Subaru BRZ 2013 · Service Manual Interior body & electrical

Heater & air conditioner system (for manual air conditioning system)

Parts location System information Troubleshooting Circuit diagnosis Removal / installation

AIR CONDITIONER
HEATER & AIR CONDITIONER SYSTEM (FOR MANUAL AIR CONDITIONING SYSTEM)
FUNCTION INSPECTION
1. Check of cooling performance
(1) Install the air conditioner tool set to the vehicle.
(2) Set the vehicle to the following conditions. [Preparatory Code #1]
Item
 Conditions
Vehicle body
 Vehicle parked condition in shade
Door
 Full open
A/C switch
 ON
Engine speed
 2000 r/min
FRESH/RECIRC damper position
 RECIRC position
Outlet opening damper position
 FACE
Setting temperature
 LO (MAX COLD)
Blower speed
 HI
Air conditioner inlet opening temperature *2
 30 to 35°C {86 to 95°F}
Condenser pressure (gauge high pressure side) *3
 1.47 to 1.67 MPa (15 to 17 kgf/cm2)
NOTE:
*2···The inlet opening temperature can be judged correctly only in the range from 30 to 35°C {86 to 95°F}. If the temperature is low, postpone the test.
*3···If the condenser pressure (gauge high pressure side) is high, reduce the pressure by watering the condenser. If it is too low, increase the pressure by placing a cover over the condenser.
(3) Place a wet-and-dry-bulb thermometer (necessary for humidity) at the inlet opening and measure the temperature by inserting the bulb of the dry thermometer at the center of the outlet opening.
(4) Operate the air conditioner under the conditions in [*1] to make the outlet opening temperature stable. (About 5 to 6 minutes)
(5) Measure the dry and wet bulb temperatures at the inlet opening and the temperature at the outlet opening.
(6) Obtain the relative humidity by applying the measurement values of the dry/wet bulb temperatures at the inlet opening to the air diagram.
Captions in illustration
*a
 Dry bulb temperature (°C {°F})
 *b
 Wet bulb temperature (°C {°F})
*c
 Relative humidity (%)
 -
 -
(a) For relative humidity, when the dry bulb temperature of the wet-and-dry-bulb thermometer at the inlet opening is 25°C {77°F} and the wet bulb temperature is 19.5°C {67.1°F}, the intersection of the broken lines in the figure is the relative humidity. In this case, it is 60%.
Captions in illustration
*a
 Example
*b
 Dry bulb temperature (°C {°F})
*c
 Wet bulb temperature (°C)
(7) Check the cooling performance by applying the difference of measured temperatures between inlet opening and outlet opening and the relative humidity to the standard performance table.
Captions in illustration
*a
 Difference between inlet opening and outlet opening temperatures (°C {°F})
 *b
 Relative humidity (%)
Criteria :  The value must be within the shaded area of the diagram.
(a) To obtain the cooling performance using the standard performance table, an example when the difference of temperatures between the inlet opening and the outlet opening is 17°C {30.6°F} and the relative humidity is 60% is shown below.
Captions in illustration
*a
 Difference between inlet opening and outlet opening temperatures (°C {°F})
*b
 Relative humidity (%)
*c
 Intersection
2. Check of refrigerant gas pressure
(1) Check of refrigerant gas pressure with gauge
Captions in illustration
*a
 Gauge reading reference data
 *b
 Pressure at low pressure side MPa {kgf/cm2}
*c
 Pressure at high pressure side MPa {kgf/cm2}
 *d
 Blower HI range
*e
 Blower LO range
 -
 -
(a) Attach the air conditioner tool set.
(b) Set the vehicle to the following conditions. [Preparatory Code #2]
Item
 Conditions
Engine
 After warming-up
Door
 Full open
A/C
 ON
Engine speed
 2000 r/min
RECIRC switch
 RECIRC position
Setting temperature display
 LO (MAX COLD)
Blower speed
 HI
Air conditioner inlet opening temperature
 30 to 35°C {86 to 95°F}
(c) Check the gauge value in [*2].
Standard value :  0.13 to 0.20 MPa (1.3 to 2.0 kgf/cm2) (Low pressure side) :  1.47 to 1.67 MPa (15 to 17 kgf/cm2) (High pressure side)
Captions in illustration
*a
 Low pressure side
*b
 High pressure side
NOTE:
The standard value indicates the normal charge level of refrigerant gas.
(d) Check the gauge value in [*2].
NOTE:
The gauge reading indicates moisture inclusion in the cooling system.
Measurement result
Symptoms
 Cause
 Diagnosis
 Corrective action
During operation, the pressure at the low pressure side becomes vacuum or normal.
 Moisture in the cooling system is frozen at the expansion valve. The refrigerant does not circulate temporarily. After ice is melted, normal operation is recovered.
·The cooler drier is over-saturated.
·Moisture of the cooling system is frozen at the expansion valve and it blocks circulation of the refrigerant gas.
1. Replace the cooler dryer.
2. Remove moisture in the cycle by repeating air release.
3. Inject appropriate level of new refrigerant gas.
Captions in illustration
*a
 Low pressure side
*b
 High pressure side
(e) Check the gauge value in [*2].
Measurement result
Symptoms
 Cause
 Diagnosis
 Corrective action
·Both high and low pressure sides are low.
·Cooling performance is not sufficient.
 A part of the cooling system has gas leak.
·Refrigerant gas is insufficient.
·Leak of refrigerant gas
·Check for gas leak. Repair it if necessary.
·If the pressure value is close to 0 when connected to the gauge, check for the leak area. After repair, perform vacuuming.
·Inject appropriate level of new refrigerant gas.
Captions in illustration
*a
 Low pressure side
*b
 High pressure side
(f) Check the gauge value in [*2].
Measurement result
Symptoms
 Cause
 Diagnosis
 Corrective action
·Both high and low pressure sides are low.
·The pipe connected from the cooler condenser to the A/C unit has frost.
 Dust in the cooler condenser core blocks flow of refrigerant.
 Clogged cooler condenser core
 Replace the cooler condenser ASSY.
Captions in illustration
*a
 Low pressure side
*b
 High pressure side
(g) Check the gauge value in [*2].
NOTE:
The gauge reading indicates no circulation of refrigerant gas.
Measurement result
Symptoms
 Cause
 Diagnosis
 Corrective action
·The pressure at the low pressure side shows vacuum and the pressure at the high pressure side shows very low pressure.
·Pipes before and after the cooler condenser core or cooler expansion valve have frost or condensation.
·Flow of the refrigerant gas is blocked by moisture or dust of the cooling system.
·Flow of the refrigerant gas is blocked by leak of the refrigerant gas from the cooler expansion valve.
Refrigerant gas does not circulate.
1. Check the cooler expansion valve.
2. Remove dust in the cooler expansion valve with an air gun.
3. Replace the cooler condenser core.
4. After vacuuming, inject new refrigerant gas to the appropriate level.
5. If leak of the refrigerant gas from the cooler expansion valve is found, replace the cooler expansion valve.
Captions in illustration
*a
 Low pressure side
*b
 High pressure side
(h) Check the gauge value in [*2].
NOTE:
The gauge reading indicates excessive refrigerant gas or insufficient cooling of the cooler condenser core.
Measurement result
Symptoms
 Cause
 Diagnosis
 Corrective action
·Both high and low pressure sides are too high.
·Excessive refrigerant
·Cooling of the cooler condenser core is insufficient.
·Excessive refrigerant
·Cooling malfunction of cooler condenser core
1. Clean the cooler condenser core fin.
2. Check operation of the condenser fan motor.
3. When 1 and 2 are normal, check the refrigerant level and inject the refrigerant to the appropriate level.
Captions in illustration
*a
 Low pressure side
*b
 High pressure side
(i) Check the gauge value in [*2].
NOTE:
The gauge reading indicates air inclusion in the refrigerant system.
Measurement result
Symptoms
 Cause
 Diagnosis
 Corrective action
·Both high and low pressure sides are too high.
·The low pressure pipe is too hot to be touched.
 Air inside the cooling system
·Air is included inside the cooling system.
·Insufficient vacuuming
1. Check if the compressor oil is contaminated or insufficient.
2. After vacuuming, inject new refrigerant gas.
Captions in illustration
*a
 Low pressure side
*b
 High pressure side
(j) Check the gauge value in [*2].
NOTE:
The gauge reading indicates improper operation of the cooler expansion valve.
Measurement result
Symptoms
 Cause
 Diagnosis
 Corrective action
·Both high and low pressure sides are too high.
·The low pressure side has frost or condensation.
 Problems on cooler expansion valve
·Excessive refrigerant of low pressure pipe
·Excessive opening of cooler expansion valve
 Replace the cooler expansion valve.
Captions in illustration
*a
 Low pressure side
*b
 High pressure side
(k) Check the gauge value in [*2].
NOTE:
The gauge reading indicates improper compression of the compressor ASSY (with pulley).
Measurement result
Symptoms
 Cause
 Diagnosis
 Corrective action
·Both high and low pressure sides are too high.
·Pressure of the high pressure side is too low.
 Leak in compressor ASSY (with pulley)
·Poor compression
·Leak from valve or damage to sliding part
·Improper operation of pulley limiter or control valve
 Repair or replace the compressor ASSY (with pulley).
Captions in illustration
*a
 Low pressure side
*b
 High pressure side
NOTE:
·The gauge reading indicates improper compression of the compressor ASSY (with pulley).
·When there is no change in the pressure at the low and high pressure side, the compressor ASSY (with pulley) is not discharging and the pulley limiter is activated.
3. Cooler condenser ASSY
(1) If the cooler condenser ASSY fin is contaminated, clean it with water and dry it with compressor air.
CAUTION:
Do not damage the fin of the cooler condenser ASSY.
(2) If the fin of the cooler condenser ASSY is bent, correct the fin straight with a screwdriver or pliers.
4. Check for refrigerant gas leak
(1) Using a halogen leak detector, check the pipe joints for leaks.
(2) If gas leak is found at joints of pipes, check the torque at the joints.
PARTS LOCATION
SYMPTOM TABLE
Manual A/C
Symptoms
 Inspection items
 Reference pages
A/C system does not operate at all.
 Fuse [HEATER (50 A, HEATER (10 A), HEATER-S)]
  
Wire harness and connector
 -
Heater control SUB-ASSY
  
Heater control SUB-ASSY NO.1
  
Heater control SUB-ASSY NO.3
  
CAN communication system
  
Main body ECM
  
Switch operation is not accepted.
 Heater control SUB-ASSY
  
Heater control SUB-ASSY NO.1
  
Heater control SUB-ASSY NO.3
  
Wire harness and connector
 -
Blower motor (with fan) does not rotate.
 Blower motor SUB-ASSY (with fan)
  
Heater control SUB-ASSY
  
Blower motor circuit
  
Blower resistor
  
Blower motor (with fan) speed does not change.
 Heater control SUB-ASSY
  
Blower motor circuit
  
Blower resistor
  
Difficult cooling
 Check of refrigerant level *1
  
Check of refrigerant pressure *1
  
Cooler expansion valve *1
 -
Cooler compressor ASSY *1
  
Main body ECM
  
Cold air not emitted
 Check of refrigerant level *1
  
Check of refrigerant pressure *1
  
Heater control SUB-ASSY NO.3*1
  
Air conditioner pressure switch circuit *1
  
Compressor ASSY (with pulley) *1
  
Cooler expansion valve *1
 -
Main body ECM
  
Heater relay *1
  
CAN communication system *1
  
Wire harness and connector
 -
Inlet opening is not changed.
 Wire harness and connector
 -
Damper servo (FRESH/RECIRC)
  
Heater control SUB-ASSY NO.1
  
Indicator does not illuminate.
 Heater control SUB-ASSY
  
Heater control SUB-ASSY NO.1
  
Heater control SUB-ASSY NO.3
  
Wire harness and connector
 -
Illumination does not turn on, or does not dim.
 Heater control SUB-ASSY
  
Heater control SUB-ASSY NO.1
  
Heater control SUB-ASSY NO.3
  
Wire harness and connector
 -
*1: With cooler
HOW TO TROUBLESHOOT
1. Bring in the car


Next▼

2. Interview and phenomenon check

(1) Interview and phenomenon check (Refer to )

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3. Preliminary inspection

(1) Inspect the battery voltage.
Standard value :  11 to 14 V
(2) According to the parts arrangement drawing and/or circuit figure, check the blown fuse, broken wire harness, short circuit, and/or improper connection that can be inspected visually.

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4. Inspection of CAN communication system

(1) Check CAN communication system. (Refer to )
Result
Result
 Go to
Functioning properly
 A
Not functioning properly
 B
B
>Go to the CAN communication system section (Refer to )

A▼

5. Symptom table

(1) Symptom table (Refer to )
Result
Result
 Go to
Not applicable to the symptom table.
 A
Applicable to the symptom table.
 B
B
>Go to Step 7.

A▼

6. Perform troubleshooting with the method below based on malfunctions.

(1) [Current Data Display & Save] / [System Operation Check Mode] (Refer to )
(a) Current data display & save (SSM3)
(2) ECM terminal matrix (Refer to )

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7. Adjustment, repair, or replacement


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8. Confirmation test


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Complete

CHECK LIST FOR INTERVIEW
CIRCUIT FIGURE
CURRENT DATA DISPLAY & SAVE / SYSTEM OPERATION CHECK MODE
1. Current data display & save (SSM3)
(1) Using SSM3, display the [Current Data Display & Save] screen. Check the computer data.
SSM3 screen: [Each System Check]→ [Integ. unit mode]→ [Current Data Display & Save]
Item Name
[Symbol]
 Description/display range
 Normal value
 Remarks
[evaporator sensor voltage]
 Evaporator ambient temperature is displayed.
Display range: 0 to 21.4°C
·In open circuit: (0°C) is displayed.
·In short-circuit: (21.4°C) is displayed.
 Cooler thermistor NO.1 (after-evaporator sensor) system
[A/C SW Input]
 Air conditioner switch input
Display: ON - OFF
 Display: ON - OFF
 The air conditioner signal system may have an error, if any.
[A/C SW Output]
 Air conditioner switch output
Display: ON - OFF
 Display: ON - OFF
 The air conditioner signal system may have an error, if any.
SSM3 display: [Each System Check] → [Engine Control System] → [Current Data Display & Save]
Item Name
[Symbol]
 Description/display range
 Normal value
 Remarks
[A/C Mid Pressure Switch]
 Pressure switch status is displayed.
Display: ON - OFF
 ON: Pressure switch ON
OFF: Pressure switch OFF
 The pressure switch system or refrigerant quantity may be abnormal, if any.
[A/C Switch]
 Air conditioner switch status is displayed.
Display: ON - OFF
 ON: Air conditioner ON
OFF: Air conditioner OFF
 The air conditioner signal system may have an error, if any.
[A/C Compressor Signal]
 The magnet clutch status is displayed.
Display: ON - OFF
 ON: Magnet clutch ON
OFF: Magnet clutch OFF
 The magnet clutch system may be abnormal, if any.
[Air Conditioner FB Val]
 The ISC valve status is displayed.
Display range: -150 to 149.99
 -
 -
2. System Operation Check Mode
(1) Using SSM3, display the [System Operation Check Mode] screen according to the screen and perform the system operation check.
SSM3 screen: [Each System Check] → [Engine Control System] → [Work Support] → [System Operation Check Mode]
Item Name
 Drive
[A/C Compressor Relay]
 Magnet clutch operation
ON - OFF
Blower motor circuit
Circuit description
When the heater control SUB-ASSY is operated from 0 → 1 or more, the blower motor relay turns ON. The power is supplied to the blower motor SUB-ASSY (with fan) and it starts rotating. Speed of the blower motor SUB-ASSY (with fan) is controlled by operating the heater control SUB-ASSY and switching the ground - blower register circuits.
Circuit figure
Inspection steps
CAUTION:
Before performing the troubleshooting, check the fuse of this circuit.
2. Unit inspection of blower motor SUB-ASSY (with fan)

