Terminals Of Ecu

WARNING: This page is about a different car, the 2011 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

Air Conditioning Amplifier

Fig 1: Identifying Air Conditioning Amplifier Connector Terminal Identification

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Terminal No. (Symbol)	Wiring color	Terminal Description	Condition	Specification
D37-1 (B) - D37-20 (GND)	SB - B	Power source (Back-up)	Always	10 to 14 V
D37-2 (SHR) - D37-20 (GND)	Y - B	Seat heater operation signal (Passenger side)	Ignition switch on (IG). Seat heater switch: OFF	10 to 14 V
D37-2 (SHR) - D37-20 (GND)	Y -B	Seat heater operation signal (Passenger side)	Ignition switch on (IG). Seat heater switch: ON	Below 1 V
D37-3 (MGC) - Body ground	V - Body ground	Compressor operation signal	Ignition switch on (IG). Magnetic clutch: ON	Below 1 V
D37-3 (MGC) - Body ground	V - Body ground	Compressor operation signal	Ignition switch on (IG). Magnetic clutch: OFF	10 to 14 V
D37-4 (SCLI) - D37-20 (GND)	P - B	Illumination signal	Ignition switch on (IG). Seat heater switch: ON	Below 1 V
D37-4 (SCLI) - D37-20 (GND)	P - B	Illumination signal	Ignition switch on (IG). Seat heater switch: OFF	10 to 14 V
D37-5 (SOL+) - Body ground	L - Body ground	External variable control solenoid current value signal	Ignition switch on (IG). AUTO switch: ON	Pulse generation
D37-6 (SCRI) - D37-20 (GND)	B - B	Illumination signal	Ignition switch on (IG). Seat heater switch: ON	Below 1 V
D37-6 (SCRI) - D37-20 (GND)	B - B	Illumination signal	Ignition switch on (IG). Seat heater switch: OFF	10 to 14 V
D37-9 (LOCK) - D37-17 (SG-3)	BE - W	A/C lock sensor signal	Engine running. Magnetic clutch: ON Blower switch: ON	Pulse generation (See Fig 3waveform 2)
D37-11 (BLW) - D37-20 (GND)	R - B	Blower motor speed control signal	Ignition switch on (IG). Blower switch: ON	Pulse generation (See Fig 2waveform 1)
D37-13 (PRE) - D37-38 (SG-2)	G - R	A/C pressure sensor signal	Start engine Operate A/C system Refrigerant pressure: Abnormal pressure (More than 3,030 kPa (31.0 kgf/cm² , 440 psi))	4.7 V or higher
D37-13 (PRE) - D37-38 (SG-2)	G - R	A/C pressure sensor signal	Start engine Operate A/C system Refrigerant pressure: Abnormal pressure (Less than 180 kPa (1.9 kgf/cm² , 27 psi))	Below 0.7 V
D37-13 (PRE) - D37-38 (SG-2)	G - R	A/C pressure sensor signal	Start engine Operate A/C system Refrigerant pressure: Abnormal pressure (Less than 3,030 kPa (31.0 kgf/cm² , 440 psi) and more than 180 kPa (1.9 kgf/cm² , 27 psi))	0.7 to 4.7 V
D37-14 (TSP) - D37-20 (GND)	Y - B	Solar sensor signal (Passenger side)	Ignition switch on (IG). Solar sensor subjected to electric light.	0.8 to 4.3 V
D37-14 (TSP) - D37-20 (GND)	Y - B	Solar sensor signal (Passenger side)	Ignition switch on (IG). Solar sensor covered by cloth.	Below 0.8 V
D37-16 (TR) - D37-19 (SG-1)	BR - LG	Room temperature sensor signal	Ignition switch on (IG). Cabin temperature 25°C (77°F).	1.8 to 2.2 V
D37-16 (TR) - D37-19 (SG-1)	BR - LG	Room temperature sensor signal	Ignition switch on (IG). Cabin temperature 40°C (104°F).	1.2 to 1.6 V
D37-20 (GND) - Body ground	B - Body ground	Ground for main power supply	Always	Below 1 V
D37-21 (IG+) - D37-20 (GND)	G - B	Power source (IG)	Ignition switch on (IG).	10 to 14 V
D37-21 (IG+) - D37-20 (GND)	G - B	Power source (IG)	Ignition switch off.	Below 1 V
D37-22 (LIN1) - D37-20 (GND)	GR - B	LIN communication signal	Ignition switch on (IG).	Pulse generation
D37-24 (SHL) - D37-20 (GND)	W - B	Seat heater operation signal (Driver side)	Ignition switch on (IG). Seat heater switch: OFF	10 to 14 V
D37-24 (SHL) - D37-20 (GND)	W - B	Seat heater operation signal (Driver side)	Ignition switch on (IG). Seat heater switch: ON	Below 1 V
D37-26 (S5-2) - D37-38 (SG-2)	BR - R	Pressure sensor operation voltage	Ignition switch on (IG).	4.5 to 5.5 V
D37-28 (TACO) - D37-20 (GND)	V - B	Engine speed signal	Engine running. A/C switch: ON	Pulse generation (See Fig 4waveform 3)
D37-30 (MPX+) - D37-20 (GND)	(¹ ) LG - B, (² ) B - B	Multiplex communication system	Multiplex communication circuit	Pulse generation
