Heating/Air Conditioning System Description Without Climate Control

The air conditioning system removes heat from the passenger compartment by circulating refrigerant through the system.

 

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.

 

A/C Pressure Sensor


The A/C pressure sensor converts A/C pressure into electrical signals to the ECM/PCM.

 

The response of the A/C pressure sensor is shown in the graph.

 

Heating/Air Conditioning Door Positions

 

 

HVAC Control Unit Inputs and Outputs

 

Cavity Wire color Signal 
BLK AIR MIX POTENTIAL +5 V OUTPUT 
BRN EVAPORATOR TEMPERATURE SENOR OUTPUT 
ORN MODE 1 OUTPUT 
LT GRN MODE 2 OUTPUT 
PUR MODE 3 OUTPUT 
BLU MODE 4 OUTPUT 
BLU BLOWER FEEDBACK INPUT 
YEL POWER TRANSISTOR CONTROL OUTPUT 
——— ——— ——— 
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