1986 TOYOTA SUPRA air condition

IDLE AND OR 2500 RPM CO HC CHECK
HINT: This check is used only to determine whether or not the
idle CO/HC complies with regulations.
1. INITIAL CONDITIONS
(a) Engine at normal operating temperature
(b) Air cleaner installed
(c) All pipes and hoses of air induction system connected
(d) All accessories switched OFF
(e) All vacuum lines properly connected
HINT: All vacuum hoses for EGR system, etc. should be prop-
erly connected.
(f) SFI system wiring connectors fully plugged
(g) Ignition timing set correctly
(h) Transmission in neutral position
(i) Tachometer and CO/HC meter calibrated by hand
2. START ENGINE
3. RACE ENGINE AT 2,500 RPM FOR APPROX. 180
SECONDS
4. INSERT CO/HC METER TESTING PROBE AT LEAST 40
cm (1.3 ft) INTO TAILPIPE DURING IDLING
5. IMMEDIATELY CHECK CO/HC CONCENTRATION AT
IDLE AND/OR 2,500 RPM
HINT: When performing the 2 mode (2,500 rpm and idle) test,
follow the measurement order prescribed by the applicable
local regulations.
± ENGINEENGINE MECHANICALEG±7

(d) Using a timing light, check the ignition timing.
Ignition timing:
10 + 25 BTDC @ idle
(Transmission in neutral position)
If the ignition timing is not as specified, check the valve tim-
ing. (See step 14 in timing belt installation)
(e) Remove the SST from the DLC1.
SST 09843±18020
5. FURTHER CHECK IGNITION TIMING
Ignition timing:
10±205 BTDC @ idle
(Transmission in neutral position)
HINT: The timing mark moves in a range between 10° and
20°.
6. DISCONNECT TACHOMETER AND TIMING LIGHT
IDLE SPEED INSPECTION
1. INITIAL CONDITIONS
(a) Engine at normal operating temperature
(b) Air cleaner installed
(c) All pipes and hoses of air induction system connected
(d) All accessories switched OFF
(e) All vacuum lines properly connected
HINT: All vacuum hoses for EGR system, etc. should be prop-
erly connected.
(f) SFI system wiring connectors fully plugged
(g) Ignition timing set correctly
(h) Transmission in neutral position
2. CONNECT TACHOMETER
(See step 2 in ignition timing inspection and adjustment
(2JZ±GE))
3. INSPECT IDLE SPEED
(a) Race the engine speed at 2,500 rpm for approx. 90 seconds.
(b) Check the idle speed.
Idle speed:
2JZ±GE
700 + 50 rpm
2JZ±GTE
650 + 50 rpm
If the idle speed is not as specified, check the IAC valve. (See
on±vehicle inspection in ISC valve in SFI System)
4. DISCONNECT TACHOMETER
± ENGINEENGINE MECHANICALEG±21

15
TROUBLESHOOTING / ABBREVIATIONS
DISCONNECTION AND CONNECTION OF BOLT
TYPE CONNECTORS
For engine control module (engine and electronically controlled
transmission ECU) in this vehicle, connectors are used which
require a bolt built into the connector to be screwed down to
securely connect the connector.
1. Disconnect the connector
After completely loosening the bolt, the two parts of the
connector can be separated.
NOTICE:
Do not pull the wire harness when disconnecting the
connector.
2. Connect the connector
NOTICE:
Before connecting the connector, always check that the
terminals are not bent or damaged.
(a) Match the guide section of the male connector
correctly with the female connector, then press them
together.
(b) Tighten the bolt.
Make sure the connectors are completely connected,
by tightening the bolt until there is a clearance of less
than 1 mm (0.04 in.) between the bottom of male
connector and the end of female connector.
ABBREVIATIONS
The following abbreviations are used in this manual.
