HVAC System (Auto AC) (Diagnostics): Other — Subaru Outback BR (2009-2012)

PROCEDURE

Step	Check	Yes	No
1 START INSPECTIONS. Perform the pre-inspection. Ref. to INSPECTION , General Description. Perform the self-diagnosis. Ref. to OPERATION , Diagnostic Chart for Self-Diagnosis.	Does the self-diagnosis operate?	Go to step 2 .	Ref. to A/C OR SELF-DIAGNOSIS SYSTEMS DO NOT OPERATE , Diagnostics for A/C System Malfunction.
2 CHECK DTC. Read the DTC using Subaru Select Monitor. Ref. to OPERATION , Read Diagnostic Trouble Code (DTC). NOTE: When freeze frame data is displayed with DTC, record all the data.	Is DTC displayed?	Perform the diagnosis according to DTC. Ref. to LIST , List of Diagnostic Trouble Code (DTC).	Go to step 3 .
3 CHECK COMPARTMENT TEMPERATURE. Turn the A/C switch to ON. Turn the temperature control switch at maximum cool position. Check the compartment temperature change.	Does the compartment temperature change?	Go to step 4 .	Ref. to COMPARTMENT TEMPERATURE DOES NOT CHANGE, OR A/C SYSTEM DOES NOT RESPOND PROMPTLY , Diagnostics for A/C System Malfunction.
4 CHECK A/C SYSTEM RESPONSE. Change the temperature setting, and check the response of A/C system.	Does the A/C system respond quickly?	A/C system is normal.	Ref. to COMPARTMENT TEMPERATURE DOES NOT CHANGE, OR A/C SYSTEM DOES NOT RESPOND PROMPTLY , Diagnostics for A/C System Malfunction.

NOTE
When freeze frame data is displayed with DTC, record all the data.

DIAGNOSTIC PROCEDURE

CAUTION

Never connect the battery in reverse polarity. Doing so may immediately damage the A/C control module.
Do not disconnect the battery terminals while the engine is running. A large counter electromotive force will be generated in the generator, and this voltage may damage electronic parts such as A/C control module etc.
Before disconnecting the connectors of sensors and the A/C control module, be sure to turn off the ignition switch. A/C control module may be damaged.
Every A/C-related part is a precision part. Do not drop them.
Airbag system wiring harness is routed near the A/C control panel and junction box. CAUTION: Do not use electrical test devices on airbag system wiring harnesses or connectors. Be careful not to damage the airbag system wiring harness when servicing the A/C control panel and junction box.

BATTERY

Measure the battery voltage and specific gravity of the electrolyte. Standard voltage: 12 V Specific gravity: 1.260 or more
Check the condition of the fuses for A/C system power supply and other fuses.
Check the condition of harness and harness connector connections.

Scheme 16

Scheme 16: ASPIRATOR HOSE

Scheme 17

Turn the ignition switch to ON, and press the A/C switch.
Turn the temperature control switch to maximum hot position.
Set the blow vents to the DEF position.
Set the FAN switch to the MAX position.
Put a strip of paper close to the front side of in-vehicle sensor suction port (A) located in the instrument panel lower cover, and check that air is being sucked into the port by seeing the paper moving towards the port. NOTE: Be careful not to let the paper get sucked into the port.
If the paper does not move at all, remove the instrument panel lower cover Ref. to «REMOVAL»(ref-371913-S16002500292010091900000) , Instrument Panel Lower Cover. and check for poor connection of the aspirator hose (A), in-vehicle sensor and heater unit, and repair them if necessary.

A/C LINE

Check the connection for A/C line (A) and lower side high-pressure pipe.

Scheme 18

Scheme 18: A/C LINE

CONTROL LINKAGE

Check the state of mode door linkage.
Check the state of air mix door linkage.
Check the state of FRESH/RECIRC door linkage.

CONTROL SWITCHES

Start the engine and warm up completely.

Inspection using switches SWITCH OPERATION CHART No. Point to check Switch operation Judgment standard 1 OFF switch Press the OFF switch. Setting temperature display goes out. Blower fan: OFF Inlet opening: FRESH Compressor: OFF 2 AUTO switch, driver's side temperature control switch, and passenger's side temperature control switch Press the AUTO switch. Press the temperature control switch to set to LO (maximum cool position). FULL AUTO display illuminates. Outlet air temperature: COOL Blower fan: HI(AUTO) Outlet opening: FACE Inlet opening: AUTO Compressor: AUTO 3) Press the temperature control switch to change the setting from LO (maximum cool position) to HI. Outlet air temperature: COOL --> HOT Blower fan: AUTO Outlet opening: FACE --> B/L --> FOOT Inlet opening: AUTO Compressor: AUTO 4) Press the temperature control switch to set to HI (maximum hot position). Outlet air temperature: HOT Blower fan: HI (AUTO) Outlet opening: FOOT Inlet opening: FRESH (AUTO) Compressor: AUTO 3 Defroster switch Press the defroster switch. Defroster switch indicator illuminates. Outlet air temperature: AUTO Blower fan: AUTO Outlet opening: DEF Inlet opening: FRESH Compressor: ON 4 FRESH/RECIRC switch Press the FRESH/RECIRC switch. Inlet opening switches RECIRC --> FRESH or FRESH --> RECIRC each time pressing the switch. 5 MODE switch Press the MODE switch. Outlet opening switches FACE --> B/L --> FOOT --> F/D each time pressing the switch. 6 FAN switch Press the FAN (+) switch. Blower fan switches LO --> M1 --> M2 --> M3 --> M4 --> HI each time pressing the switch.
Inspection of compressor operation SWITCH OPERATION CHART No. Point to check Switch operation Judgment standard 1 Compressor Turn the A/C switch to ON. Set the FAN switch between LO and HI. Compressor: ON
Inspection of illumination control SWITCH OPERATION CHART No. Point to check Switch operation Judgment standard 1 Illumination Turn the lighting switch to ON. Illumination comes on.

GENERAL TOOL

TOOL NAME	REMARKS
Circuit tester	Used for measuring resistance, voltage and current.

GENERAL TOOL SPECIFICATION

Scheme 19

Scheme 19: ENGINE COMPARTMENT

Scheme 20

Scheme 21

Scheme 21: PASSENGER COMPARTMENT

Scheme 22

Scheme 23

Scheme 23: ELECTRICAL SPECIFICATION

Terminal No.	Description	Measuring condition	Standard
A1	Battery power supply	Ignition switch: OFF	Battery voltage
A2	Ignition power supply	Ignition switch: ON	Battery voltage
A3	ACC power supply	Ignition switch: ACC	Battery voltage
A4	CAN communication (Hi)	Digital signal; can not be measured	(1)
A5	CAN communication (Lo)	Digital signal; can not be measured	(1)
A6	Ground	Always	0 V
A7	A/C control panel communication	Digital signal; can not be measured	(1)
A11	In-vehicle sensor	Ignition switch: ON	25°C: Approx. 1.5 V 40°C: Approx. 1.0 V
A13	Flow sensor	Ignition switch: ON	0.3 - 4.7 V
A14	Air mix door (driver's seat) position signal	Ignition switch: ON, Air mix door: maximum cool position	4 V
A14	Air mix door (driver's seat) position signal	Ignition switch: ON, Air mix door: maximum hot position	1 V
A16	Each potentiometer and sensor power supply	Ignition switch: ON	5 V
A18	A/C control panel communication	Digital signal; can not be measured	(1)
A19	Pressure switch signal	Ignition switch: ON	Normal: ON Abnormal: OFF
A21	After-evaporator sensor signal	Ignition switch: ON, fluctuates depending on temperature after the evaporator.	1 - 4.5 V
A22	Pressure sensor	Ignition switch: ON	0.5 - 4.9 V
A23	Sunload sensor	Ignition switch: ON (0 V: No sunload)	0 - 4.9 V
A24	Sunload sensor (with automatic light)	Ignition switch: ON (0 V: No sunload)	0 - 4.9 V
A25	Air mix door actuator (passenger's seat) position signal	Ignition switch: ON, Air mix door: maximum cool position	4 V
A25	Air mix door actuator (passenger's seat) position signal	Ignition switch: ON, Air mix door: maximum hot position	1 V
A26	Mode door actuator position signal	Ignition switch: ON, Mode door: FACE position	4 V
A26	Mode door actuator position signal	Ignition switch: ON, Mode door: DEF position	1 V
B1	Sensor GND	Always	Less than 0.5 V
B2	Variable compressor solenoid valve	Ignition switch: ON, Blower switch: ON, A/C switch: ON	2 - 12 V
B3	Intake door actuator drive signal (FRESH)	Intake door actuator operating on the FRESH side	0.7 V or less
B4	Air mix door actuator (passenger's seat) drive signal (HOT)	Turning towards HOT side: B4 is 12 V, B16 is GND	While operating: 12 V While not operating: 0 V
B16	Air mix door actuator (passenger's seat) drive signal (COOL)	Turning towards COOL side: B16 is 12 V, B4 is GND	While operating: 12 V While not operating: 0 V
B6	Intake door actuator drive signal (RECIRC)	Intake door actuator operating on the RECIRC side	0.7 V or less
B8	Blower motor voltage feedback	Ignition switch: ON, Blower switch: ON	0.45 - 10 V
B9	Blower motor control signal	Ignition switch: ON, Blower switch: ON	9.05 V
B11	Mode servo drive signal (FACE)	When turning towards FACE side: B11 is 12 V, B13 is GND	While operating: 12 V While not operating: 0 V
B13	Mode servo drive signal (DEF)	When turning towards DEF side: B11 is GND, B13 is 12 V	While operating: 12 V While not operating: 0 V
B20	Heater main relay drive signal	Ignition switch: ON, Blower switch: ON	0.7 V or less
B21	Air mix door actuator (driver's seat) drive signal (COOL)	Turning towards COOL side: B21 is 12 V, B22 is GND	While operating: 12 V While not operating: 0 V
B22	Air mix door actuator (driver's seat) drive signal (HOT)	Turning towards HOT side: B22 is 12 V, B21 is GND	While operating: 12 V While not operating: 0 V
(1) Battery voltage cannot be measured because of digital signal.

