A/C SYSTEM SPECIFICATIONS
| Application | Specification |
|---|---|
| System Type | Cycling Clutch |
| Compressor Type | Diesel Kiki 6-Cyl. |
| R-12 Capacity | 46 oz. |
| Oil Capacity | 6.8 oz. |
| A/C Belt Deflection | (1) .04-.08" (1-2 mm) |
| (1) With thumb pressure applied at midpoint of belt. | |
| (1) | With thumb pressure applied at midpoint of belt. |
A/C SYSTEM SPECIFICATIONS
DESCRIPTION
| CAUTION | When discharging air conditioning system, use only approved refrigerant recovery/recycling equipment. Make every attempt to avoid discharging refrigerant into the atmosphere. |
Electronic Climate Control (ECC) automatically controls vehicle interior temperature through 4 sensors, vacuum solenoid valve assembly, power unit, air-mix motor and an Electronic Control Unit (ECU). Automatic function can be overriden by selecting desired function on ECU panel. ECC has self-diagnostic ability. The A/C button on ECU control panel will flash, providing 23 different fault codes. (Scheme 1)
Scheme 1
CONTROL PANEL
The control panel contains ECU for automatic operation. Control panel has 3 dials and 2 buttons. Left dial allows selection of automatic ("aut") blower speed , or manual override of 5 set blower speeds and off. When blower speed is set at off, A/C compressor clutch is de-energized. Center dial allows selection of automatic ("aut") operation of air distribution doors, or manual override of floor, bi-level, vent or defrost operation.
Right dial allows the user to select any temperature between 64-80°F (17-27°C). When set to the desired temperature, an electrical signal is sent to the power unit, vacuum solenoid valve assembly and air-mix motor. When temperature selector dial is set to maximum cooling (Blue marking), or maximum heating (Red marking) blower fan will run at high speed only.
The left button allows selection of recirculated air only in all modes except defrost. When button is pushed, outside air is closed off and inside air is recirculated through vehicle interior.
The right button provides for economy operation by disengaging A/C compressor. The indicator light in this button also serves as a fault code indicator.
POWER UNIT
Power unit is mounted on evaporator housing (blower motor housing on 780 series). Power unit amplifies electronic signal from ECU and operates blower motor and A/C compressor clutch. Blower speed is controlled by a power transistor. One relay is used for high blower speed, and one relay for A/C compressor clutch.
SOLENOID VACUUM VALVE ASSEMBLY
Solenoid Vacuum Valve Assembly (SVVA) contains 6 solenoids. ECU signals SVVA of desired mode of operation. SVVA supplies or releases vacuum to 4 mode door vacuum actuators and a coolant valve.
SVVA controls mode door operation in "aut" setting and in manual override. Mode door vacuum actuators are used for defrost/floor, bi-level, vent and recirculation. A small vacuum reservoir is mounted on A/C-heater evaporator cover next to SVVA. (Scheme 2)
Scheme 2
AIR-MIX MOTOR
Air-mix motor operates air blend door in A/C-heater assembly. Signals from a feedback potentiometer in air-mix motor informs ECU of door position. ECU determines if more heated air or cooled air is necessary through sensor inputs, and directs proper position of air-mix door.
A/C-HEATER BLOWER MOTOR CONTROL
Blower motor speed is controlled by power unit and a power transistor. High blower speed electrical signal uses a relay to reduce load on power transistor. In automatic ("aut") mode, blower speed is infinitely variable. In override mode, 5 set blower speeds are provided.
In automatic ("aut") mode, blower operation is also controlled by heater core temperature sensor. Maximum blower speed is reduced when engine coolant is cold. Maximum blower speed is increased as coolant warms. At normal engine operating temperature, all blower speeds are available.
RADIATOR COOLING FAN CONTROL
Radiator cooling fan is turned on by coolant switch when coolant temperature reaches a preset temperature. Cooling fan is also turned on by ECU when A/C compressor clutch is energized, and turned off when vehicle speed exceeds 31 MPH (50 km/h).
Heater Core Temperature Sensor
This sensor is mounted in heater case assembly and senses temperature of heated air leaving heater core. Signal is sent to ECU for automatic operation.
Ambient Temperature Sensor
This sensor is mounted in inlet air passage to blower housing and senses temperature of air entering A/C-heater assembly. Signal is sent to ECU for automatic operation
Sun Radiation Sensor
This sensor is mounted in right upper dash vent and senses amount of direct sunlight entering vehicle. Signal is sent to ECU for automatic operation.