ABS = Anti±Lock Brake System O/D = Overdrive
A/C = Air Conditioning PPS = Progressive Power Steering
ACIS = Acoustic Control Induction System R/B = Relay Block
A/T = Automatic Transmission RH = Right±Hand
COMB. = Combination SFI = Sequential Multiport Fuel Injection
ECU = Electronic Control Unit SRS = Supplemental Restraint System
EFI = Electronic Fuel Injection SW = Switch
EGR = Exhaust Gas Recirculation TDCL = Total Diagnostic Communication Link
EVAP = Evaporative Emission TEMP. = Temperature
ISC = Idle Speed Control TRAC = Traction Control System
J/B = Junction Block VSV = Vacuum Switching Valve
LH = Left-Hand w/ = With
M/T = Manual Transmission w/o = Without
* The titles given inside the components are the names of the terminals (terminal codes) and are not treated
as being abbreviations.

15
ABBREVIATIONS
DISCONNECTION AND CONNECTION OF BOLT
TYPE CONNECTORS
For engine control module (engine and electronically controlled
transmission ECU) in this vehicle, connectors are used which
require a bolt built into the connector to be screwed down to
securely connect the connector.
1. Disconnect the connector
After completely loosening the bolt, the two parts of the
connector can be separated.
NOTICE:
Do not pull the wire harness when disconnecting the
connector.
2. Connect the connector
NOTICE:
Before connecting the connector, always check that the
terminals are not bent or damaged.
(a) Match the guide section of the male connector
correctly with the female connector, then press them
together.
(b) Tighten the bolt.
Make sure the connectors are completely connected,
by tightening the bolt until there is a clearance of less
than 1 mm (0.04 in.) between the bottom of male
connector and the end of female connector.
ABBREVIATIONS
The following abbreviations are used in this manual.
ABS = Anti±Lock Brake System O/D = Overdrive
A/C = Air Conditioning PPS = Progressive Power Steering
ACIS = Acoustic Control Induction System R/B = Relay Block
A/T = Automatic Transmission RH = Right±Hand
COMB. = Combination SFI = Sequential Multiport Fuel Injection
ECU = Electronic Control Unit SRS = Supplemental Restraint System
EFI = Electronic Fuel Injection SW = Switch
EGR = Exhaust Gas Recirculation TDCL = Total Diagnostic Communication Link
EVAP = Evaporative Emission TEMP. = Temperature
ISC = Idle Speed Control TRAC = Traction Control System
J/B = Junction Block VSV = Vacuum Switching Valve
LH = Left-Hand w/ = With
M/T = Manual Transmission w/o = Without
* The titles given inside the components are the names of the terminals (terminal codes) and are not treated
as being abbreviations.

71
2. CONTROL SYSTEM
*SEQUENTIAL MULTIPORT FUEL INJECTION (ELECTRONIC FUEL INJECTION) SYSTEM
THE SEQUENTIAL MULTIPORT FUEL INJECTION (ELECTRONIC FUEL INJECTION) SYSTEM MONITORS THE ENGINE CONDITION
THROUGH THE SIGNALS INPUT FROM EACH SENSOR (INPUT SIGNALS FROM (1) TO (13) ETC.) TO THE ENGINE CONTROL
MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU). THE BEST FUEL INJECTION TIMING IS DECIDED
BASED ON THIS DATA AND THE PROGRAM MEMORIZED BY THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU), AND THE CONTROL SIGNAL IS OUTPUT TO TERMINALS #10, #20, #30, 40, #50 AND #60 OF
THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) TO OPERATE THE
INJECTOR (INJECT THE FUEL). THE SEQUENTIAL MULTIPORT FUEL INJECTION (ELECTRONIC FUEL INJECTION) SYSTEM
PRODUCES CONTROLS OF FUEL INJECTION OPERATION BY THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) IN RESPONSE TO THE DRIVING CONDITIONS.
*ESA (ELECTRONIC SPARK ADVANCE) SYSTEM
THE ESA SYSTEM MONITORS THE ENGINE CONDITION THROUGH THE SIGNALS INPUT TO THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) FROM EACH SENSOR (INPUT SIGNALS FROM (1), (2), (4) TO
(13) ETC.). THE BEST IGNITION TIMING IS DECIDED ACCORDING TO THIS DATA AND THE MEMORIZED DATA IN THE ENGINE
CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AND THE CONTROL SIGNAL IS OUTPUT
TO TERMINALS IGT1, IGT2, IGT3, IGT4, IGT5 AND IGT6 THESE SIGNALS CONTROL THE IGNITER TO PROVIDE THE BEST IGNITION
TIMING FOR THE DRIVING CONDITIONS.
*HEATED OXYGEN SENSOR HEATER CONTROL SYSTEM
THE MAIN HEATED OXYGEN SENSOR, SUB HEATED OXYGEN SENSOR HEATER CONTROL SYSTEM TURNS THE HEATER ON
WHEN THE INTAKE AIR VOLUME IS LOW (TEMP. OF EXHAUST EMISSIONS IS LOW), AND WARMS UP THE OXYGEN SENSOR TO
IMPROVE DETECTION PERFORMANCE OF THE SENSOR. THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) EVALUATES THE SIGNALS FROM EACH SENSOR (INPUT SIGNALS FROM (1), (2), (4), (9) TO
(11) ETC.), AND OUTPUTS CURRENT TO TERMINALS HT1, HT2 TO CONTROL THE HEATER.
*IDLE AIR CONTROL (IDLE SPEED CONTROL) SYSTEM
THE IDLE AIR CONTROL (ISC) SYSTEM (STEP MOTOR TYPE) INCREASES THE ENGINE SPEED AND PROVIDES IDLING STABILITY
FOR FAST IDLE±UP WHEN THE ENGINE IS COLD, AND WHEN THE IDLE SPEED HAS DROPPED DUE TO ELECTRICAL LOAD AND SO
ON. THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) EVALUATE THE
SIGNALS FROM EACH SENSOR (INPUT SIGNALS FROM (1), (4), (5), (8), (9), (11) ETC.), OUTPUTS CURRENT TO TERMINALS ISC1,
ISC2, ISC3 AND ISC4 TO CONTROL THE IDLE AIR CONTROL VALVE (ISC VALVE).
*EGR CONTROL SYSTEM
THE EGR CONTROL SYSTEM DETECTS THE SIGNAL FROM EACH SENSOR (INPUT SIGNALS FROM (1), (4), (9), (10) ETC.), AND
OUTPUTS CURRENT TO TERMINAL EGR TO CONTROL THE EGR VALVE.
*FUEL PUMP CONTROL SYSTEM
THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) OUTPUTS CURRENT TO
TERMINAL FPC AND CONTROLS THE FUEL PUMP ECU AND FUEL PUMP DRIVE SPEED IN RESPONSE TO THE DRIVING
CONDITIONS.
3. DIAGNOSIS SYSTEM
WITH THE DIAGNOSIS SYSTEM, WHEN THERE IS A MALFUNCTION IN THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU) SIGNAL SYSTEM, THE MALFUNCTIONING SYSTEM IS RECORDED IN THE
MEMORY. THE MALFUNCTIONING SYSTEM CAN BE FOUND BY READING THE CODE DISPLAYED BY THE MALFUNCTION INDICATOR
LAMP (CHECK ENGINE WARNING LIGHT).
4. FAIL±SAFE SYSTEM
WHEN A MALFUNCTION HAS OCCURRED IN ANY SYSTEM, IF THERE IS A POSSIBILITY OF ENGINE TROUBLE BEING CAUSED BY
CONTINUED CONTROL BASED ON THE SIGNALS FROM THAT SYSTEM, THE FAIL±SAFE SYSTEM EITHER CONTROLS THE SYSTEM
BY USING DATA (STANDARD VALUES) RECORDED IN THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) MEMORY OR ELSE STOPS THE ENGINE.