(1)	Battery voltage cannot be measured because of digital signal.

CONNECTOR TERMINAL REFERENCE

AIR CONDITIONER A/C MODEL

Ref. to AIR CONDITIONING , WIRING DIAGRAM, Air Conditioning System .

Scheme 24

Scheme 24: OPERATION

SENSOR CHECK TABLE

Note. When the sunload sensor check is performed indoors or in the shade, it could be diagnosed as having an open circuit. Always check the sunload sensor with the sun shining on it.

Display screen (Malfunction at present)	SENSOR	Trouble contents
21/AUTO blinking	In-vehicle sensor	Open
21/AUTO blinking	In-vehicle sensor	Short
22/AUTO blinking	Ambient sensor	Sensor trouble or communication failure
23/AUTO blinking	Evaporator sensor	Open
23/AUTO blinking	Evaporator sensor	Short
24/AUTO blinking	Engine coolant temperature sensor	Sensor trouble or communication failure
25 blinking	Sunload sensor	Open (1)
25/AUTO blinking	Sunload sensor	Short
26/AUTO blinking	Air mix door actuator - potentiometer (driver's)	COOL
26/AUTO blinking	Air mix door actuator - potentiometer (passenger's)	COOL
27/AUTO blinking	Air mix door actuator - potentiometer (driver's)	HOT
27/AUTO blinking	Air mix door actuator - potentiometer (passenger's)	HOT
28/AUTO blinking	Mode door actuator - potensiometer	FACE
29/AUTO blinking	Mode door actuator - potensiometer	DEF
42/AUTO blinking	Pressure sensor	Open (1)
42/AUTO blinking	Pressure sensor	Short circuit (1)
43/AUTO blinking	Flow sensor	Open (1)
43/AUTO blinking		Short circuit (1)
44/AUTO blinking		Faulty
45/AUTO blinking	Sunload sensor	Open
45/AUTO blinking	Sunload sensor	Short
46/AUTO blinking	Variable valve	Open or short circuit (1)
47/AUTO blinking	Air mix door actuator (driver's)	Lock
48/AUTO blinking	Air mix door actuator (passenger's)	Lock
49/AUTO blinking	Mode door actuator	Lock
53/AUTO blinking	Control panel communication	Faulty
54/AUTO blinking	CAN communication	Bus off
55/AUTO blinking	CAN communication	Communication error
20 blinking	When all conditions are normal
(1) Displays current malfunction only.

(1)	Displays current malfunction only.