D37-31 (MPX-) - D37-20 (GND)	L - B	Multiplex communication system	Multiplex communication circuit	Pulse generation
D37-35 (TSD) - D37-20 (GND)	BE - B	Solar sensor signal (Driver side)	Ignition switch on (IG). Solar sensor subjected to electric light.	0.8 to 4.3 V
D37-35 (TSD) - D37-20 (GND)	BE - B	Solar sensor signal (Driver side)	Ignition switch on (IG). Solar sensor covered by cloth.	Below 0.8 V
D38-2 (SW 5) - D38-10 (SG-4)	GR - SB	Seat heater control signal (Driver side)	Seat heater switch: COOL (HI)	0.17 V
D38-2 (SW 5) - D38-10 (SG-4)	GR - SB	Seat heater control signal (Driver side)	Seat heater switch: COOL (MID)	0.48 to 1.17 V
D38-2 (SW 5) - D38-10 (SG-4)	GR - SB	Seat heater control signal (Driver side)	Seat heater switch: COOL (LO)	1.31 to 2.01 V
D38-2 (SW 5) - D38-10 (SG-4)	GR - SB	Seat heater control signal (Driver side)	Seat heater switch: OFF	2.15 to 2.83 V
D38-2 (SW 5) - D38-10 (SG-4)	GR - SB	Seat heater control signal (Driver side)	Seat heater switch: HOT (LO)	2.97 to 3.67 V
D38-2 (SW 5) - D38-10 (SG-4)	GR - SB	Seat heater control signal (Driver side)	Seat heater switch: HOT (MID)	3.81 to 4.49 V
D38-2 (SW 5) - D38-10 (SG-4)	GR - SB	Seat heater control signal (Driver side)	Seat heater switch: HOT (HI)	4.8 V
D38-3 (SW 4) - D38-10 (SG-4)	BR - SB	Seat heater control signal (Passenger side)	Seat heater switch: COOL (HI)	0.17 V
D38-3 (SW 4) - D38-10 (SG-4)	BR - SB	Seat heater control signal (Passenger side)	Seat heater switch: COOL (MID)	0.48 to 1.17 V
D38-3 (SW 4) - D38-10 (SG-4)	BR - SB	Seat heater control signal (Passenger side)	Seat heater switch: COOL (LO)	1.13 to 2.01 V
D38-3 (SW 4) - D38-10 (SG-4)	BR - SB	Seat heater control signal (Passenger side)	Seat heater switch: OFF	2.15 to 2.83 V
D38-3 (SW 4) - D38-10 (SG-4)	BR - SB	Seat heater control signal (Passenger side)	Seat heater switch: HOT (LO)	2.97 to 3.67 V
D38-3 (SW 4) - D38-10 (SG-4)	BR - SB	Seat heater control signal (Passenger side)	Seat heater switch: HOT (MID)	3.81 to 4.49 V
D38-3 (SW 4) - D38-10 (SG-4)	BR - SB	Seat heater control signal (Passenger side)	Seat heater switch: HOT (HI)	4.8 V
D38-4 (TSHR) - D38-11 (SG7)	L - BE	Seat heater temperature sensor signal (Passenger side)	Ignition switch on (IG). Temperature of seat heater sensor: 30°C (86°F).	2.6 to 3.0 V
D38-4 (TSHR) - D38-11 (SG7)	L - BE	Seat heater temperature sensor signal (Passenger side)	Ignition switch on (IG). Temperature of seat heater sensor: 50°C (122°F).	1.8 to 2.2 V
D38-5 (TSHL) - D38-12 (SG8)	LG - R	Seat heater temperature sensor signal (Driver side)	Ignition switch on (IG). Temperature of seat heater sensor: 30°C (86°F).	2.6 to 3.0 V
D38-5 (TSHL) - D38-12 (SG8)	LG - R	Seat heater temperature sensor signal (Driver side)	Ignition switch on (IG). Temperature of seat heater sensor: 50°C (122°F).	1.8 to 2.2 V
D38-7 (S5-4) - D38-10 (SG-4)	V - SB	Seat heater switch position sensor signal	Ignition switch on (IG).	4.5 to 5.5 V
D38-8 (ROUT) - D37-20 (GND)	W - B	Seat climate blower control signal (Passenger side)	Ignition switch on (IG). Seat climate control blower dial (Passenger side): Minimum → Maximum	Pulse generation (See Fig 2waveform 1)
D38-11 (SG7) - D37-20 (GND)	BE - B	Ground for seat heater sensor (Passenger side)	Always	Below 1 V
D38-12 (SG8) - D37-20 (GND)	R - B	Ground for seat heater sensor (Driver side)	Always	Below 1 V
D38-16 (LOUT) - D37-20 (GND)	GR - B	Seat climate blower control signal (Driver side)	Ignition switch on (IG). Seat climate control blower dial (Driver side): Minimum → Maximum	Pulse generation (See Fig 2waveform 1)
T1-2 (BUS G) - Body ground	-	Ground for BUS IC	Always	Below 1 V
T1-3 (BUS) - T1-2 (BUS G)	-	BUS IC control signal	Ignition switch off → on (IG)	Pulse generation
T1-4 (B BUS) - T1-2 (BUS G)	-	Power supply for BUS IC	Ignition switch off.	Below 1 V
T1-4 (B BUS) - T1-2 (BUS G)	-	Power supply for BUS IC	Ignition switch on (IG).	10 to 14 V
T1-6 (TEA) - T1-5 (SGA)	-	Evaporator temperature sensor signal	Ignition switch on (IG). Evaporator temperature 0°C (32°F).	2.0 to 2.4 V
T1-6 (TEA) - T1-5 (SGA)	-	Evaporator temperature sensor signal	Ignition switch on (IG). Evaporator temperature 15°C (59°F).	1.4 to 1.8 V

