOLENOID VALVE . Turn the ignition switch to OFF. Disconnect the connectors from the ECM and oil switching solenoid valve. Measure the resistance of harness between ECM and oil switching solenoid valve. Connector & terminal (B137) No. 25 - (E69) No. 1: (B137) No. 24 - (E69) No. 2	Is the resistance less than 1 ohms?	Go to step 2 .	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit of harness between ECM and oil switching solenoid valve connector Poor contact of coupling connector
2 CHECK HARNESS BETWEEN ECM AND OIL SWITCHING SOLENOID VALVE . Measure the resistance between ECM and chassis ground. Connector & terminal (B137) No. 25 - Chassis ground: (B137) No. 24 - Chassis ground	Is the resistance 1 Mohms or more?	Go to step 3 .	Repair the ground short circuit of harness between ECM and oil switching solenoid valve connector.
3 CHECK OIL SWITCHING SOLENOID VALVE . Measure the resistance between oil switching solenoid valve terminals. Terminals No. 1 - No. 2	Is the resistance between 6 - 12 ohms?	Repair the poor contact of ECM and oil switching solenoid valve connector.	Replace the oil switching solenoid valve. Refer to OIL SWITCHING SOLENOID VALVE .

NOTE
In this case, repair the following item: Open circuit of harness between ECM and oil switching solenoid valve connector Poor contact of coupling connector

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0077 INTAKE VALVE CONTROL SOLENOID CIRCUIT HIGH (BANK 1)»(ref-325332-S15501116202009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0082 INTAKE VALVE CONTROL SOLENOID CIRCUIT LOW (BANK 2)»(ref-325332-S30978099522009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 12

Scheme 12: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN ECM AND OIL SWITCHING SOLENOID VALVE . Turn the ignition switch to OFF. Disconnect the connectors from the ECM and oil switching solenoid valve. Measure the resistance between ECM and oil switching solenoid valve. Connector & terminal (B137) No. 31 - (E70) No. 1: (B137) No. 30 - (E70) No. 2	Is the resistance less than 1 ohms?	Go to step 2 .	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit of harness between ECM and oil switching solenoid valve connector Poor contact of coupling connector
2 CHECK HARNESS BETWEEN ECM AND OIL SWITCHING SOLENOID VALVE . Measure the resistance between ECM and chassis ground. Connector & terminal (B137) No. 31 - Chassis ground: (B137) No. 30 - Chassis ground	Is the resistance 1 Mohms or more?	Go to step 3 .	Repair the ground short circuit of harness between ECM and oil switching solenoid valve connector.
3 CHECK OIL SWITCHING SOLENOID VALVE . Measure the resistance between oil switching solenoid valve terminals. Terminals No. 1 - No. 2	Is the resistance between 6 - 12 ohms?	Repair the poor contact of ECM and oil switching solenoid valve connector.	Replace the oil switching solenoid valve. Refer to OIL SWITCHING SOLENOID VALVE .

NOTE
In this case, repair the following item: Open circuit of harness between ECM and oil switching solenoid valve connector Poor contact of coupling connector

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0083 INTAKE VALVE CONTROL SOLENOID CIRCUIT HIGH (BANK 2)»(ref-325332-S23103687592009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0101 MASS OR VOLUME AIR FLOW CIRCUIT RANGE/PERFORMANCE»(ref-325332-S17136872792009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Engine stalls.
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 13

Scheme 13: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK FOR ANY OTHER DTC ON DISPLAY .	Is any other DTC displayed?	Check the appropriate DTC using the "List of Diagnostic Trouble Code (DTC)". Refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .	Replace the mass air flow and intake air temperature sensor. Refer to MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR .

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0102 MASS OR VOLUME AIR FLOW CIRCUIT LOW INPUT»(ref-325332-S28628029972009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Engine stalls.
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0103 MASS OR VOLUME AIR FLOW CIRCUIT HIGH INPUT»(ref-325332-S06295373932009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Engine stalls.
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0107 MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRESSURE CIRCUIT LOW INPUT»(ref-325332-S34472841832009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0108 MANIFOLD ABSOLUTE PRESSURE/BAROMETRIC PRESSURE CIRCUIT HIGH INPUT»(ref-325332-S42713241422009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0111 INTAKE AIR TEMPERATURE SENSOR 1 CIRCUIT RANGE/PERFORMANCE»(ref-325332-S17336510752009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0112 INTAKE AIR TEMPERATURE SENSOR 1 CIRCUIT LOW»(ref-325332-S35051061332009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0113 INTAKE AIR TEMPERATURE SENSOR 1 CIRCUIT HIGH»(ref-325332-S38277432252009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0117 ENGINE COOLANT TEMPERATURE CIRCUIT LOW»(ref-325332-S19217313552009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Hard to start
Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 14

Scheme 14: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK CURRENT DATA . Start the engine. Read the data of engine coolant temperature sensor signal using Subaru Select Monitor or general scan tool. NOTE: Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the general scan tool operation manual.	Is the engine coolant temperature 150°C (302°F) or higher?	Go to step 2 .	Even if the malfunction indicator light illuminates, the circuit has returned to a normal condition at this time. Reproduce the fault condition, and reperform the check. NOTE: In this case, there may be a temporary connector contact failure.
2 CHECK HARNESS BETWEEN ECM AND ENGINE COOLANT TEMPERATURE SENSOR CONNECTOR . Turn the ignition switch to OFF. Disconnect the connectors from the ECM and engine coolant temperature sensor. Measure the resistance between ECM and chassis ground. Connector & terminal (B134) No. 34 - Chassis ground	Is the resistance 1 Mohms or more?	Replace the engine coolant temperature sensor. Refer to ENGINE COOLANT TEMPERATURE SENSOR .	Repair short circuit in harness to ground between ECM and engine coolant temperature sensor connector.

NOTE
Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the general scan tool operation manual.

NOTE
In this case, there may be a temporary connector contact failure.

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0118 ENGINE COOLANT TEMPERATURE CIRCUIT HIGH»(ref-325332-S14402354042009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Hard to start
Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0122 THROTTLE/PEDAL POSITION SENSOR/SWITCH "A" CIRCUIT LOW»(ref-325332-S02106881632009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Engine stalls.
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 15

Scheme 15: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL . Turn the ignition switch to OFF. Disconnect the connectors from ECM and electronic throttle control. Measure the resistance between ECM and chassis ground. Connector & terminal (B134) No. 19 - Chassis ground: (B134) No. 18 - Chassis ground: (B134) No. 18 - (B136) No. 6	Is the resistance 1 Mohms or more?	Go to step 2 .	Repair the ground short circuit of harness between ECM and electronic throttle control connector.
2 CHECK SHORT CIRCUIT INSIDE THE ECM . Connect the connector to ECM. Measure the resistance between electronic throttle control connector and engine ground. Connector & terminal (E57) No. 6 - Engine ground	Is the resistance 1 Mohms or more?	Replace the electronic throttle control. Refer to THROTTLE BODY .	Repair the ground short circuit of harness between ECM and electronic throttle control connector. Replace the ECM if defective. Refer to ENGINE CONTROL MODULE (ECM) .

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0123 THROTTLE/PEDAL POSITION SENSOR/SWITCH "A" CIRCUIT HIGH»(ref-325332-S25629099892009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Engine stalls.
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0125 INSUFFICIENT COOLANT TEMPERATURE FOR CLOSED LOOP FUEL CONTROL»(ref-325332-S20979864182009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Engine does not return to idle.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Step	Check	Yes	No
1 CHECK TIRE SIZE .	Is the tire size as specified? and the same size as other three wheels?	Go to step 2 .	Replace the tire.
2 CHECK ENGINE COOLANT . Check the following items: Amount of engine coolant Engine coolant freeze Contamination of engine coolant	Is the engine coolant normal?	Go to step 3 .	Fill or replace the engine coolant. Refer to REPLACEMENT , Engine Coolant.
3 CHECK THERMOSTAT .	Does the thermostat remain opened?	Replace the thermostat. Refer to THERMOSTAT .	Replace the engine coolant temperature sensor. Refer to ENGINE COOLANT TEMPERATURE SENSOR .

DIAGNOSIS PROCEDURE CHART

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0126 INSUFFICIENT ENGINE COOLANT TEMPERATURE FOR STABLE OPERATION»(ref-325332-S16702866482009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Hard to start
Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0128 COOLANT THERMOSTAT (ENGINE COOLANT TEMPERATURE BELOW THERMOSTAT REGULATING TEMPERATURE)»(ref-325332-S04098267312009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Thermostat remains open.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Step	Check	Yes	No
1 CHECK ENGINE COOLANT .	Are the coolant level and mixture ratio of engine coolant to anti-freeze solution correct?	Go to step 2 .	Replace the engine coolant. Refer to REPLACEMENT , Engine Coolant.
2 CHECK RADIATOR FAN . Start the engine. Check the radiator fan operation.	Does the radiator fan continuously rotate for 3 minutes or more during idling?	Repair radiator fan circuit. Refer to RADIATOR MAIN FAN AND FAN MOTOR . and Refer to RADIATOR SUB FAN AND FAN MOTOR .	Replace the thermostat. Refer to THERMOSTAT .

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0131 O2 SENSOR CIRCUIT LOW VOLTAGE (BANK 1 SENSOR 1)»(ref-325332-S41259252522009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0132 O2 SENSOR CIRCUIT HIGH VOLTAGE (BANK 1 SENSOR 1)»(ref-325332-S01881499552009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0133 O2 SENSOR CIRCUIT SLOW RESPONSE (BANK 1 SENSOR 1)»(ref-325332-S00000381382009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0134 O2 SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 1 SENSOR 1)»(ref-325332-S41919225192009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0137 O2 SENSOR CIRCUIT LOW VOLTAGE (BANK 1 SENSOR 2)»(ref-325332-S04441442432009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0138 O2 SENSOR CIRCUIT HIGH VOLTAGE (BANK 1 SENSOR 2)»(ref-325332-S30124971102009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0139 O2 SENSOR CIRCUIT SLOW RESPONSE (BANK 1 SENSOR 2)»(ref-325332-S37758120912009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0140 O2 SENSOR CIRCUIT NO ACTIVITY DETECTED (BANK 1 SENSOR 2)»(ref-325332-S31593732892009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0172 SYSTEM TOO RICH (BANK 1)»(ref-325332-S41460024902009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Engine stalls.
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Step	Check	Yes	No
1 CHECK EXHAUST SYSTEM .	Are there holes or loose bolts on exhaust system?	Repair the exhaust system.	Go to step 2 .
2 CHECK AIR INTAKE SYSTEM .	Are there holes, loose bolts or disconnection of hose on air intake system?	Repair the air intake system.	Go to step 3 .
3 CHECK FUEL PRESSURE . WARNING: Place "NO OPEN FLAMES" signs near the working area. CAUTION: Be careful not to spill fuel. Measure the fuel pressure. Refer to INSPECTION , Fuel Pressure. CAUTION: Release fuel pressure before removing the fuel pressure gauge.	Is the measured value 333.4 - 360.5 kPa (3.4 - 3.7 kg/cm 2 , 48.4 - 52 psi)?	Go to step 4 .	Repair the following item. Fuel pressure is too high: Clogged fuel line or bent hose Fuel pressure is too low: Improper fuel pump discharge Clogged fuel line
4 CHECK ENGINE COOLANT TEMPERATURE SENSOR . Start the engine and warm up completely. Read the data of engine coolant temperature sensor signal using Subaru Select Monitor or general scan tool. NOTE: Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the general scan tool operation manual.	Is the engine coolant temperature 75°C (167°F) or higher?	Go to step 5 .	Replace the engine coolant temperature sensor. Refer to ENGINE COOLANT TEMPERATURE SENSOR .
5 CHECK MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR . Start the engine and warm up engine until coolant temperature is higher than 75°C (167°F). For AT models, set the select lever to "P" range or "N" range, and for MT models, place the shift lever in the neutral position. Turn the A/C switch to OFF. Turn all the accessory switches to OFF. Read the data of mass airflow and intake air temperature sensor signal using Subaru Select Monitor or general scan tool. NOTE: Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the general scan tool operation manual.	Is the measured value 2.0 - 5.0 g/s (0.26 - 0.66 lb/m)?	Go to step 6 .	Replace the mass air flow and intake air temperature sensor. Refer to MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR .
6 CHECK MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR . Start the engine and warm up engine until coolant temperature is higher than 75°C (167°F). For AT models, set the select lever to "P" range or "N" range, and for MT models, place the shift lever in the neutral position. Turn the A/C switch to OFF. Turn all the accessory switches to OFF. Open the front hood. Measure the ambient temperature. Read the data of mass airflow and intake air temperature sensor signal using Subaru Select Monitor or general scan tool. NOTE: Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the general scan tool operation manual.	Subtract ambient temperature from intake air temperature. Is the obtained value -10 - 50°C (-18 - 90°F)?	Repair the poor contact of the ECM connector.	Check the mass air flow and intake air temperature sensor. Refer to MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR .

WARNING
Place "NO OPEN FLAMES" signs near the working area.

CAUTION
Be careful not to spill fuel.

CAUTION
Release fuel pressure before removing the fuel pressure gauge.

NOTE
Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the general scan tool operation manual.

NOTE
Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the general scan tool operation manual.

NOTE
Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the general scan tool operation manual.

DIAGNOSIS PROCEDURE CHART

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0181 FUEL TEMPERATURE SENSOR "A" CIRCUIT RANGE/PERFORMANCE»(ref-325332-S00720090512009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 16

Scheme 16: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK FOR ANY OTHER DTC ON DISPLAY .	Is any other DTC displayed?	Check the appropriate DTC using the "List of Diagnostic Trouble Code (DTC)". Refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .	Replace the fuel temperature sensor. Refer to FUEL TEMPERATURE SENSOR .

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0182 FUEL TEMPERATURE SENSOR "A" CIRCUIT LOW INPUT»(ref-325332-S35088287642009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0183 FUEL TEMPERATURE SENSOR "A" CIRCUIT HIGH INPUT»(ref-325332-S26787461652009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0196 ENGINE OIL TEMPERATURE SENSOR CIRCUIT RANGE/PERFORMANCE»(ref-325332-S03074336972009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Hard to start
Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 17

Scheme 17: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK FOR ANY OTHER DTC ON DISPLAY .	Is any other DTC displayed?	Check the appropriate DTC using the "List of Diagnostic Trouble Code (DTC)". Refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .	Replace the oil temperature sensor. Refer to OIL TEMPERATURE SENSOR .

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0197 ENGINE OIL TEMPERATURE SENSOR LOW»(ref-325332-S41935848662009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Hard to start
Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0198 ENGINE OIL TEMPERATURE SENSOR HIGH»(ref-325332-S34614516902009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Hard to start
Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0222 THROTTLE/PEDAL POSITION SENSOR/SWITCH "B" CIRCUIT LOW»(ref-325332-S33420167392009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance
Engine stalls.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0223 THROTTLE/PEDAL POSITION SENSOR/SWITCH "B" CIRCUIT HIGH»(ref-325332-S03580046092009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance
Engine stalls.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
Immediately at fault recognition (A misfire which could damage catalyst occurs).
GENERAL DESCRIPTION Refer to «DTC P0304 CYLINDER 4 MISFIRE DETECTED»(ref-325332-S39026319372009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Engine stalls.
Improper idling
Rough driving

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0327 KNOCK SENSOR 1 CIRCUIT LOW (BANK 1 OR SINGLE SENSOR)»(ref-325332-S20149612212009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Poor driving performance
Knocking occurs.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 18

Scheme 18: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN ECM AND KNOCK SENSOR . Turn the ignition switch to OFF. Disconnect the connectors from the ECM. Measure the resistance between ECM connectors. Connector & terminal (B134) No. 15 - (B134) No. 29	Is the resistance 600 kohms or more?	Go to step 2 .	Repair poor contact of the ECM connector.
2 CHECK KNOCK SENSOR . Disconnect the connector from knock sensor. Measure the resistance between knock sensor terminals. Terminals No. 1 - No. 2	Is the resistance 600 kohms or more?	Replace the knock sensor. Refer to KNOCK SENSOR .	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between ECM and knock sensor connector Poor contact of the knock sensor connector Poor contact of coupling connector

NOTE
In this case, repair the following item: Open circuit in harness between ECM and knock sensor connector Poor contact of the knock sensor connector Poor contact of coupling connector

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0328 KNOCK SENSOR 1 CIRCUIT HIGH (BANK 1 OR SINGLE SENSOR)»(ref-325332-S03572902352009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Poor driving performance
Knocking occurs.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0335 CRANKSHAFT POSITION SENSOR "A" CIRCUIT»(ref-325332-S34118970582009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Engine stalls.
Failure of engine to start

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 19

Scheme 19: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK INSTALLATION CONDITION OF CRANKSHAFT POSITION SENSOR .	Is the crankshaft position sensor installation bolt tightened securely?	Go to step 2 .	Tighten the crankshaft position sensor installation bolt securely.
2 CHECK CRANKSHAFT POSITION SENSOR . Turn the ignition switch to OFF. Remove the crankshaft position sensor. Measure the resistance between terminals of crankshaft position sensor. Terminals No. 1 - No. 2	Is the resistance between 1 and 4 kohms?	Go to step 3 .	Replace the crankshaft position sensor. Refer to CRANKSHAFT POSITION SENSOR .
3 CHECK HARNESS BETWEEN ECM AND CRANK SHAFT POSITION SENSOR . Disconnect the connectors from the ECM. Measure the resistance of harness between the ECM and crankshaft position sensor connector. Connector & terminal (B134) No. 13 - (E10) No. 1: (B134) No. 14 - (E10) No. 2	Is the resistance less than 1 ohms?	Repair the poor contact of the ECM and crankshaft position sensor connector.	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit of harness between ECM and crankshaft position sensor connector Poor contact of coupling connector

NOTE
In this case, repair the following item: Open circuit of harness between ECM and crankshaft position sensor connector Poor contact of coupling connector

DIAGNOSIS PROCEDURE CHART

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0336 CRANKSHAFT POSITION SENSOR "A" CIRCUIT RANGE/PERFORMANCE»(ref-325332-S37439206272009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Engine stalls.
Failure of engine to start

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0340 CAMSHAFT POSITION SENSOR "A" CIRCUIT (BANK 1 OR SINGLE SENSOR)»(ref-325332-S35637542352009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Engine stalls.
Failure of engine to start