MALFUNCTION CHART

OPERATING MODE TABLE

Display screen	Blower fan	Mode door	FRESH/RECIRC door	A/C compressor	Air mix door
31	LO	FACE	FRESH	OFF	Cold air
32	LO	FACE	RECIRC	ON	Cold air
33	M1	FACE	RECIRC	ON	Cold air
34	M1	B/L	FRESH	ON	Middle temperature air
35	M1	FOOT	FRESH	ON	Middle temperature air
36	M3	FOOT	FRESH	ON	Hot air
37	M3	F/D	FRESH	ON	Hot air
38	HI	DEF	FRESH	ON	Hot air

OPERATING CHART

LIST

Display item	Unit of measure	Description
Trouble Code		DTC recorded in A/C CM
Engine Speed	RPM	Data value received by CAN
Heater Control Panel Setting Value (Driver's)	LO: 18°C (64°F) HI: 32°C (90°F)	Control panel display value
Heater Control Panel Setting Value (Passenger's)	LO: 18°C (64°F) HI: 32°C (90°F)	Control panel display value
Blower outlet Door Request Temperature	°C (°F)	A/C CM internal setting value
Blower outlet request temperature (Driver's)	°C (°F)	A/C CM internal setting value
Blower outlet request temperature (Passenger's)	°C (°F)	A/C CM internal setting value
Blower Fan Operating Condition	MANU/AUTO	A/C CM input value
A/C Operating Condition	MANU/AUTO	A/C CM input value
Fresh/Recircle Air Operating Condition	MANU/AUTO	A/C CM input value
Mode Operating Condition	MANU/AUTO	A/C CM input value
Rear Defogger	ON/OFF	A/C CM input value
In-vehicle Sensor Temperature	°C (°F)	A/C CM input value
Evaporator Temp.	°C (°F)	A/C CM input value
Quantity of Sunload	W/m 2	A/C CM input value
Refrigerant Pressure	MPa	A/C CM input value
Refrigerant Flow	Kg/h	A/C CM input value
Airmix Door Actuator Position (Driver's)	%	A/C CM input value
Airmix Door Actuator Position (Passenger's)	%	A/C CM input value
Fresh/Recircle Air Door Actuator Position	%	A/C CM input value
Mode Door Actuator Position	%	A/C CM input value
Heater Water Temperature	°C (°F)	Data value received by CAN
Ambient Air Temperature	°C (°F)	Data value received by CAN
Vehicle Speed	Km/h	Data value received by CAN
Accel. Opening Angle	%	Data value received by CAN
Airmix Actuator Position Target (Driver's)	%	A/C CM input value
Airmix Actuator Position Target (Passenger's)	%	A/C CM input value
Fresh/Recircle Air Door Actuator Position Target	%	A/C CM input value
Mode Door Actuator Position Target	%	A/C CM input value
Blower Fan Level	Level	A/C CM output value
Variable Flow Change Solenoid Duty	%	A/C CM output value
Evaporator Temperature Target	°C (°F)	A/C CM input value
Variable Load Compressor Torque Value	Nm	A/C CM input value
Request idle engine speed	RPM	A/C CM output value
Request engine speed	0: No request Cooling H Heating H Cooling L Heating L	A/C CM output value
Discharge pressure	MPa	A/C CM input value
Intake pressure	MPa	A/C CM input value
Cooler request distinction	No request/Request	A/C CM output value
Heater request distinction	No request/Request	A/C CM output value
Break-in variable compressor drive, finish status	Not completed/Completed	A/C CM input value

CURRENT DATA DISPLAY CHART

Note. For detailed operation procedures, refer to PC application help for Subaru Select Monitor.

DTC	Contents	Content of diagnosis	Index
B1601	In-Vehicle Sensor Short	In-vehicle air temperature sensor circuit is shorted.	Ref. to DTC B1601 IN-VEHICLE SENSOR SHORT , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1602	In-Vehicle Sensor Open	In-vehicle air temperature sensor circuit is open.	Ref. to DTC B1602 IN-VEHICLE SENSOR OPEN , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1603	Evaporator Sensor Circuit Short	Evaporator sensor circuit is shorted.	Ref. to DTC B1603 EVAPORATOR SENSOR SHORT , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1604	Evaporator Sensor Circuit Open	Evaporator sensor circuit is open.	Ref. to DTC B1604 EVAPORATOR SENSOR OPEN , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1605	Refrigerant Pressure Sensor Circuit Open	Pressure sensor circuit is open.	Displays current malfunction only. Ref. to DTC B1605 REFRIGERANT FLOW SENSOR CIRCUIT OPEN , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1606	Refrigerant Pressure Sensor Circuit Short	Pressure sensor circuit is shorted.	Displays current malfunction only. Ref. to DTC B1606 REFRIGERANT FLOW SENSOR CIRCUIT SHORT , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1607	Sunload Sensor Short	Sunload sensor circuit is shorted. No sunload	Ref. to DTC B1607 SUNLOAD SENSOR SHORT , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1608	Sunload Sensor Open	Sunload sensor circuit is open.	Ref. to DTC B1608 SUNLOAD SENSOR OPEN , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1610	Airmix Door Actuator Potentiometer Circuit Open (Driver's)	Airmix door actuator - potentiometer circuit is open.	Ref. to DTC B1610 AIRMIX DOOR ACTUATOR POTENTIOMETER CIRCUIT OPEN (DRIVER'S) , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1611	Airmix Door Actuator Potentiometer Circuit Short (Driver's)	Airmix door actuator - potentiometer circuit is shorted.	Ref. to DTC B1611 AIRMIX DOOR ACTUATOR POTENTIOMETER CIRCUIT SHORT (DRIVER'S) , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1612	Airmix Door Actuator Lock (Driver's)	Mode door actuator is locked.	Ref. to DTC B1612 AIRMIX DOOR ACTUATOR LOCK (DRIVER'S) , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1613	Airmix Door Actuator Potentiometer Circuit Open (Passenger's)	Airmix door actuator - potentiometer circuit is open.	Ref. to DTC B1613 AIRMIX DOOR ACTUATOR POTENTIOMETER CIRCUIT OPEN (PASSENGER'S) , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1614	Airmix Door Actuator Potentiometer Circuit Short (Passenger's)	Airmix door actuator - potentiometer circuit is shorted.	Ref. to DTC B1614 AIRMIX DOOR ACTUATOR POTENTIOMETER CIRCUIT SHORT (PASSENGER'S) , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1615	Airmix Door Actuator Lock (Passenger's)	Mode door actuator is locked.	Ref. to DTC B1615 AIRMIX DOOR ACTUATOR LOCK (PASSENGER'S) , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1620	Mode Door Actuator Potentiometer Circuit Open	Mode door actuator - potentiometer circuit is open.	Ref. to DTC B1620 MODE DOOR ACTUATOR POTENTIOMETER CIRCUIT OPEN , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1621	Mode Door Actuator Potentiometer Circuit Short	Mode door actuator - potentiometer circuit is shorted.	Ref. to DTC B1621 MODE DOOR ACTUATOR POTENTIOMETER CIRCUIT SHORT , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1622	Mode Door Actuator Lock	Mode door actuator is locked.	Ref. to DTC B1622 MODE DOOR ACTUATOR LOCK , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
U0001	CAN Communication Bus Off	CAN communication bus off	Displays current malfunction only. Ref. to DTC U0001 CAN COMMUNICATION BUS OFF , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
U0002	CAN Communication Error	CAN communication error Displays current malfunction only.	Ref. to DTC U0002 CAN COMMUNICATION ERROR , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
U0028	Heater Control Panel Communication Error	Communication with heater control panel is faulty.	Displays current malfunction only. Ref. to DTC U0028 HEATER CONTROL PANEL COMMUNICATION ERROR , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1641	Refrigerant Flow Sensor Circuit Short	Refrigerant flow sensor circuit is shorted.	Displays current malfunction only. Ref. to DTC B1641 REFRIGERANT FLOW SENSOR CIRCUIT SHORT , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1642	Refrigerant Flow Sensor Circuit Open	Refrigerant flow sensor circuit is open.	Displays current malfunction only. Ref. to DTC B1642 REFRIGERANT FLOW SENSOR CIRCUIT OPEN , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1643	Variable Flow Change Solenoid Duty Circuit abnormal	Variable flow change solenoid duty circuit is open or shorted.	Displays current malfunction only. Ref. to DTC B1643 VARIABLE FLOW CHANGE SOLENOID DUTY CIRCUIT ABNORMAL , Diagnostic Procedure with Diagnostic Trouble Code (DTC).
B1644	Refrigerant not sealed drive error	Compressor is rotated before filling refrigerant.	Ref. to DTC B1644 REFRIGERANT NOT SEALED DRIVE ERROR , Diagnostic Procedure with Diagnostic Trouble Code (DTC).

DTC CHART

HVAC System (Auto AC) (Diagnostics): Other Subaru Outback BR