(1) Disconnect connector A31 of the blower motor SUB-ASSY (with fan).
(2) Inspect the individual blower motor SUB-ASSY (with fan). (Refer to )
NG
>Replacement of blower motor SUB-ASSY (with fan) (Refer to )

OK▼

3. Inspection of wire harness and connector (HEATER fuse - blower motor relay)

NOTE:
For inspection procedures and precautions, refer to .
(1) Remove the blower motor relay.
(2) Measure the voltage between the terminals.
Voltage
Inspection terminals
 Inspection conditions
 Standard value
5 - Chassis ground
 Always
 11 to 14 V
1 - Chassis ground
 IG ON
 11 to 14 V
Captions in illustration
*a
 Connector not connected
(Blower motor relay)
NG
>Repair or replacement of wiring harness or connector

OK▼

12. Unit inspection of heater control SUB-ASSY (blower switch)

(1) Inspect the individual heater control SUB-ASSY (blower switch). (Refer to )
NG
>Replacement of heater control SUB-ASSY (Refer to )

OK▼
Go to the related circuit test listed on the symptom table. (Refer to )

Magnet clutch relay circuit
Circuit description
The main body ECM (network gateway computer) transmits the magnet clutch ON command to the engine control computer through the CAN communication. The engine control computer operates the heater relay and turns ON the magnet clutch.
Circuit figure
Inspection steps
CAUTION:
·Before performing the troubleshooting, check the fuse of this circuit.
·The heater & air conditioner system uses the CAN communication system. First, according to “How to troubleshoot”, inspect the “Communication function” and make sure that there is no problem in the communication system before troubleshooting.
·This inspection may be affected by abnormality of the engine control computer and the main body ECM (network gateway computer). Before inspection, check the diagnostic codes of “engine” and “main body” to make sure that they are normal.
4. Inspection of wire harness and connector (heater control SUB-ASSY NO.3 - main body ECM (network gateway computer))

NOTE:
For inspection procedures and precautions, refer to .
(1) Inspect the voltage between connector terminals at the vehicle wire harness side.
Voltage
Inspection terminals
 Inspection conditions
 Standard value
D6-17 - Chassis ground
 IG ON
Blower switch LO
A/C ON
 10 to 16 V
Captions in illustration
*a
 Connector connected
(Connector connected to main body ECM (network gateway computer))
NG
>Repair or replacement of wiring harness or connector

OK▼

6. Unit inspection of heater relay

(1) Inspect the individual heater relay. (Refer to )
NG
>Replacement of heater relay

OK▼

7. Inspection of wire harness and connector (heater relay - engine control computer)

NOTE:
For inspection procedures and precautions, refer to .
(1) Remove the heater relay from the engine compartment relay block.
(2) Disconnect connector A35 from the engine control computer.
(3) Inspect the resistance between connector terminals at the vehicle wire harness side.
Resistance
Inspection terminals
 Inspection conditions
 Standard value
1 - A35-35(AC)
 Always
 Less than 1 Ω
1 - Chassis ground
 Always
 10 kΩ or more
Captions in illustration
*1
 Engine compartment relay block
*2
 Heater relay
NG
>Repair or replacement of wiring harness or connector

OK▼

11. Inspection of wire harness and connector (compressor ASSY (with magnet clutch) - heater relay)

NOTE:
For inspection procedures and precautions, refer to .
(1) Inspect the voltage between connector terminals at the vehicle wire harness side.
Resistance
Inspection terminals
 Inspection conditions
 Standard value
C17-1(MG+) - 3
 Always
 Less than 1 Ω
C17-1 (MG+) - Chassis ground
 Always
 10 kΩ or more
NG
>Repair or replacement of wiring harness or connector

OK▼
Replacement of the engine control computer (Refer to )