7 Compartment Temperature Is Excessively Lower Than Setting Temperature

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

Trouble symptom:

Compartment temperature is excessively lower than setting temperature.

Trouble causes:

Large airflow capacity
Refrigerant pressure failure
CAN communication failure
A/C control panel failure
Air mix actuator failure
Evaporator sensor failure
In-vehicle sensor failure
Ambient sensor failure
Sunload sensor failure
Heat pump system failure
UART communication failure

Wiring diagram:

Air conditioning system Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV)>AIR CONDITIONING SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to AIR CONDITIONERS (DIAGNOSTICS) (HEV)>GENERAL DESCRIPTION>CAUTION .

Courtesy of SUBARU OF AMERICA, INC.

Courtesy of SUBARU OF AMERICA, INC.

CHECK AIRFLOW CAPACITY .
Check the airflow capacity. Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DIAGNOSTICS WITH PHENOMENON>INSPECTION>AIR GOES OUT OF CONTROL, (BLOWER MOTOR ROTATES AT HIGH SPEED.) .

Is the check result OK?

Yes : Go to 2.

No : Perform repair according to inspection procedure.
CHECK AMOUNT OF REFRIGERANT PRESSURE .
Check the refrigerant pressure. Ref. to AIR CONDITIONER (HEV)>REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET .

Is the check result OK?

Yes : Go to 3.

No : Perform repair according to refrigerant pressure inspection.
CHECK A/C CONTROL PANEL .
1. Set the temperature control dial to MAX COOL.
2. Using the Subaru Select Monitor, check the following items in the [Data Monitor] of [Air Conditioner]. Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DATA MONITOR .
  - Heater Control Panel Setting Value (Driver's)
Does [Heater Control Panel Setting Value (Driver's)] indicate "60"*1?

(*1: For the 72°F center specification. For the 25°C center specification, the value is 18)

Yes : Go to 4.

No : Replace the A/C control panel. Ref. to AIR CONDITIONER (HEV)>CONTROL PANEL .
CHECK A/C CONTROL PANEL .
1. Set the temperature control dial to MAX HOT.
2. Using the Subaru Select Monitor, check the following items in the [Data Monitor] of [Air Conditioner]. Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DATA MONITOR .
  - Heater Control Panel Setting Value (Driver's)
Does [Heater Control Panel Setting Value (Driver's)] indicate "85" *2?

(*2: For the 72°F center specification. For the 25°C center specification, the value is 32)

Yes : Go to 5.

No : Replace the A/C control panel. Ref. to AIR CONDITIONER (HEV)>CONTROL PANEL .
CHECK DTC .
1. Turn to READY ON.
2. Turn the temperature control dial at MAX COOL and leave for 16 seconds or more.
3. Read the following DTCs using Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) . Ref. to P-HEV HYBRID POWERTRAIN CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
  - Air Conditioner
  - P-HEV Hybrid Powertrain Control
Are any DTCs displayed? (Current malfunction)

Yes : Perform the diagnosis for the displayed DTCs. Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) . Ref. to P-HEV HYBRID POWERTRAIN CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

No : Go to 6.
CHECK DTC .
1. Turn the temperature control dial at MAX HOT and leave for 16 seconds or more.
2. Read the following DTCs using Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) . Ref. to P-HEV HYBRID POWERTRAIN CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .
  - Air Conditioner
  - P-HEV Hybrid Powertrain Control
Are any DTCs displayed? (Current malfunction)

Yes : Perform the diagnosis for the displayed DTCs. Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) . Ref. to P-HEV HYBRID POWERTRAIN CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

No : Go to 7.
CHECK EVAPORATOR SENSOR UNIT .
Perform the inspection of evaporator sensor unit. Ref. to AIR CONDITIONER (HEV)>EVAPORATE SENSOR .

Is the check result OK?

Yes : Go to 8.

No : Replace the evaporator sensor. Ref. to AIR CONDITIONER (HEV)>EVAPORATOR .
CHECK IN-VEHICLE SENSOR UNIT .
Check in-vehicle sensor. Ref. to AIR CONDITIONER (HEV)>IN-VEHICLE SENSOR (AUTO A/C MODEL) .

Is the check result OK?

Yes : Go to 9.

No : Replace the in-vehicle sensor. Ref. to AIR CONDITIONER (HEV)>IN-VEHICLE SENSOR (AUTO A/C MODEL) .
CHECK AMBIENT SENSOR UNIT .
Check the ambient sensor. Ref. to AIR CONDITIONER (HEV)>AMBIENT SENSOR .

Is the check result OK?

Yes : Go to 10.

No : Replace the ambient sensor, Ref. to AIR CONDITIONER (HEV)>AMBIENT SENSOR .
CHECK SUNLOAD SENSOR UNIT .
Check the sunload sensor unit. Ref. to AIR CONDITIONER (HEV)>SUNLOAD SENSOR (AUTO A/C MODEL) .

Is the check result OK?

Yes : Go to 11.

No : Replace the sunload sensor. Ref. to AIR CONDITIONER (HEV)>SUNLOAD SENSOR (AUTO A/C MODEL) .
CHECK HEAT PUMP CONTROL MODULE .
1. Turn the ignition switch to OFF.
2. Disconnect the heat pump Control Module connector.
3. Using a tester, measure the voltage between the heat pump Control Module connector and chassis ground.
  Connector & terminal
  
  (i365) No. 40 (+) - Chassis ground (-):
Is the voltage 11 - 14 V or more?

Yes : Go to 12.

No : Repair or replace the open, short circuit of the harness.
CHECK HEAT PUMP CONTROL MODULE .
Replace the heat pump Control Module with a properly functioning part. Ref. to AIR CONDITIONER (HEV)>CONTROL UNIT .

Is the faulty phenomenon reproduced?

Yes : Go to 13.

No : Malfunction occurred in the heat pump Control Module.
PERFORM UNIT INSPECTION OF HEAT PUMP SYSTEM PARTS .
Perform unit inspection of the following parts.
- Low pressure solenoid valve Ref. to AIR CONDITIONER (HEV)>SOLENOID VALVE>INSPECTION .
- High pressure solenoid valve Ref. to AIR CONDITIONER (HEV)>SOLENOID VALVE>INSPECTION .
- Heating expansion valve Ref. to AIR CONDITIONER (HEV)>EXPANSION VALVE>INSPECTION .
- Cooling expansion valve Ref. to AIR CONDITIONER (HEV)>EXPANSION VALVE>INSPECTION .
- Interior condenser exit temperature sensor H Ref. to AIR CONDITIONER (HEV)>PIPE TEMPERATURE SENSOR>INSPECTION .
- Exterior condenser exit temperature sensor Ref. to AIR CONDITIONER (HEV)>PIPE TEMPERATURE SENSOR>INSPECTION .
- Discharge temperature sensor Ref. to AIR CONDITIONER (HEV)>PIPE TEMPERATURE SENSOR>INSPECTION .
- Evaporator exit temperature sensor. Ref. to AIR CONDITIONER (HEV)>PIPE TEMPERATURE SENSOR>INSPECTION .
Is the check result OK?

Yes : The circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.

No : Repair it according to unit inspection of parts.