Lexus IS250 · Service Manual HEATER & AIR CONDITIONING SYSTEM

TERMINALS OF ECU

System information


AIR CONDITIONING AMPLIFIER
E103240E06

HINT:
Check from the rear of the connector while it is connected to the A/C amplifier.

Symbols (Terminal No.)
 Wiring Color
 Terminal Description
 Condition
 Specified Condition
J58-1 (B) - J58-20 (GND)
 Y - W-B
 Power source (Back-up)
 Always
 10 to 14 V
J58-2 (MHTR) - J58-20 (GND)
 BR - W-B
 MIR/HTR relay signal
 Engine switch on (IG), REAR DEF switch: OFF
 10 to 14 V
J58-2 (MHTR) - J58-20 (GND)
 BR - W-B
 MIR/HTR relay signal
 Engine switch on (IG), REAR DEF switch: ON
 Below 1 V
J58-3 (RDEF) - J58-20 (GND)
 B - W-B
 DEFOG relay signal
 Engine switch on (IG), FRONT DEF switch: OFF
 10 to 14 V
J58-3 (RDEF) - J58-20 (GND)
 B - W-B
 DEFOG relay signal
 Engine switch on (IG), FRONT DEF switch: ON
 Below 1 V
J58-4 (HTR2) - J58-20 (GND)
 LG - W-B
 GLW RLY2 relay signal
 Engine switch on (IG)
 10 to 14 V
J58-4 (HTR2) - J58-20 (GND)
 LG - W-B
 GLW RLY2 relay signal
 Engine switch on (IG)
Engine running at 850 rpm or more, Ambient temperature 0°C (32°F) or less, Engine coolant temperature 69°C (156°F) or less, Temperature switch: MAX HOT, Blower switch: LO
 Below 1 V
J58-5 (SOL+) - J58-20 (GND)
 G - W-B
 A/C compressor operation signal
 A/C switch: ON
 Pulse generation
(See waveform 1)
J58-11 (BLW) - J58-20 (GND)
 O - W-B
 Blower motor speed control signal
 Engine switch on (IG), Blower switch: ON
 Pulse generation
(See waveform 2)
J58-13 (PRE) - J58-38 (SG-2)
 V - P
 Pressure sensor signal
 Start engine, Operate A/C system, Refrigerant pressure: Abnormal pressure (more than 3,030 kPa (31.0 kgf/cm, 440 psi))
 4.7 V or higher
J58-13 (PRE) - J58-38 (SG-2)
 V - P
 Pressure sensor signal
 Start engine, Operate A/C system, Refrigerant pressure: Abnormal pressure (less than 180 kPa (1.9 kgf/cm, 27 psi))
Below 0.7 V
J58-13 (PRE) - J58-38 (SG-2)
 V - P
 Pressure sensor signal
 Start engine, Operate A/C system, Refrigerant pressure: Abnormal pressure (more than 3,030 kPa (31.0 kgf/cm, 440 psi) and less than 180 kPa (1.9 kgf/cm, 27 psi))
 0.7 to 4.7 V
J58-14 (TSP) - J58-20 (GND)
 P - W-B
 Passenger side solar sensor signal
 Engine switch on (IG), Solar sensor subjected to electric light
 0.8 to 4.3 V
J58-14 (TSP) - J58-20 (GND)
 P - W-B
 Passenger side solar sensor signal
 Engine switch on (IG), Solar sensor is covered with a cloth
 Below 0.8 V
J58-16 (TR) - J58-19 (SG-1)
 G - L
 Room temperature sensor signal
 Engine switch on (IG), Cabin temperature: 25°C (77°F)
 1.6 to 1.8 V
J58-16 (TR) - J58-19 (SG-1)
 G - L
 Room temperature sensor signal
 Engine switch on (IG), Cabin temperature: 40°C (104°F)
 0.8 to 1.0 V
J58-19 (SG-1) - Body ground
 L - Body ground
 Ground for room temperature sensor
 Always
 Below 1 V
J58-20 (GND) - Body ground
 W-B - Body ground
 Ground for main power supply
 Always
 Below 1 V
J58-21 (IG+) - J58-20 (GND)
 B - W-B
 Power source (IG)
 Engine switch on (IG)
 10 to 14 V
J58-21 (IG+) - J58-20 (GND)
 B - W-B
 Power source (IG)
 Engine switch off
 Below 1 V
J58-23 (HTR1) - J58-20 (GND)
 L - W-B
 GLW RLY1 relay signal
 Engine switch on (IG)
 10 to 14 V
J58-23 (HTR1) - J58-20 (GND)
 L - W-B
 GLW RLY1 relay signal
 Engine switch on (IG)
Engine running at 850 rpm or more, Ambient temperature 0°C (32°F) or less, Engine coolant temperature 69°C (156°F) or less, Temperature switch: MAX HOT, blower switch: LO
 Below 1 V
J58-26 (S5-2) - J58-38 (SG-2)
 W - P
 Power supply for pressure sensor
 Engine switch on (IG), A/C switch: ON
 5 V
J58-26 (S5-2) - J58-38 (SG-2)
 W - P
 Power supply for pressure sensor
 Engine switch on (IG), A/C switch: OFF
 Below 1 V
J58-30 (MPX+) - J58-31 (MPX-)
 BR - BR
 Multiplex communication system
 Multiplex communication circuit
 -
J58-33 (DGS1) - J58-39 (SG-6)
 R - Y
 Exhaust gas sensor signal (Nox)
 After 30 seconds from engine switch on (IG) and sensor is exposed to exhaust gas
 1.0 to 4.5 V
J58-34 (DGS) - J58-39 (SG-6)
 BR - Y
 Exhaust gas sensor signal (HC, CO)
 After 30 seconds from engine switch on (IG) and sensor is exposed to exhaust gas
 1.0 to 4.5 V
J58-35 (TSD) - J58-20 (GND)
 LG - W-B
 Driver side solar sensor signal
 Engine switch on (IG), Solar sensor subjected to electric light
 0.8 to 4.3 V
J58-35 (TSD) - J58-20 (GND)
 LG - W-B
 Driver side solar sensor signal
 Engine switch on (IG), Solar sensor is covered with a cloth
 Below 0.8 V
J58-38 (SG-2) - Body ground
 P - Body ground
 Ground for pressure sensor
 Always
 Below 1 V
J58-39 (SG-6) - Body ground
 Y - Body ground
 Ground for exhaust gas sensor
 Always
 Below 1 V
e1- 2 (BUS G) - Body ground
 -
 Ground for BUS IC
 Always
 Below 1 V
e1- 3 (BUS) - e1-2 (BUS G)
 -
 BUS IC control signal
 Engine switch off → on (IG)
 Pulse generation
e1-4 (B BUS) - e1-2 (BUS G)
 -
 Power supply for BUS IC
 Engine switch on (IG)
 10 to 14 V
e1-4 (B BUS) - e1-2 (BUS G)
 -
 Power supply for BUS IC
 Engine switch off
 Below 1 V
e1-6 (TE) - e1-5 (SG)
 -
 Evaporator temperature sensor signal
 Engine switch on (IG), Evaporator temperature 0°C (32°F)
 2.0 to 2.4 V
e1-6 (TE) - e1-5 (SG)
 -
 Evaporator temperature sensor signal
 Engine switch on (IG), Evaporator temperature 15°C (59°F)
 1.4 to 1.8 V

