Honda Civic 2006 Service Manual
Heating/Air Conditioning System Description Without Climate Control (With A/C: Without Climate Control)Heating/Air Conditioning System Description Without Climate Control
The air conditioning system removes heat from the passenger compartment by circulating refrigerant through the system.
EXPANSION VALVE
(Meters the required amount of
refrigerant into the evaporator)RECEIVER/DRYER
DESICCANT
(Traps debris, and
removes moisture)A/C COMPRESSOR
(Suction and compression)A/C CONDENSER
(Radiation of heat)A/C PRESSURE SENSOR
(Triple function)
When the refrigerant is below
196 kPa (2.0 kgf/cm2, 28 psi)
or above 3,140 kPa (32 kgf/cm2,
455 psi), the A/C pressure
switch opens the circuit to
the A/C switch and stops the
air conditioning to protect the
A/C compressor.
When the refrigerant is above
1,470 kPa (15.0 kgf/cm2, 213 psi),
the A/C pressure sensor
switches the radiator and
A/C condenser fans to high speed.BLOWER FANEVAPORATOR
(Absorption of heat)EVAPORATOR TEMPERATURE SENSORRELIEF VALVE
(Relieves pressure at the A/C compressor
when the pressure is too high)HIGH PRESSURE VAPORHIGH PRESSURE LIQUIDLOW PRESSURE LIQUIDLOW PRESSURE VAPOR This vehicle uses HFC-134a (R-134a) refrigerant, which does not contain chlorofluorocarbons. Pay attention to the following service items:
- Do not mix refrigerants CFC-12 (R-12) and HFC-134a (R-134a). They are not compatible.
- Use only the recommended polyalkyleneglycol (PAG) refrigerant oil (SANDEN SP-10) designed for the R-134a A/C compressor. Intermixing the recommended (PAG) refrigerant oil with any other refrigerant oil will result in A/C compressor failure.
- All A/C system parts (A/C compressor, discharge line, suction line, evaporator, A/C condenser, receiver/dryer, expansion valve, O-rings for joints) are designed for refrigerant R-134a. Do not exchange with R-12 parts.
- Use a halogen gas leak detector designed for refrigerant R-134a.
- R-12 and R-134a refrigerant servicing equipment are not interchangeable. Use only a recovery/recycling/charging station that is U.L.-listed and is certified to meet the requirements of SAE J2210 to service the R-134a air conditioning systems.
- Always recover refrigerant R-134a with an approved recovery/recycling/charging station before disconnecting any A/C fitting.
Oil Separator
Oil emission from the A/C compressor to the A/C line is reduced by placing the oil separator in the A/C compressor. This results in a thinner oil film inside of the heat exchanger (A/C condenser and evaporator). Air conditioning efficiency is increased without sacrificing engine peformance.
The response of the A/C pressure sensor is shown in the graph.
-99
(-1)
[-14]0196
(2)
[28]3,138
(32)
[455]kPa
(kgf/cm2)
[psi]V4.5750.6840.4250.2945OUTPUT
VOLTAGE
(Vout)Vcc 5 VVoutGNDA/C PRESSURE Heating/Air Conditioning Door Positions
HOTCOOL(VENT)(HEAT/VENT)(HEAT)DEFROSTER
DOORAIR MIX
DOORHEAT/VENT
DOOR
HVAC Control Unit Inputs and Outputs
HVAC CONTROL UNIT 24P CONNECTORWire side of female terminals | Cavity | Wire color | Signal |
|---|
| 1 | BLK | AIR MIX POTENTIAL +5 V | OUTPUT |
| 2 | BRN | EVAPORATOR TEMPERATURE SENOR | OUTPUT |
| 3 | ORN | MODE 1 | OUTPUT |
| 4 | LT GRN | MODE 2 | OUTPUT |
| 5 | PUR | MODE 3 | OUTPUT |
| 6 | BLU | MODE 4 | OUTPUT |
| 7 | BLU | BLOWER FEEDBACK | INPUT |
| 8 | YEL | POWER TRANSISTOR CONTROL | OUTPUT |
| 9 | ——— | ——— | ——— |
| 10 | ——— | ——— | ——— |
| 11 | BRN*1 BLU*2 | A/C SIGNAL | OUTPUT |
| 12 | RED | ILLUMI (-) | OUTPUT |
| 13 | RED | SENSOR COMMON GROUND | INPUT |
| 14 | WHT | MODE VENT | OUTPUT |
| 15 | GRN | MODE DEF | OUTPUT |
| 16 | ORN | RECIRCULATE | INPUT |
| 17 | PUR*1 RED*2 | FRESH | INPUT |
| 18 | GRY | AIR MIX POTENTIAL | OUTPUT |
| 19 | LT BLU | AIR MIX COOL | OUTPUT |
| 20 | PNK | AIR MIX HOT | OUTPUT |
| 21 | BLK | GROUND (G504) | OUTPUT |
| 22 | BRN*1 GRY*2 | REAR WINDOW DEFOGGER RELAY | INPUT |
| 23 | LT GRN*1 PUR*2 | IG2 (Power) | INPUT |
| 24 | GRY | ILLUMI (+) | INPUT |
| *1: | LHD type |
| *2: | RHD type |