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 20

Scheme 20: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN ECM AND CAMSHAFT POSITION SENSOR . Turn the ignition switch to OFF. Disconnect the connectors from the ECM and camshaft position sensor. Measure the resistance of harness between the ECM and camshaft position sensor connector. Connector & terminal (B134) No. 12 - (E15) No. 1: (B134) No. 22 - (E15) No. 2	Is the resistance less than 1 ohms?	Go to step 2 .	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between the ECM and camshaft position sensor connector Poor contact of coupling connector
2 CHECK HARNESS BETWEEN ECM AND CAMSHAFT POSITION SENSOR . Measure the resistance between camshaft position sensor connector and engine ground. Connector & terminal (E15) No. 1 - Engine ground	Is the resistance 1 Mohms or more?	Go to step 3 .	Repair the short circuit to ground of harness between the ECM and camshaft position sensor. NOTE: The harness between both connectors are shielded. Remove the shield and repair the ground short circuit of the harness circuit.
3 CHECK INSTALLATION CONDITION OF CAMSHAFT POSITION SENSOR .	Is the camshaft position sensor installation bolt tightened securely?	Go to step 4 .	Tighten the camshaft position sensor installation bolt securely.
4 CHECK CAMSHAFT POSITION SENSOR . Remove the camshaft position sensor. Measure the resistance between terminals of camshaft position sensor. Terminals No. 1 - No. 2	Is the resistance between 1 and 4 kohms?	Repair the poor contact of the ECM or camshaft position sensor connector.	Replace the camshaft position sensor. Refer to CAMSHAFT POSITION SENSOR .

NOTE
In this case, repair the following item: Open circuit in harness between the ECM and camshaft position sensor connector Poor contact of coupling connector

NOTE
The harness between both connectors are shielded. Remove the shield and repair the ground short circuit of the harness circuit.

DIAGNOSIS PROCEDURE CHART

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0341 CAMSHAFT POSITION SENSOR "A" CIRCUIT RANGE/PERFORMANCE (BANK 1 OR SINGLE SENSOR)»(ref-325332-S18470524842009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Engine stalls.
Failure of engine to start

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0400 EXHAUST GAS RECIRCULATION FLOW»(ref-325332-S19889084102009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Movement performance problem when engine is low speed.
Improper idling
Movement performance problem

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 21

Scheme 21: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK CURRENT DATA . Start the engine. Read data of intake manifold absolute pressure signal using Subaru Select Monitor or general scan tool. NOTE: Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the general scan tool operation manual.	Is the measured value 53.3 kPa (400 mmHg, 15.75 inHg) or more?	Make sure that the EGR valve, manifold absolute pressure sensor and throttle body are installed securely.	Go to step 2 .
2 CHECK EGR SOLENOID VALVE . Remove the EGR valve.	Are there holes, plugged piping or foreign objects caught in the EGR system?	Repair the EGR system.	Replace the EGR valve. Refer to EGR VALVE .

NOTE
Subaru Select Monitor For detailed operation procedures, refer to "READ CURRENT DATA FOR ENGINE". Refer to SUBARU SELECT MONITOR . General scan tool For detailed operation procedures, refer to the general scan tool operation manual.

DIAGNOSIS PROCEDURE CHART

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD (BANK 1)»(ref-325332-S13970952672009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Engine stalls.
Idle mixture is out of specifications.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0442 EVAPORATIVE EMISSION CONTROL SYSTEM LEAK DETECTED (SMALL LEAK)»(ref-325332-S15347890632009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Fuel odor
There is a hole of more than 1.0 mm (0.04 in) dia. in evaporation system or fuel tank.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 22

Scheme 22: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK FUEL FILLER CAP . Turn the ignition switch to OFF. Check the fuel filler cap. NOTE: The DTC is stored in memory if fuel filler cap is or was loose or if the cap chain has caught while tightening.	Is the fuel filler cap tightened securely?	Go to step 2 .	Tighten fuel filler cap securely.
2 CHECK FUEL FILLER CAP .	Is the fuel filler cap genuine?	Go to step 3 .	Replace with a genuine fuel filler cap.
3 CHECK FUEL FILLER PIPE GASKET .	Is there any damage to the seal between fuel filler cap and fuel filler pipe?	Repair or replace the fuel filler cap and fuel filler pipe. Refer to FUEL FILLER PIPE .	Go to step 4 .
4 CHECK DRAIN VALVE . Connect the delivery (test) mode connector. Turn the ignition switch to ON. Operate the drain valve using the Subaru Select Monitor. NOTE: Drain valve operation can be executed using Subaru Select Monitor. Regarding the procedures, refer to "Compulsory Valve Operation Check Mode". Refer to COMPULSORY VALVE OPERATION CHECK MODE .	Does the drain valve operate?	Go to step 5 .	Replace the drain valve. Refer to DRAIN VALVE .
5 CHECK PURGE CONTROL SOLENOID VALVE . Operate the purge control solenoid valve using the Subaru Select Monitor. NOTE: Purge control solenoid valve operation can be executed using Subaru Select Monitor. Regarding the procedures, refer to "Compulsory Valve Operation Check Mode". Refer to COMPULSORY VALVE OPERATION CHECK MODE .	Does the purge control solenoid valve operate?	Go to step 6 .	Replace the purge control solenoid valve. Refer to PURGE CONTROL SOLENOID VALVE .
6 CHECK PRESSURE CONTROL SOLENOID VALVE . Operate the pressure control solenoid valve using the Subaru Select Monitor. NOTE: The pressure control solenoid valve operation can be executed using the Subaru Select Monitor. Regarding the procedures, refer to "Compulsory Valve Operation Check Mode". Refer to COMPULSORY VALVE OPERATION CHECK MODE .	Does the pressure control solenoid valve operate?	Go to step 7 .	Replace the pressure control solenoid valve. Refer to PRESSURE CONTROL SOLENOID VALVE .
7 CHECK EVAPORATIVE EMISSION CONTROL SYSTEM LINE . Turn the ignition switch to OFF. Disconnect the delivery (test) mode connector.	Is there any hole of more than 1.0 mm (0.04 in) dia. on evaporation line?	Repair or replace the evaporation line. Refer to FUEL DELIVERY AND EVAPORATION LINES .	Go to step 8 .
8 CHECK CANISTER .	Is the canister damaged or is there a hole of more than 1.0 mm (0.04 in) dia. in it?	Repair or replace the canister. Refer to CANISTER .	Go to step 9 .
9 CHECK FUEL TANK . Remove the fuel tank. Refer to FUEL TANK .	Is the fuel tank damaged or is there any hole of more than 1.0 mm (0.04 in) dia. in it?	Repair or replace the fuel tank. Refer to FUEL TANK .	Go to step 10 .
10 CHECK ANY OTHER MECHANICAL TROUBLE IN EVAPORATIVE EMISSION CONTROL SYSTEM .	Is there any hole of more than 1.0 mm (0.04 in) dia., crack, clogging, or disconnections, bend, misconnection of hoses or pipes in evaporative emission control system?	Repair or replace the hoses or pipes.	Repair the poor contact of the ECM connector.

NOTE
The DTC is stored in memory if fuel filler cap is or was loose or if the cap chain has caught while tightening.

NOTE
Drain valve operation can be executed using Subaru Select Monitor. Regarding the procedures, refer to "Compulsory Valve Operation Check Mode". Refer to COMPULSORY VALVE OPERATION CHECK MODE .

NOTE
Purge control solenoid valve operation can be executed using Subaru Select Monitor. Regarding the procedures, refer to "Compulsory Valve Operation Check Mode". Refer to COMPULSORY VALVE OPERATION CHECK MODE .

NOTE
The pressure control solenoid valve operation can be executed using the Subaru Select Monitor. Regarding the procedures, refer to "Compulsory Valve Operation Check Mode". Refer to COMPULSORY VALVE OPERATION CHECK MODE .

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0447 EVAPORATIVE EMISSION CONTROL SYSTEM VENT CONTROL CIRCUIT OPEN»(ref-325332-S01331305252009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0448 EVAPORATIVE EMISSION CONTROL SYSTEM VENT CONTROL CIRCUIT SHORTED»(ref-325332-S02174802682009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0451 EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR»(ref-325332-S35969452472009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 23

Scheme 23: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK FUEL FILLER CAP . Turn the ignition switch to OFF. Open the fuel flap.	Is the fuel filler cap tightened securely?	Go to step 2 .	Tighten fuel filler cap securely.
2 CHECK PRESSURE VACUUM LINE . NOTE: Check the following items. Disconnection, leakage and clogging of the vacuum hoses and pipes between fuel tank pressure sensor and fuel tank Disconnection, leakage and clogging of air ventilation hoses and pipes between fuel filler pipe and fuel tank	Is there any fault in pressure/vacuum line?	Repair or replace the hoses and pipes.	Replace the fuel tank pressure sensor. Refer to FUEL TANK PRESSURE SENSOR .

NOTE
Check the following items. Disconnection, leakage and clogging of the vacuum hoses and pipes between fuel tank pressure sensor and fuel tank Disconnection, leakage and clogging of air ventilation hoses and pipes between fuel filler pipe and fuel tank

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0452 EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR LOW INPUT»(ref-325332-S15624583102009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0453 EVAPORATIVE EMISSION CONTROL SYSTEM PRESSURE SENSOR HIGH INPUT»(ref-325332-S06419642972009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0456 EVAPORATIVE EMISSION CONTROL SYSTEM LEAK DETECTED (VERY SMALL LEAK)»(ref-325332-S05153320152009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Fuel odor
There is a hole of more than 0.5 mm (0.020 in) dia. in evaporation system or fuel tank.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0457 EVAPORATIVE EMISSION CONTROL SYSTEM LEAK DETECTED (FUEL CAP LOOSE/OFF)»(ref-325332-S25939875912009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Fuel odor
Fuel filler cap loose or lost

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0458 EVAPORATIVE EMISSION SYSTEM PURGE CONTROL VALVE CIRCUIT LOW»(ref-325332-S29699553582009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0459 EVAPORATIVE EMISSION SYSTEM PURGE CONTROL VALVE CIRCUIT HIGH»(ref-325332-S20634990402009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 24

Scheme 24: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN ECM AND PURGE CONTROL SOLENOID VALVE . Turn the ignition switch to OFF. Disconnect the connectors from ECM and purge control solenoid valve. Turn the ignition switch to ON. Measure the voltage between ECM and chassis ground. Connector & terminal (B137) No. 29 (+) - Chassis ground (-)	Is the voltage 10 V or more?	Repair the short circuit to power in the harness between the ECM and purge control solenoid valve connector.	Go to step 2 .
2 CHECK PURGE CONTROL SOLENOID VALVE . Turn the ignition switch to OFF. Measure the resistance between purge control solenoid valve terminals. Terminals No. 1 - No. 2	Is the resistance less than 1 ohms?	Replace the purge control solenoid valve. Refer to PURGE CONTROL SOLENOID VALVE .	Repair the poor contact of the ECM connector.

DIAGNOSIS PROCEDURE CHART

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0461 FUEL LEVEL SENSOR "A" CIRCUIT RANGE/PERFORMANCE»(ref-325332-S21985344812009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Step	Check	Yes	No
1 CHECK FOR ANY OTHER DTC ON DISPLAY .	Is any other DTC displayed?	Check the appropriate DTC using the "List of Diagnostic Trouble Code (DTC)". Refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .	Replace the fuel level sensor and fuel sub level sensor. Refer to FUEL LEVEL SENSOR . Refer to FUEL SUB LEVEL SENSOR .

DIAGNOSIS PROCEDURE CHART

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0463 FUEL LEVEL SENSOR "A" CIRCUIT HIGH»(ref-325332-S05551466172009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Step	Check	Yes	No
1 CHECK FOR ANY OTHER DTC ON DISPLAY .	Is DTC P0462 or P0463 displayed on the Subaru Select Monitor?	Check the combination meter. Refer to CHECK FUEL LEVEL SENSOR , INSPECTION, Combination Meter System.	Even if the malfunction indicator light illuminates, the circuit has returned to a normal condition at this time. Reproduce the fault condition, and reperform the check. NOTE: In this case, there may be a temporary connector contact failure.

NOTE
In this case, there may be a temporary connector contact failure.

DIAGNOSIS PROCEDURE CHART

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0464 FUEL LEVEL SENSOR CIRCUIT INTERMITTENT»(ref-325332-S01503529162009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Step	Check	Yes	No
1 CHECK FOR ANY OTHER DTC ON DISPLAY .	Is DTC P0464 displayed on the display?	Check the combination meter. Refer to CHECK FUEL LEVEL SENSOR , INSPECTION, Combination Meter System.	Even if the malfunction indicator light illuminates, the circuit has returned to a normal condition at this time. Reproduce the fault condition, and reperform the check. NOTE: In this case, there may be a temporary connector contact failure.

NOTE
In this case, there may be a temporary connector contact failure.

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0500 VEHICLE SPEED SENSOR "A"»(ref-325332-S42087306952009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Step	Check	Yes	No
1 CHECK DTC OF VDC . Check DTC of VDC.	Is DTC of VDC displayed?	Perform the diagnosis according to DTC. Refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .	Repair poor contact of the ECM connector.

DIAGNOSIS PROCEDURE CHART

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0506 IDLE AIR CONTROL SYSTEM RPM LOWER THAN EXPECTED»(ref-325332-S11314711802009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Hard to start the engine.
Engine does not start.
Improper idling
Engine stalls.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0507 IDLE AIR CONTROL SYSTEM RPM HIGHER THAN EXPECTED»(ref-325332-S21941795952009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Engine keeps running at higher speed than specified idle speed.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0512 STARTER REQUEST CIRCUIT»(ref-325332-S24495266482009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Failure of engine to start

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P0604 INTERNAL CONTROL MODULE RANDOM ACCESS MEMORY (RAM) ERROR»(ref-325332-S04842734722009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Engine does not start.
Engine stalls.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Depending on the content of malfunction, adapt either of the followings. Immediately at fault recognition Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0607 THROTTLE CONTROL SYSTEM CIRCUIT RANGE/PERFORMANCE»(ref-325332-S28661482552009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 25

Scheme 25: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK INPUT VOLTAGE OF ECM . Turn the ignition switch to ON. Measure the voltage between ECM and chassis ground. Connector & terminal (B134) No. 7 (+) - Chassis ground (-): (B135) No. 2 (+) - Chassis ground (-)	Is the voltage 10 - 13 V?	Go to step 2 .	Repair the open or ground short circuit of power supply circuit.
2 CHECK INPUT VOLTAGE OF ECM . Start the engine. Measure the voltage between ECM and chassis ground. Connector & terminal (B134) No. 7 (+) - Chassis ground (-): (B135) No. 2 (+) - Chassis ground (-)	Is the voltage 13 - 15 V?	Go to step 3 .	Repair the open or ground short circuit of power supply circuit.
3 CHECK HARNESS BETWEEN ECM AND ELECTRONIC THROTTLE CONTROL . Turn the ignition switch to OFF. Disconnect the connectors from ECM and electronic throttle control. Measure the resistance of harness between ECM and electronic throttle control connector. Connector & terminal (B134) No. 19 - (E57) No. 5: (B134) No. 29 - (E57) No. 3	Is the resistance less than 1 ohms?	Go to step 4 .	Repair the open circuit of harness between ECM and electronic throttle control connector.
4 CHECK ECM GROUND HARNESS . Measure the voltage between ECM and chassis ground. Connector & terminal (B134) No. 5 (+) - Chassis ground (-): (B137) No. 1 (+) - Chassis ground (-): (B137) No. 2 (+) - Chassis ground (-): (B137) No. 3 (+) - Chassis ground (-): (B137) No. 7 (+) - Chassis ground (-)	Is the voltage less than 1 V?	Repair the poor contact of the ECM connector.	Repair the following item. Open circuit of ground circuit Retightening of engine ground terminals Poor contact in ECM connector Poor contact of coupling connector

DIAGNOSIS PROCEDURE CHART

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0851 PARK/NEUTRAL SWITCH INPUT CIRCUIT LOW (AT MODEL)»(ref-325332-S01205835242009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 26

Scheme 26: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK SELECT CABLE .	Are there any faults in the select cable?	Repair or adjust the select cable. Refer to SELECT CABLE .	Go to step 2 .
2 CHECK INPUT SIGNAL OF ECM . Turn the ignition switch to ON. Place the select lever in other than "P" range and "N" range. Measure the voltage between ECM and chassis ground. Connector & terminal (B136) No. 31 (+) - Chassis ground (-)	Is the voltage 10 V or more?	Repair the poor contact of the ECM connector.	Go to step 3 .
3 CHECK HARNESS BETWEEN ECM AND TRANSMISSION HARNESS CONNECTOR . Turn the ignition switch to OFF. Disconnect the connectors from ECM and transmission harness connector (T3). Measure the resistance between ECM and chassis ground. Connector & terminal (B136) No. 31 - Chassis ground	Is the resistance 1 Mohms or more?	Go to step 4 .	Repair the ground short circuit of harness between ECM and transmission harness connector.
4 CHECK TRANSMISSION HARNESS CONNECTOR . Disconnect the connector from inhibitor switch. Measure the resistance between the transmission harness connector and engine ground. Connector & terminal (T3) No. 12 - Engine ground	Is the resistance 1 Mohms or more?	Replace the inhibitor switch. Refer to INHIBITOR SWITCH .	Repair the ground short circuit of harness between transmission harness connector and inhibitor switch connector.

DIAGNOSIS PROCEDURE CHART

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0851 NEUTRAL SWITCH INPUT CIRCUIT LOW (MT MODEL)»(ref-325332-S07751558422009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0852 PARK/NEUTRAL SWITCH INPUT CIRCUIT HIGH (AT MODEL)»(ref-325332-S07933630712009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P0852 NEUTRAL SWITCH INPUT CIRCUIT HIGH (MT MODEL)»(ref-325332-S01797367272009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P1152 O2 SENSOR CIRCUIT RANGE/PERFORMANCE (LOW) (BANK 1 SENSOR 1)»(ref-325332-S02892506342009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P1153 O2 SENSOR CIRCUIT RANGE/PERFORMANCE (HIGH) (BANK 1 SENSOR 1)»(ref-325332-S35865625852009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P1400 FUEL TANK PRESSURE CONTROL SOLENOID VALVE CIRCUIT LOW»(ref-325332-S32188624132009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P1420 FUEL TANK PRESSURE CONTROL SOL. VALVE CIRCUIT HIGH»(ref-325332-S31473491542009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P1443 VENT CONTROL SOLENOID VALVE FUNCTION PROBLEM»(ref-325332-S31398067492009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper fuel supply

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P1491 POSITIVE CRANKCASE VENTILATION (BLOW-BY) FUNCTION PROBLEM»(ref-325332-S18102554632009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 27