Interior Temperature Sensor
This sensor is mounted in dome light assembly and senses temperature of in-car air. A vacuum hose is connected to sensor to force air to flow past sensor to provide accurate reading. Signal is sent to ECU for automatic operation.
Vacuum Actuators
A single vacuum actuator controls the door for defroster and floor vents, one vacuum actuator control the door for the dash vents and one vacuum actuator controls bi-level door.
Recirculation of interior air is controlled by a vacuum actuator. This occurs when mode selector dial is at maximum cooling position and interior temperature above 68°F (20°C). In this position a mixture of 85% passenger compartment air and 15% fresh air is circulated by system. (Scheme 3)
Heater Control Valve
Heater control valve is mounted on inlet coolant hose of heater core. Vacuum signals from ECU opens and closes coolant valve.
Scheme 3
FAULT CODES
ECC has self-diagnostic capability. Each time ignition is turned on, ECU performs a self-diagnostic check. Any faults detected will be deleted when key is turned off. If a fault is detected, indicator light in A/C button on control panel will flash.
As a further indication of fault, light will continue to flash after engine is started. If ECU detects a serious fault, indicator light will continue to flash until key is turned off. If fault detected is considered less serious by ECU, indicator light will flash for 20 seconds after engine start and stop flashing. See ECC FAULT CODES .
RETRIEVING FAULT CODES
Before retrieving fault codes, ensure engine has been running for 5 minutes, blower dial on automatic ("aut"), mode dial at vent, temperature dial at maximum cooling and A/C compressor operating. Direct a strong flashlight beam (not fluorescent type) at sunlight sensor.
Depress A/C button and release within 5 seconds. If fault(s) is detected by ECU, indicator light will begin flashing a 3-digit code. First number of fault code (number 1 or 2) will be displayed by one or two flashes, a pause, then second number will be displayed, a pause, then third number of fault code is displayed. Example: fault code 132 would be displayed by a single flash, a pause, 3 flashes, a pause, 2 flashes. A fault code of 111 indicates no faults have been detected.
If only one fault code is detected, indicator light will repeat that code until key is turned off. If 2 or more faults are detected, indicator light will flash each fault code in sequence and repeat cycle after last fault code is displayed.
READING FAULT CODES
Record all fault codes displayed. Turn ignition off. Refer to ECC FAULT CODES table for system fault. Repair fault. Repeat RETRIEVING FAULT CODES procedure to ensure proper repair.
| Fault Code | System Fault |
|---|---|
| 111 | No Fault |
| 121 | Ambient Temperature Sensor |
| 121 | Shorted to Ground |
| 122 | Ambient Temperature Sensor |
| 122 | Open or Shorted to 12 Volts |
| 131 | Interior Temperature Sensor |
| 131 | Shorted to Ground |
| 132 | Interior Temperature Sensor |
| 132 | Open or Shorted to 12 Volts |
| 141 (1) | Heater Core Temperature Sensor |
| 141 | Shorted to Ground |
| 142 (1) | Heater Core Temperature Sensor |
| 142 | Open or Shorted to 12 Volts |
| 151 | D+ Signal Fault in Alternator |
| 161 | Sun Radiation Sensor Fault |
| 211 | Air-Mix Motor/Potentiometer |
| 211 | Open Circuit or Shorted to Ground |
| 212 | Air-Mix Motor/Potentiometer |
| 212 | Shorted to 12 Volts |
| 213 | Air-Mix Motor Terminals No. 17 or 18 |
| 213 | Incorrectly Connected to 12 Volts |
| 214 | Air-Mix Motor Failure |
| 231 | Faulty ECU Temperature Control |
| 233 | Blower Motor Has |
| 233 | Excessive Current Draw |
| 241 (2) | Coolant Valve Vacuum Solenoid |
| 242 (2) | Bi-Level Vacuum Solenoid |
| 243 (2) | Vent Vacuum Solenoid |
| 244 (2) | Recirculation Vacuum Solenoid |
| 245 (2) | Defroster Vacuum Solenoid |
| 246 (2) | Floor Vacuum Solenoid |
| 247 (2) | Blower Maximum Speed Relay |
| 248 (2) | A/C Compressor Clutch Relay |
| 249 (2) | Electric Radiator Fan Relay |
| (1) Considered less serious fault. (2) One or more electrical connections at power unit are improperly connected or shorted to 12 volts, affecting component operation. | |
| (1) | Considered less serious fault. |
| (2) | One or more electrical connections at power unit are improperly connected or shorted to 12 volts, affecting component operation. |
ECC FAULT CODES
VACUUM CHECK
ECC system requires a minimum of 10 in. Hg vacuum to operate correctly. Check for vacuum supply to SVVA. Check vacuum supply at vacuum actuators with ECC in proper mode. See ECC VACUUM SUPPLY IDENTIFICATION.
| Vacuum Component | Hose Color | Position When Vacuum Applied |
|---|---|---|
| Coolant Valve | Gray | Open |
| Recirculation Actuator | Orange | Outside Air |
| Vent Actuator | Red | Closed |
| Bi-Level Actuator | Beige | Closed |
| Defrost Actuator | Blue | Middle Position |
| Floor Actuator | Yellow | Middle Position |
ECC VACUUM SUPPLY IDENTIFICATION
REMOVAL & INSTALLATION
Note. Information not available from manufacturer on components not covered.
- Disconnect battery negative lead. Discharge A/C system using approved refrigerant recovery/recycling equipment. Remove electrical connectors and pressure hoses from compressor (plug open hoses). Loosen mounting bolts. Remove drive belt and bolts. Lift compressor from vehicle.
- To install, reverse removal procedure. Tighten belt to specification. Recharge A/C system and check for leaks.
- Disconnect battery negative lead. Discharge A/C system using approved refrigerant recovery/recycling equipment. Remove grille and air guide at spoiler. Detach cross brace in front of condenser from upper support panel. Remove refrigerant hoses from condenser (plug open hoses). Remove condenser.
- To install, reverse removal procedure. Use new "O" rings coated with refrigerant oil. Refill A/C system and check for leaks.
Remove trim panel surrounding control panel. Remove control panel screws and pull panel out. To install, reverse removal procedure.
Removal
- Discharge A/C system (plug open hoses) using approved refrigerant recovery/recycling equipment. Disconnect evaporator connectors in engine compartment. Remove panel beneath glove compartment and remove glove compartment. (Scheme 4)
- Disconnect all electrical wires. Remove screws from lower fan housing (two screws are behind fan housing). Withdraw lower fan housing cover and lift out evaporator.
Installation
Clean sealer from lower fan housing. Transfer filter and rubber seal to new evaporator (if being replaced). Apply sealer to lower fan housing. Install evaporator in housing. Reverse removal procedure to complete installation. Refill A/C system and check for leaks.
Scheme 4
Remove panel beneath glove compartment. (Scheme 4) Remove mounting screws and remove fan motor out of housing. Disconnect wiring and remove hose for air cooling. Remove motor with fan. To install, reverse removal procedure.
- Disconnect battery negative lead. Pinch hoses to heater core from engine compartment and disconnect.
- Remove ashtray. Pull out center storage compartment in dash. Remove 2 screws behind plastic cover.
- Remove panel around gearshift lever and parking brake. Disconnect electrical plug. Remove 2 screws from bottom of storage compartment between seats. Remove center package tray.
- Remove panel and air duct below left dash. Pull floor mat down from center side panel. Remove left side panel screws.
- Remove panel beneath glove compartment and remove glove compartment. Remove glove compartment lighting. Pull floor mat down from center side panel. Remove left side panel screws.
- Remove radio and radio compartment. Remove screws holding side panels to center dash brackets. Remove side panels.
- Remove panel around control panel. Remove radio compartment console. Loosen screws holding control panel. Disconnect electrical connections at control panel and remove control panel.
- Remove all vent ducts attached to distribution unit and center panel vent. Remove vacuum hoses to vacuum actuators. Remove distribution unit from vehicle. Remove straps holding heater core to housing. Lift heater core from vehicle.
To install, reverse removal procedure. Ensure vacuum actuator hoses are installed properly. See ECC VACUUM SUPPLY IDENTIFICATION .
Disconnect battery negative lead. Discharge refrigerant system using approved refrigerant recovery/recycling equipment. Detach hoses from receiver-drier (plug open hoses). Disconnect electrical connector. Remove from mounting bracket.
Transfer pressure sensor to new receiver-drier (if necessary). To install, reverse removal procedure.
- To remove the recirculation vacuum actuator, remove panel beneath glove compartment and remove glove compartment. Remove outer panel vents and air ducts. Disconnect vacuum hose and control rod from vacuum actuator.
- To remove the vent actuator or defroster actuator motors, remove heater core distribution unit. To install, reverse removal procedure.
Scheme 5
Automatic A/C-Heater Wiring Diagram. Scheme 6
See also:
• ECC FAULT CODES