83
(13) ENGINE KNOCK SIGNAL CIRCUIT
ENGINE KNOCKING IS DETECTED BY KNOCK SENSOR FRONT AND REAR SIDE AND THE SIGNAL IS INPUT INTO TERMINALS
KNK1 AND KNK2 AS A CONTROL SIGNAL.
2. CONTROL SYSTEM
*SEQUENTIAL MULTIPORT FUEL INJECTION (ELECTRONIC FUEL INJECTION) SYSTEM
THE SEQUENTIAL MULTIPORT FUEL INJECTION (ELECTRONIC FUEL INJECTION) SYSTEM MONITORS THE ENGINE CONDITION
THROUGH THE SIGNALS INPUT FROM EACH SENSOR (INPUT SIGNALS FROM (1) TO (13) ETC.) TO THE ENGINE CONTROL
MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU). THE BEST FUEL INJECTION TIMING IS DECIDED
BASED ON THIS DATA AND THE PROGRAM MEMORIZED BY THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU), AND THE CONTROL SIGNAL IS OUTPUT TO TERMINALS #10, #20, #30, 40, #50 AND #60 OF
THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) TO OPERATE THE
INJECTOR (INJECT THE FUEL). THE SEQUENTIAL MULTIPORT FUEL INJECTION (ELECTRONIC FUEL INJECTION) SYSTEM
PRODUCES CONTROLS OF FUEL INJECTION OPERATION BY THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) IN RESPONSE TO THE DRIVING CONDITIONS.
*ESA (ELECTRONIC SPARK ADVANCE) SYSTEM
THE ESA SYSTEM MONITORS THE ENGINE CONDITION THROUGH THE SIGNALS INPUT TO THE ENGINE CONTROL MODULE
(ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) FROM EACH SENSOR (INPUT SIGNALS FROM (1), (2), (4) TO
(13) ETC.). THE BEST IGNITION TIMING IS DECIDED ACCORDING TO THIS DATA AND THE MEMORIZED DATA IN THE ENGINE
CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) AND THE CONTROL SIGNAL IS OUTPUT
TO TERMINAL IGT. THIS SIGNAL CONTROLS THE IGNITER TO PROVIDE THE BEST IGNITION TIMING FOR THE DRIVING
CONDITIONS.
*HEATED OXYGEN SENSOR HEATER CONTROL SYSTEM (FOR CALIFORNIA)
THE MAIN HEATED OXYGEN SENSOR FRONT AND REAR SIDE, SUB HEATED OXYGEN SENSOR HEATER CONTROL SYSTEM
TURNS THE HEATER ON WHEN THE INTAKE AIR VOLUME IS LOW (TEMP. OF EXHAUST EMISSIONS IS LOW), AND WARMS UP THE
OXYGEN SENSOR TO IMPROVE DETECTION PERFORMANCE OF THE SENSOR. THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU) EVALUATES THE SIGNALS FROM EACH SENSOR (INPUT SIGNALS FROM
(1), (2), (4), (9) TO (11) ETC.), AND OUTPUTS CURRENT TO TERMINALS HT1, HT2, HT3 TO CONTROL THE HEATER.
*IDLE AIR CONTROL (IDLE SPEED CONTROL) SYSTEM
THE IDLE AIR CONTROL (ISC) SYSTEM (STEP MOTOR TYPE) INCREASES THE ENGINE SPEED AND PROVIDES IDLING STABILITY
FOR FAST IDLE±UP WHEN THE ENGINE IS COLD, AND WHEN THE IDLE SPEED HAS DROPPED DUE TO ELECTRICAL LOAD AND SO
ON. THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) EVALUATES THE
SIGNALS FROM EACH SENSOR (INPUT SIGNALS FROM (1), (4), (5), (8), (9), (11) ETC.), OUTPUTS CURRENT TO TERMINALS ISC1,
ISC2, ISC3 AND ISC4 TO CONTROL THE IDLE AIR CONTROL VALVE (ISC VALVE).
*EGR CONTROL SYSTEM
THE EGR CONTROL SYSTEM DETECTS THE SIGNAL FROM EACH SENSOR (INPUT SIGNALS FROM (1), (4), (9), (10) ETC.), AND
OUTPUTS CURRENT TO TERMINAL EGR TO CONTROL THE EGR VALVE.
*FUEL PUMP CONTROL SYSTEM
THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) OUTPUTS CURRENT TO
TERMINAL FPC AND CONTROLS THE FUEL PUMP ECU AND FUEL PUMP DRIVE SPEED IN RESPONSE TO THE DRIVING
CONDITIONS.
*ACIS (ACOUSTIC CONTROL INDUCTION SYSTEM)
ACIS INCLUDES A VALVE IN THE BULKHEAD SEPARATING THE SURGE TANK INTO TWO PARTS. THIS VALVE IS OPENED AND
CLOSED IN ACCORDANCE WITH THE DRIVING CONDITIONS TO CONTROL THE INTAKE MANIFOLD LENGTH IN TWO STAGES FOR
INCREASED ENGINE OUTPUT IN ALL RANGES FROM LOW TO HIGH SPEEDS.
THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY CONTROLLED TRANSMISSION ECU) JUDGES THE VEHICLE
SPEED BY THE SIGNALS ((4), (5)) FROM EACH SENSOR AND OUTPUTS SIGNALS TO THE TERMINAL ACIS TO CONTROL THE VSV
(FOR INTAKE CONTROL VALVE).
3. DIAGNOSIS SYSTEM
WITH THE DIAGNOSIS SYSTEM, WHEN THERE IS A MALFUNCTION IN THE ENGINE CONTROL MODULE (ENGINE AND
ELECTRONICALLY CONTROLLED TRANSMISSION ECU) SIGNAL SYSTEM, THE MALFUNCTIONING SYSTEM IS RECORDED IN THE
MEMORY. THE MALFUNCTIONING SYSTEM CAN BE FOUND BY READING THE CODE DISPLAYED BY THE MALFUNCTION INDICATOR
LAMP (CHECK ENGINE WARNING LIGHT).
4. FAIL±SAFE SYSTEM
WHEN A MALFUNCTION HAS OCCURRED IN ANY SYSTEM, IF THERE IS A POSSIBILITY OF ENGINE TROUBLE BEING CAUSED BY
CONTINUED CONTROL BASED ON THE SIGNALS FROM THAT SYSTEM, THE FAIL±SAFE SYSTEM EITHER CONTROLS THE SYSTEM
BY USING DATA (STANDARD VALUES) RECORDED IN THE ENGINE CONTROL MODULE (ENGINE AND ELECTRONICALLY
CONTROLLED TRANSMISSION ECU) MEMORY OR ELSE STOPS THE ENGINE.

228
RADIATOR FAN AND AUTOMATIC AIR CONDITIONING
1. HEATER BLOWER OPERATION
MANNAL BLOWER OPERATION
WHEN THE BLOWER CONTROL SW IS SET TO ANY BLOWER SPEEDS, THE A/C AMPLIFIER OPERATES AND THE CURRENT TO DRIVE
THE BLOWER MOTOR FLOWS FROM TERMINAL BLW OF THE A/C AMPLIFIER TO TERMINAL SI OF THE BLOWER MOTOR CONTROL
RELAY. THE CURRENT ACTIVATES THE RELAY AND THE VOLTAGE APPLIED TO TERMINAL +B OF THE BLOWER MOTOR CONTROL
RELAY IS OUTPUT AT TERMINAL M+ AS THE VOLTAGE FOR THE SELECTED BLOWER SPEED. THE CURRENT THEN FLOWS FROM
TERMINAL M+ OF THE BLOWER MOTOR CONTROL RELAY TO TERMINAL 2 " TERMINAL 1 " TERMINAL M± OF BLOWER MOTOR
CONTROL RELAY " TERMINAL GND " GROUND, AND THE BLOWER MOTOR OPERATES AT THE BLOWER SPEED SELECTED.
AUTO FUNCTION
WHEN THE AUTO SW IS TURNED ON, THE A/C AMPLIFIER CALCULATES THE REQUIRED VENT TEMPERATURE BASED ON THE SET
TEMPERATURE AND INPUT FROM EACH SENSOR. THEN TERMINAL BLW OF THE A/C AMPLIFIER INPUTS CURRENT TO TERMINAL SI
OF THE BLOWER MOTOR CONTROL RELAY IN CONFORMITY WITH THE REQUIRED VENT OUTPUT. THIS CURRENT ACTIVATES THE
BLOWER MOTOR CONTROL RELAY SO THAT CURRENT FLOWS FROM TERMINAL M+ OF THE BLOWER MOTOR CONTROL RELAY "
TERMINAL 2 OF BLOWER MOTOR " TERMINAL 1 " TERMINAL M± OF BLOWER MOTOR CONTROL RELAY " TERMINAL GND "
GROUND, ACTIVATING THE BLOWER MOTOR. THE BLOWER MOTOR THEN OPERATES AT DIFFERENT STEPS IN CONFORMITY WITH
VARIABLE CURRENT FLOW OUTPUT FROM TERMINAL BLW OF THE A/C AMPLIFIER TO TERMINAL SI OF THE BLOWER MOTOR
CONTROL RELAY.
2. OPERATION OF AIR INLET CONTROL SERVO MOTOR
(SWITCHING FROM FRESH TO RECIRC)
WITH IGNITION SW TURNED ON, THE CURRENT FLOWS FROM HTR FUSE TO TERMINAL 2 OF AIR INLET CONTROL SERVO MOTOR
" TERMINAL 5 " TERMINAL AIR OF A/C AMPLIFIER " TERMINAL GND " GROUND, THE MOTOR ROTATES AND THE DAMPER
STOPS AT RECIRC POSITION.
(SWITCH(NG FROM RECIRC TO FRESH)
WITH IGNITION SW TURNED ON, THE CURRENT FLOWS FROM HTR FUSE TO TERMINAL 2 OF AIR INLET CONTROL SERVO MOTOR
" TERMINAL 3 " TERMINAL AIF OF A/C AMPLIFIER " TERMINAL GND " GROUND, THE MOTOR ROTATES AND THE DAMPER
STOPS AT FRESH POSITION.
3. OPERATION OF AIR VENT MODE CONTROL SERVO MOTOR
WITH IGNITION SW TURNED ON, THE CURRENT FLOWS FROM HTR FUSE TO TERMINAL IG OF A/C AMPLIFIER
(SWITCHING FROM DEF TO FACE)
THE CURRENT FROM TERMINAL AOF OF A/C AMPLIFIER " TERMINAL 1 OF AIR VENT MODE CONTROL SERVO MOTOR "
TERMINAL 2 " TERMINAL AOD OF A/C AMPLIFIER " TERMINAL GND " GROUND. THE MOTOR ROTATES AND THE DAMPER
MOVES TO FACE SIDE. WHEN THE DAMPER OPERATES WITH THE A/C SW AT FACE POSITION, THE DAMPER POSITION SIGNAL IS
INPUT FROM TERMINAL 3 OF THE SERVO MOTOR TO THE TERMINAL TPO OF THE A/C AMPLIFIER. AS A RESULT, CURRENT TO THE
SERVO MOTOR CIRCUIT IS CUT OFF BY THE AMPLIFIER, SO THE DAMPER STOPS AT THAT POSITION.
(SWITCHING FROM FACE TO DEF)
THE CURRENT FLOWS FROM TERMINAL AOD OF A/C AMPLIFIER " TERMINAL 2 OF AIR VENT MODE CONTROL SERVO MOTOR "
TERMINAL 1 " TERMINAL AOF OF A/C AMPLIFIER " TERMINAL GND " GROUND, THE MOTOR ROTATES AND THE DAMPER STOPS
AT THAT POSITION.
4. OPERATION OF AIR MIX CONTROL SERVO MOTOR
WHEN THE TEMPERATURE SW IS TURNED TO THE ªCOOLº SIDE, THE CURRENT FLOWS FROM TERMINAL AMC OF A/C AMPLIFIER
" TERMINAL 1 OF AIR MIX CONTROL SERVO MOTOR " MOTOR " TERMINAL 2 " TERMINAL AMH OF A/C AMPLIFIER " TERMINAL
GND " GROUND AND THE MOTOR ROTATES. THE DAMPER OPENING ANGLE AT THIS TIME IS INPUT FROM TERMINAL 3 OF SERVO
MOTOR TO TERMINAL TP OF A/C CONTROL ASSEMBLY, THIS IS USED TO DETERMINE THE DAMPER STOP POSITION AND MAINTAIN
THE SET TEMPERATURE.
WHEN THE TEMPERATURE CONTROL SW IS TURNED TO THE ªWARMº SIDE, THE CURRENT FLOWS FROM TERMINAL AMH OF A/C
AMPLIFIER " TERMINAL 2 OF AIR MIX CONTROL SERVO MOTOR " MOTOR " TERMINAL 1 " TERMINAL AM1 OF A/C AMPLIFIER,
ROTATING THE MOTOR IN REVERSE AND SWITCHING THE DAMPER FROM COOL TO WARM SIDE.
SYSTEM OUTLINE

229
5. AIR CONDITIONING OPERATION
THE A/C AMPLIFIER RECEIVES VARIOUS SIGNALS, I.E., THE ENGINE RPM FROM THE IGNITER, OUTLET TEMPERATURE SIGNAL
FROM THE A/C THERMISTOR, COOLANT TEMPERATURE FROM THE ENGINE COOLANT TEMP. SENSOR (EFI WATER TEMP. SENSOR)
AND THE LOCK SIGNAL FROM THE A/C COMPRESSOR, ETC.
WHEN THE ENGINE IS STARTED AND THE A/C SW (HEATER CONTROL SW) IS ON, A SIGNAL IS INPUT TO THE A/C AMPLIFIER. AS A
RESULT, THE GROUND CIRCUIT IN A/C AMPLIFIER IS CLOSED AND CURRENT FLOWS FROM HTR FUSE TO TERMINAL 1 OF A/C
MAGNETIC CLUTCH RELAY " TERMINAL 2 " TERMINAL ACMG OF ENGINE CONTROL MODULE (ENGINE ECU) " TERMINAL A/C "
TERMINAL MGC OF A/C AMPLIFIER " TERMINAL GND " GROUND, TURNING THE RELAY ON, SO THAT THE A/C MAGNETIC CLUTCH
IS ON AND THE A/C AMPLIFIER OPERATES.
AT THE SAME TIME, THE ENGINE CONTROL MODULE (ENGINE ECU) DETECTS THE MAGNETIC CLUTCH IS ON AND THE A/C
AMPLIFIER IS OPERATING AND OPENS DIRECTION TO AVOID LOWERING THE ENGINE RPM DURING A/C OPERATING.
WHEN ANY OF THE FOLLOWING SIGNALS ARE INPUT TO THE A/C AMPLIFIER, THE A/C AMPLIFIER OPERATES TO TURN OFF THE
AIR CONDITIONING.
*ENGINE RPM SIGNAL IS HIGH.
*COOLANT TEMP. SIGNAL IS HIGH.
*A SIGNAL THAT THE TEMPERATURE AT THE AIR OUTLET IS LOW.
*A SIGNAL THAT THERE IS A LARGE DIFFERENCE BETWEEN ENGINE SPEED AND COMPRESSOR SPEED.
*A SIGNAL THAT THE REFRIGERANT PRESSURE IS ABNORMALLY HIGH OR LOW.