Scheme 27: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK BLOW-BY HOSE . Check the blow-by hose condition.	Is there any disconnection or crack in blow-by hose?	Repair or replace the blow-by hose.	Go to step 2 .
2 CHECK HARNESS BETWEEN ECM AND PCV HOSE ASSEMBLY . Turn the ignition switch to OFF. Disconnect the connectors from the ECM and PCV hose assembly. Measure the resistance of harness between ECM and PCV hose assembly connector. Connector & terminal (B134) No. 30 - (E61) No. 2	Is the resistance less than 1 ohms?	Go to step 3 .	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between ECM and PCV hose assembly connector Poor contact of coupling connector
3 CHECK HARNESS BETWEEN ECM AND PCV HOSE ASSEMBLY . Measure the resistance between PCV hose assembly connector and chassis ground. Connector & terminal (B134) No. 30 - Chassis ground	Is the resistance 1 Mohms or more?	Go to step 4 .	Repair the short circuit to ground in harness between ECM and PCV hose assembly connector.
4 CHECK GROUND CIRCUIT OF PCV HOSE ASSEMBLY . Measure the resistance of harness between PCV hose assembly connector and engine ground. Connector & terminal (E61) No. 1 - Engine ground	Is the resistance less than 5 ohms?	Go to step 5 .	Repair the open circuit of harness between PCV hose assembly and engine ground.
5 CHECK THE PCV HOSE ASSEMBLY . Measure the resistance between the PCV hose assembly terminals. Terminals No. 1 - No. 2	Is the resistance less than 1 ohms?	Repair the poor contact in ECM and PCV hose assembly connector.	Replace the PCV hose assembly.

NOTE
In this case, repair the following item: Open circuit in harness between ECM and PCV hose assembly connector Poor contact of coupling connector

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P1492 EGR SOLENOID VALVE SIGNAL #1 CIRCUIT MALFUNCTION (LOW INPUT)»(ref-325332-S06827043392009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria. Refer to «DTC P1494 EGR SOLENOID VALVE SIGNAL #2 CIRCUIT MALFUNCTION (LOW INPUT)»(ref-325332-S18567327622009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria. Refer to «DTC P1496 EGR SOLENOID VALVE SIGNAL #3 CIRCUIT MALFUNCTION (LOW INPUT)»(ref-325332-S14958375952009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria. Refer to «DTC P1498 EGR SOLENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (LOW INPUT)»(ref-325332-S03241874272009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance
Engine breathing

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P1493 EGR SOLENOID VALVE SIGNAL #1 CIRCUIT MALFUNCTION (HIGH INPUT)»(ref-325332-S13652931242009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria. Refer to «DTC P1495 EGR SOLENOID VALVE SIGNAL #2 CIRCUIT MALFUNCTION (HIGH INPUT)»(ref-325332-S40363709992009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria. Refer to «DTC P1497 EGR SOLENOID VALVE SIGNAL #3 CIRCUIT MALFUNCTION (HIGH INPUT)»(ref-325332-S25745708972009071800000) , Diagnostic Trouble Code DTC) Detecting Criteria. Refer to «DTC P1499 EGR SOLENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION (HIGH INPUT)»(ref-325332-S13119454532009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance
Engine breathing

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P1560 BACK-UP VOLTAGE CIRCUIT MALFUNCTION»(ref-325332-S17389812272009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P1602 CONTROL MODULE PROGRAMMING ERROR»(ref-325332-S13591582692009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Engine keeps running at higher speed than specified idle speed.
Engine keeps running at a lower speed than the specified idle speed.
Engine stalls.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P2097 POST CATALYST FUEL TRIM SYSTEM TOO RICH (BANK 1)»(ref-325332-S07181295062009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P2101 THROTTLE ACTUATOR CONTROL MOTOR CIRCUIT RANGE/PERFORMANCE»(ref-325332-S22443950532009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance
Engine stalls.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P2102 THROTTLE ACTUATOR CONTROL MOTOR CIRCUIT LOW»(ref-325332-S19289109522009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance
Engine stalls.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P2103 THROTTLE ACTUATOR CONTROL MOTOR CIRCUIT HIGH»(ref-325332-S27173721832009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P2122 THROTTLE/PEDAL POSITION SENSOR/SWITCH "D" CIRCUIT LOW INPUT»(ref-325332-S20289511902009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Scheme 28

Scheme 28: WIRING DIAGRAM

Step	Check	Yes	No
1 CHECK HARNESS BETWEEN ECM AND ACCELERATOR PEDAL POSITION SENSOR . Turn the ignition switch to OFF. Disconnect the connector from the ECM and accelerator pedal position sensor. Measure the resistance between ECM and chassis ground. Connector & terminal (B135) No. 21 - Chassis ground: (B135) No. 23 - Chassis ground: (B135) No. 23 - (B136) No. 6	Is the resistance 1 Mohms or more?	Go to step 2 .	Repair the ground short of the harness between the ECM and accelerator pedal position sensor connector.
2 CHECK SHORT CIRCUIT INSIDE THE ECM . Connect the connector to ECM. Measure the resistance between accelerator pedal position sensor connector and chassis ground. Connector & terminal (B315) No. 6 - Chassis ground	Is the resistance 1 Mohms or more?	Replace the accelerator pedal. Refer to ACCELERATOR PEDAL .	Repair the short circuit to ground in harness between ECM and accelerator pedal position sensor connector. Replace the ECM if defective. Refer to ENGINE CONTROL MODULE (ECM) .

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P2123 THROTTLE/PEDAL POSITION SENSOR/SWITCH "D" CIRCUIT HIGH INPUT»(ref-325332-S21601468902009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P2127 THROTTLE/PEDAL POSITION SENSOR/SWITCH "E" CIRCUIT LOW INPUT»(ref-325332-S16225049562009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P2128 THROTTLE/PEDAL POSITION SENSOR/SWITCH "E" CIRCUIT HIGH INPUT»(ref-325332-S03212737792009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P2135 THROTTLE/PEDAL POSITION SENSOR/SWITCH "A"/"B" VOLTAGE CORRELATION»(ref-325332-S15678609082009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P2138 THROTTLE/PEDAL POSITION SENSOR/SWITCH "D"/"E" VOLTAGE CORRELATION»(ref-325332-S23479496882009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Improper idling
Poor driving performance

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Detected when two consecutive driving cycles with fault occur.
GENERAL DESCRIPTION Refer to «DTC P2227 BAROMETRIC PRESSURE CIRCUIT RANGE/PERFORMANCE»(ref-325332-S26206683352009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Step	Check	Yes	No
1 CHECK FOR ANY OTHER DTC ON DISPLAY .	Is any other DTC displayed?	Check DTC using "List of Diagnostic Trouble Code (DTC)". Refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .	Replace the ECM. Refer to ENGINE CONTROL MODULE (ECM) . NOTE: The barometric pressure sensor is built into the ECM.