(*¹ ): w/ Smart Key System

(*² ): w/o Smart Key System

waveform 1:

Fig 2: View Of Waveform Graph 1
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Measure the waveform between terminal D37-11 (BLW), D38-16 (LOUT), D38-8 (ROUT) and body ground or air conditioning amplifier.
  OK
  
  Waveform appears as shown in the illustration.
  
  HINT:
  
  As the air flow amount increases, the waveform gets narrow.
waveform 2:

Fig 3: View Of Waveform Graph 2
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Measure the waveform between terminal D37-9 (LOCK) and body ground of air conditioning amplifier
  OK
  
  Waveform appears as shown in the illustration.
waveform 3:

Fig 4: View Of Waveform Graph 3
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Measure the waveform between terminal D37-28 (TACO) and body ground of air conditioning amplifier
  OK
  
  Waveform appears as shown in the illustration.
  
  HINT:
  
  As the engine speed becomes faster, the waveform gets narrow.

A/C Control Assembly

Fig 5: Identifying A/C Control Assembly Connector Terminal Identification

Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
D59-1 (GND) - Body ground	B - Body ground	Ground	Always	Below 1 V
D59-3 (LIN1) - Body ground	GR - Body ground	LIN communication signal	Ignition switch on (IG)	Pulse generation
D59-7 (ILL+) - D59-12 (ILL-)	W - V	Illumination signal	Ignition switch on (IG), light control switch: TAIL or HEAD	10 to 14 V
D59-9 (SG) - Body ground	R - Body ground	Ground for steering pad switch assembly	Always	Below 1 V
D59-16 (IG+) - Body ground	LG - Body ground	Power source (IG)	Ignition switch off.	Below 1 V
D59-16 (IG+) - Body ground	LG - Body ground	Power source (IG)	Ignition switch on (IG)	11 to 14 V