  1. E106664E02
    Waveform 1:
    Item
    		 Contents
    Terminal No.
    (Symbols)
    		 J58-5 (SOL+) - J58-20 (GND)
    Tool Setting
    		 5 V/DIV.,
    500 μs/DIV.
    Vehicle Condition
    		 Engine switch on (IG)
    A/C switch: ON

  2. E103396E01
    Waveform 2:
    Item
    		 Contents
    Terminal No.
    (Symbols)
    		 J58-5 (SOL+) - J58-20 (GND)
    Tool Setting
    		 1 V/DIV.,
    500 μs/DIV.
    Vehicle Condition
    		 Engine switch on (IG)
    Blower switch: ON


MULTI-DISPLAY (w/ NAVIGATION SYSTEM)
E116934E01
Symbols (Terminal No.)
 Wiring Color
 Terminal Description
 Condition
 Specified Condition
J54-3 (GND1) - Body ground
 W-B - Body ground
 Ground for heater control panel
 Always
 Below 1 V
J54-10 (IG) - J54-3 (GND1)
 B - W-B
 Power source (IG)
 Engine switch on (IG)
 10 to 14 V
J54-10 (IG) - J54-3 (GND1)
 B - W-B
 Power source (IG)
 Engine switch off
 Below 1 V
J54-11 (ACC) - J54-3 (GND1)
 O - W-B
 Power source (ACC)
 Engine switch on (ACC)
 10 to 14 V
J54-11 (ACC) - J54-3 (GND1)
 O - W-B
 Power source (ACC)
 Engine switch off
 Below 1 V
J54-12 (+B1) - J54-3 (GND1)
 LG - W-B
 Power source (Back-up)
 Always
 10 to 14 V

INTEGRATION CONTROL & PANEL ASSEMBLY (w/o NAVIGATION SYSTEM)
E116935E01
Symbols (Terminal No.)
 Wiring Color
 Terminal Description
 Condition
 Specified Condition
J53-4 (IG+) - J53-8 (E)
 B - W-B
 Power source (IG)
 Engine switch on (IG)
 10 to 14 V
J53-4 (IG+) - J53-8 (E)
 B - W-B
 Power source (IG)
 Engine switch off
 Below 1 V
J53-5 (ACC) - J53-8 (E)
 O - W-B
 Power source (ACC)
 Engine switch on (ACC)
 10 to 14 V
J53-5 (ACC) - J53-8 (E)
 O - W-B
 Power source (ACC)
 Engine switch off
 Below 1 V
J53-8 (E) - Body ground
 W-B - Body ground
 Ground for heater control panel
 Always
 Below 1 V
J53-14 (B) - J53-8 (E)
 LG - W-B
 Power source (Back-up)
 Always
 10 to 14 V

ECM
A103802E12
Symbols (Terminal No.)
 Wiring Color
 Terminal Description
 Condition
 Specified Condition
E3-10 (LCKI) - E4-7 (E1)
 B - BR
 Compressor lock sensor signal
 Engine idling, Blower switch: LO, A/C switch: ON
 Pulse generation
(See waveform 3)
E4-7 (E1) - Body ground
 BR - Body ground
 Ground for ECM
 Always
 Below 1 V
E5-30 (E3) - Body ground
 BR - Body ground
 Ground for ambient temperature sensor
 Always
 Below 1 V
A6-13 (ACMG) - E4-7 (E1)
 L - BR
 Compressor operation signal
 Engine idling, Blower switch: LO, A/C switch: OFF
 10 to 14 V
A6-13 (ACMG) - E4-7 (E1)
 L - BR
 Compressor operation signal
 Engine idling, Blower switch: LO, A/C switch: ON
 Below 1 V
A5-18 (TAM) - E5-30 (E3)
 V-R - BR
 Ambient temperature sensor signal
 Engine switch on (IG) at 25°C (77°F)
 1.8 to 2.2 V
A5-18 (TAM) - E5-30 (E3)
 V-R - BR
 Ambient temperature sensor signal
 Engine switch on (IG) at 40°C (104°F)
 1.2 to 1.6 V

  1. E116941E01
    Waveform 3:
    Item
    		 Contents
    Terminal No.
    (Symbols)
    		 E3-10 (LCKI) - E4-7 (E1)
    Tool Setting
    		 200 mV/DIV.,
    10 ms/DIV.
    Vehicle Condition
    		 Engine switch on (IG)
    Blower switch: LO
    A/C switch: ON

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