NOTE
The barometric pressure sensor is built into the ECM.

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P2228 BAROMETRIC PRESSURE CIRCUIT LOW»(ref-325332-S34646355652009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Step	Check	Yes	No
1 CHECK FOR ANY OTHER DTC ON DISPLAY .	Is any other DTC displayed?	Check DTC using "List of Diagnostic Trouble Code (DTC)". Refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .	Replace the ECM. Refer to ENGINE CONTROL MODULE (ECM) . NOTE: The barometric pressure sensor is built into the ECM.

NOTE
The barometric pressure sensor is built into the ECM.

DIAGNOSIS PROCEDURE CHART

Immediately at fault recognition
GENERAL DESCRIPTION Refer to «DTC P2229 BAROMETRIC PRESSURE CIRCUIT HIGH»(ref-325332-S42477505142009071800000) , Diagnostic Trouble Code (DTC) Detecting Criteria.

CAUTION

After repair or replacement of faulty parts, perform Clear Memory Mode Refer to OPERATION , Clear Memory Mode and Inspection Mode Refer to PROCEDURE , Inspection Mode.

Step	Check	Yes	No
1 CHECK FOR ANY OTHER DTC ON DISPLAY .	Is any other DTC displayed?	Check DTC using "List of Diagnostic Trouble Code (DTC)". Refer to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .	Replace the ECM. Refer to ENGINE CONTROL MODULE (ECM) . NOTE: The barometric pressure sensor is built into the ECM.

NOTE
The barometric pressure sensor is built into the ECM.

DIAGNOSIS PROCEDURE CHART

Note. Malfunction of parts other than those listed is also possible. Refer to ENGINE TROUBLE IN GENERAL .

Symptom	Problem parts
1. Engine stalls during idling.	Manifold absolute pressure sensor Mass air flow and intake air temperature sensor Ignition parts ( (1) ) Engine coolant temperature sensor ( (2) ) Crankshaft position sensor ( (3) ) Camshaft position sensor ( (3) ) Fuel injection parts ( (4) )
2. Rough idling	Manifold absolute pressure sensor Mass air flow and intake air temperature sensor Engine coolant temperature sensor ( (2) ) Ignition parts ( (1) ) Air intake system ( (5) ) Fuel injection parts ( (4) ) Electronic throttle control Crankshaft position sensor ( (3) ) Camshaft position sensor ( (3) ) Oxygen sensor Fuel pump and fuel pump relay EGR valve
3. Engine does not return to idle.	Engine coolant temperature sensor Electronic throttle control Manifold absolute pressure sensor Mass air flow and intake air temperature sensor EGR valve
4. Poor acceleration	Manifold absolute pressure sensor Mass air flow and intake air temperature sensor Electronic throttle control Fuel injection parts ( (4) ) Fuel pump and fuel pump relay Engine coolant temperature sensor ( (2) ) Crankshaft position sensor ( (3) ) Camshaft position sensor ( (3) ) A/C switch and A/C cut relay Engine torque control signal circuit Ignition parts ( (1) ) EGR valve
5. Engine stalls, hesitates, or sputters at acceleration.	Manifold absolute pressure sensor Mass air flow and intake air temperature sensor Engine coolant temperature sensor ( (2) ) Crankshaft position sensor ( (3) ) Camshaft position sensor ( (3) ) Purge control solenoid valve Fuel injection parts ( (4) ) Electronic throttle control Fuel pump and fuel pump relay EGR valve
6. Surging	Mass air flow and intake air temperature sensor Manifold absolute pressure sensor Engine coolant temperature sensor ( (2) ) Crankshaft position sensor ( (3) ) Camshaft position sensor ( (3) ) Fuel injection parts ( (4) ) Electronic throttle control Fuel pump and fuel pump relay EGR valve
7. Spark knock	Mass air flow and intake air temperature sensor Manifold absolute pressure sensor Engine coolant temperature sensor Knock sensor Fuel injection parts ( (4) ) Fuel pump and fuel pump relay EGR valve
8. After burning in exhaust system	Mass air flow and intake air temperature sensor Manifold absolute pressure sensor Engine coolant temperature sensor ( (2) ) Fuel injection parts ( (4) ) Fuel pump and fuel pump relay
(1) Check ignition coil and ignitor assembly and spark plug. (2) Indicate the symptom occurring only in cold temperatures. (3) Ensure the secure installation. (4) Check fuel injector, fuel pressure regulator and fuel filter. (5) Inspect air leak in air intake system.

(1)	Check ignition coil and ignitor assembly and spark plug.

(2)	Indicate the symptom occurring only in cold temperatures.

(3)	Ensure the secure installation.

(4)	Check fuel injector, fuel pressure regulator and fuel filter.

(5)	Inspect air leak in air intake system.

ENGINE DIAGNOSTIC CHART

Engine Controls - Engine (Diagnostics) (H4SO): Diagnosis Subaru Forester SH

INSPECTION

MODE $01: (CURRENT POWERTRAIN DIAGNOSTIC DATA)

MODE $03 (EMISSION-RELATED POWERTRAIN DTC)

MODE $04 (CLEAR/RESET EMISSION-RELATED DIAGNOSTIC INFORMATION)

GENERAL SCAN TOOL

PREPARATION FOR THE INSPECTION MODE

Scheme 1

Scheme 2

DIAGNOSIS

TROUBLE SYMPTOM

Scheme 3

Scheme 4

Scheme 5

DTC DETECTING CONDITION

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23

Scheme 24

Scheme 25

Scheme 26

Scheme 27

Scheme 28

More articles — Engine Controls - Engine (Diagnostics) (H4SO)

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