Subaru Outback (BR): HVAC System - List of Diagnostic Trouble Code (DTC)

A: LIST

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 in direct sunlight.

NOTE:

*1: When the sunload sensor inspection is performed indoors or in the shade, it may be diagnosed as having an open circuit due to an insufficient light volume. In this case, check the sunload sensor at a location exposed to direct sunlight.
*2: Displays current malfunction only.

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

A: DTC B1601 IN-VEHICLE SENSOR SHORT

DTC DETECTING CONDITION:

In-vehicle sensor circuit is shorted.

TROUBLE SYMPTOM:

• In-vehicle air temperature is falsely recognized as 25ºC (77ºF), and the compartment temperature is adjusted.
• DTC "B1601" Short-circuit in in-vehicle sensor was detected.
• DTC "-21" Short-circuit in in-vehicle sensor was detected.

WIRING DIAGRAM:

B: DTC B1602 IN-VEHICLE SENSOR OPEN

DTC DETECTING CONDITION:

In-vehicle sensor circuit is open.

TROUBLE SYMPTOM:

• In-vehicle air temperature is falsely recognized as 25ºC (77ºF), and the compartment temperature is adjusted.
• DTC "B1602" Open circuit in in-vehicle sensor was detected.
• DTC "21" Open circuit in in-vehicle sensor was detected.

WIRING DIAGRAM:

C: DTC B1603 EVAPORATOR SENSOR SHORT

DTC DETECTING CONDITION:

Evaporator sensor circuit is shorted.

TROUBLE SYMPTOM:

• Compressor does not operate. (Variable compressor)
• Evaporator temperature is falsely recognized as high, and the compartment temperature is adjusted.
• DTC "B1603" Short-circuit in evaporator sensor was detected.
• DTC "-23" Short-circuit in evaporator sensor was detected.

WIRING DIAGRAM:

D: DTC B1604 EVAPORATOR SENSOR OPEN

DTC DETECTING CONDITION:

Evaporator sensor circuit is open.

TROUBLE SYMPTOM:

• Compressor does not operate.
• Evaporator temperature is falsely recognized as low, and the compartment temperature is adjusted.
• DTC "B1604" Open circuit in evaporator sensor was detected.
• DTC "23" Open circuit in evaporator sensor was detected.

WIRING DIAGRAM:

E: DTC B1605 REFRIGERANT FLOW SENSOR CIRCUIT OPEN

DTC DETECTING CONDITION:

Refrigerant pressure sensor circuit is open.

TROUBLE SYMPTOM:

• Compressor does not operate. (Variable compressor)
• DTC "B1605" Open circuit in refrigerant pressure sensor was detected.
• DTC "42" Open circuit in refrigerant pressure sensor was detected.

WIRING DIAGRAM:

F: DTC B1606 REFRIGERANT FLOW SENSOR CIRCUIT SHORT

DTC DETECTING CONDITION:

Refrigerant pressure sensor circuit is shorted.

TROUBLE SYMPTOM:

• Compressor does not operate. (Variable compressor)
• DTC "B1606" Short-circuit in refrigerant pressure sensor was detected.
• DTC "-42" Short-circuit in refrigerant pressure sensor was detected.

WIRING DIAGRAM:

G: DTC B1607 SUNLOAD SENSOR SHORT

DTC DETECTING CONDITION:

Sunload sensor circuit is shorted.

TROUBLE SYMPTOM:

• Operation is performed as no sunload.
• DTC "B1607" Short-circuit in sunload sensor was detected.
• DTC "-25" Short-circuit in sunload sensor was detected.
• DTC "-45" Short-circuit in sunload sensor (auto light control) was detected.

WIRING DIAGRAM:

H: DTC B1608 SUNLOAD SENSOR OPEN

DTC DETECTING CONDITION:

Sunload sensor circuit is open. (Displayed for current malfunction)

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 in direct sunlight.

TROUBLE SYMPTOM:

• Operation is performed as no sunload.
• DTC "B1608" Open circuit in sunload sensor was detected.
• DTC "25" Open circuit in sunload sensor was detected.
• DTC "45" Open circuit in sunload sensor (auto light control) was detected.

WIRING DIAGRAM:

I: DTC B1610 AIRMIX DOOR ACTUATOR POTENTIOMETER CIRCUIT OPEN (DRIVER'S)

DTC DETECTING CONDITION:

Air mix door actuator potentiometer circuit is open.

TROUBLE SYMPTOM:

• Temperature cannot be adjusted.
• Temperature of the driver's side cannot be adjusted for model with left/right independent air conditioner.
• DTC "B1610" Open circuit in air mix door actuator - potentiometer (driver's) was detected.
• DTC "26" Open circuit in air mix door actuator - potentiometer (driver's) was detected.

WIRING DIAGRAM:

J: DTC B1611 AIRMIX DOOR ACTUATOR POTENTIOMETER CIRCUIT SHORT (DRIVER'S)

DTC DETECTING CONDITION:

Air mix door actuator potentiometer circuit is shorted.

TROUBLE SYMPTOM:

• Temperature cannot be adjusted.
• Temperature of the driver's side cannot be adjusted for model with left/right independent air conditioner.
• DTC "B1611" Short circuit in air mix door actuator - potentiometer (driver's) was detected.
• "27" Short circuit in air mix door actuator - potentiometer (driver's) was detected.

WIRING DIAGRAM:

K: DTC B1612 AIRMIX DOOR ACTUATOR LOCK (DRIVER'S)

DTC DETECTING CONDITION:

• Driver's air mix door actuator is locked.
• The potentiometer value of the actuator does not change.

TROUBLE SYMPTOM:

Temperature of the driver's side cannot be adjusted for model with left/right independent air conditioner.

WIRING DIAGRAM:

L: DTC B1613 AIRMIX DOOR ACTUATOR POTENTIOMETER CIRCUIT OPEN (PASSENGER'S)

DTC DETECTING CONDITION:

Air mix door actuator potentiometer circuit is open.

TROUBLE SYMPTOM:

• Temperature of the passenger's side cannot be adjusted for model with left/right independent air conditioner.
• DTC "B1613" Open circuit in air mix door actuator - potentiometer (passenger's) was detected.
• DTC "-26" Open circuit in air mix door actuator - potentiometer (passenger's) was detected.

WIRING DIAGRAM:

M: DTC B1614 AIRMIX DOOR ACTUATOR POTENTIOMETER CIRCUIT SHORT (PASSENGER'S)

DTC DETECTING CONDITION:

Air mix door actuator potentiometer circuit is shorted.

TROUBLE SYMPTOM:

• Temperature of the passenger's side cannot be adjusted for model with left/right independent air conditioner.
• DTC "B1614" Short circuit in air mix door actuator - potentiometer (passenger's) was detected.
• DTC "-27" Short circuit in air mix door actuator - potentiometer (passenger's) was detected.

WIRING DIAGRAM:

N: DTC B1615 AIRMIX DOOR ACTUATOR LOCK (PASSENGER'S)

DTC DETECTING CONDITION:

Passenger's air mix door actuator is locked.

TROUBLE SYMPTOM:

• Temperature of the passenger's side cannot be adjusted for model with left/right independent air conditioner.
• DTC "B1615" Air mix door actuator - lock (passenger's) was detected.
• DTC "48" Air mix door actuator - lock (passenger's) was detected.

WIRING DIAGRAM:

O: DTC B1620 MODE DOOR ACTUATOR POTENTIOMETER CIRCUIT OPEN

DTC DETECTING CONDITION:

Mode door actuator potentiometer circuit is open.

TROUBLE SYMPTOM:

• Vent does not change.
• DTC "B1620" Open circuit in mode door actuator potentiometer was detected.
• DTC "28" Open circuit in mode door actuator potentiometer was detected.

WIRING DIAGRAM:

P: DTC B1621 MODE DOOR ACTUATOR POTENTIOMETER CIRCUIT SHORT

DTC DETECTING CONDITION:

Mode door actuator potentiometer circuit is shorted.

TROUBLE SYMPTOM:

• Vent does not change.
• DTC "B1621" Short circuit in mode door actuator potentiometer was detected.
• DTC "29" Short circuit in mode door actuator potentiometer was detected.

WIRING DIAGRAM:

Q: DTC B1622 MODE DOOR ACTUATOR LOCK

DTC DETECTING CONDITION:

Mode door actuator locked.

TROUBLE SYMPTOM:

• DTC "B1622" Mode door actuator lock was detected.
• DTC "49" Mode door actuator lock was detected.

WIRING DIAGRAM:

R: DTC U0028 HEATER CONTROL PANEL COMMUNICATION ERROR

DTC DETECTING CONDITION:

UART communication failure

TROUBLE SYMPTOM:

• Unable to operate A/C.
• DTC "U0028" Heater control panel communication failure was detected.
• DTC "53" Heater control panel communication failure was detected.

WIRING DIAGRAM:

• Auto A/C

• Manual A/C

S: DTC U0001 CAN COMMUNICATION BUS OFF

DTC DETECTING CONDITION:

• Data to be received via CAN communication do not arrive.
• A/C cooperation control does not operate.

TROUBLE SYMPTOM:

A/C does not operate fully automatically.

T: DTC U0002 CAN COMMUNICATION ERROR

DTC DETECTING CONDITION:

• Data to be received via CAN communication do not arrive.
• A/C cooperation control does not operate.

TROUBLE SYMPTOM:

A/C does not operate fully automatically.

U: DTC B1641 REFRIGERANT FLOW SENSOR CIRCUIT SHORT

DTC DETECTING CONDITION:

• The voltage of the sensor signal line decreased to 0.3 V or less.
• Short-circuit in flow sensor circuit

TROUBLE SYMPTOM:

• A/C does not function because refrigerant flow amount cannot be measured.
• DTC "B1641" Short-circuit in refrigerant flow sensor was detected.
• DTC "-43" Short-circuit in refrigerant flow sensor was detected.

WIRING DIAGRAM:

V: DTC B1642 REFRIGERANT FLOW SENSOR CIRCUIT OPEN

DTC DETECTING CONDITION:

• The voltage of the sensor signal line increased to 4.7 V or more.
• Short-circuit in flow sensor circuit

TROUBLE SYMPTOM:

• A/C does not function because refrigerant flow amount cannot be measured.
• DTC "B1642" Open circuit in refrigerant flow sensor was detected.
• DTC "43" Open circuit in refrigerant flow sensor was detected.

WIRING DIAGRAM:

W: DTC B1643 VARIABLE FLOW CHANGE SOLENOID DUTY CIRCUIT ABNORMAL

DTC DETECTING CONDITION:

Open or short circuit in variable solenoid valve

TROUBLE SYMPTOM:

• Refrigerant pressure cannot be changed.
• DTC "B1643" Variable flow change solenoid duty circuit failure was detected.
• DTC "46" Variable flow change solenoid duty circuit failure was detected.

WIRING DIAGRAM:

X: DTC B1644 REFRIGERANT NOT SEALED DRIVE ERROR

DTC DETECTING CONDITION:

• Compressor was operated while refrigerant was low.
• Compressor was operated while refrigerant pressure was extremely low.
• Judgment is made only when the delivery mode fuse is installed.

TROUBLE SYMPTOM:

A/C does not operate.

WIRING DIAGRAM:

READ NEXT: