Terminals Of Ecu

Fig 1: Identifying Air Conditioning Amplifier Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Measure the voltage of the connectors.

   HINT:

   Check from the rear of the connector while it is connected to the air conditioning amplifier.

   AIR CONDITIONING AMPLIFIER CONNECTOR TERMINALS REFERENCE CHART
   
   

   Tester Connection	Wiring Color	Terminal Description	Condition	Specified Condition
   D37-1 (IG+) - D37-14 (GND)	GR - W-B	Power source (IG)	Ignition switch on (IG)	11 to 14 V
   D37-2 (SOL+) - D37-14 (GND)	L-W-B	A/C compressor operation signal	Engine idling	Pulse generation (see waveform 1  b)
   			Blower switch LO
   			A/C switch ON
   D37-3 (PTC1) - Body ground (*1)	P - Body ground	PTC NO. 1 heater relay operation signal	Engine idling	Below 1 V→11 to 14 V
   			Set temperature: MAX HOT
   			Engine coolant temperature: Below 65°C (149°F)
   			Ambient temperature: Below 10°C(50°F)
   			Blower switch OFF → LO
   D37-4 (PTC3) - Body ground (*1)	W - Body ground	PTC NO. 3 heater relay operation signal	Engine idling	Below 1 V→11 to 14 V
   			Set temperature: MAX HOT
   			Engine coolant temperature: Below 65°C (149-F)
   			Ambient temperature: Below 10°C(50°F)
   			Blower switch OFF → LO
   D37-5 (TAM) - D37-14 (GND)	B-W-B	Ambient temperature sensor signal	Ignition switch on (IG)	1.8 to 2.2 V
   			Ambient temperature: 25°C (77°F)
   D37-8 (LOCK) - D37-14 (GND)	V-W-B	Air compressor lock sensor signal	Engine idling	Pulse generation (see waveform 5  f)
   			A/C switch ON
   			Blower switch LO
   D37-9 (PRE) - D37-13 (SG-2)	R-SB	Air conditioning pressure sensor signal	Refrigerant pressure: Normal	0.76 to 4.74 V
   D37-9 (PRE) - D37-13 (SG-2)	R-SB	Air conditioning pressure sensor signal	Refrigerant pressure: Abnormal (less than 0.196 MPa [2.0 kgf/cm2 , 28 psi])	0.5 to 4.83 V
   D37-9 (PRE) - D37-13 (SG-2)	R-SB	Air conditioning pressure sensor signal	Refrigerant pressure: Abnormal (more than 3.14 MPa [32 kgf/cm2 , 455 psi])	4.74 V or higher
   D37-10 (S5-3) - D37-14 (GND)	O-W-B	Power supply for pressure sensor	Ignition switch on (IG)	4.5 to 5.5 V
   D37-11 (CANH) - D37-14 (GND)	LG - W-B	Hi-level CAN bus line	Ignition switch on (IG)	Pulse generation (see waveform 3  d)
   D37-12 (CANL) - D37-14 (GND)	W-W-B	Lo-level CAN bus line	Ignition switch on (IG)	Pulse generation (see waveform 4  e)
   D37-13 (SG-2) - Body ground	SB - Body ground	Ground for pressure sensor	Always	Below 1 V
   D37-14 (GND) - Body ground	W-B - Body ground	Ground for main power supply	Always	Below 1 V
   D37-20 (MGC) - D37-14 (GND)	V-W-B	A/C compressor magnetic clutch operation signal	Engine idling	Below 1 V
   			Blower switch LO
   			A/C switch ON
   D37-21 (B) - D37-14 (GND)	LG - W-B	Power source (Back-up)	Always	11 to 14 V
   D37-22 (PTC2) - Body ground (*1)	G - Body ground	PTC NO. 2 heater relay operation signal	Engine idling	Below 1V→ 11 to 14 V
   			Set temperature: MAX HOT
   			Engine coolant temperature: Below 65°C (149°F)
   			Ambient temperature: Below 10°C (50°F)
   			Blower switch OFF → LO
   D37-23 (BLW) - D37-14 (GND)	R-W-B	Blower motor control signal	Ignition switch on (IG)	Pulse generation (see waveform 2  c)
   			Blower switch LO
   D37-25 (ALT) - Body ground (*1)	SB - Body ground	Generator signal	Engine idling	Pulse generation
   D37-37 (LIN1) - D37-14 (GND)	R-W-B	LIN communication signal	Ignition switch on (IG)	Pulse generation
   D37-38 (RDEF) - D37-14 (GND)	W-W-B	Rear defogger switch signal	Ignition switch on (IG) Rear defogger switch OFF	11 to 14 V
   D37-38 (RDEF) - D37-14 (GND)	W-W-B	Rear defogger switch signal	Ignition switch on (IG) Rear defogger switch ON	Below 1 V
   Z17-2 (BUS G) - Body ground	-	Ground for BUS IC	Always	Below 1 V
   z17-3 (BUS) - z17-2 (BUS G)	-	BUS IC control signal	Ignition switch on (IG)	Pulse generation
   z17-4 (BBUS) - z17-2 (BUS G)	-	Power supply for BUS IC	Ignition switch on (IG)	11 to 14 V
   z17-5 (SGA) - Body ground	-	Ground for evaporator temperature sensor	Always	Below 1 V
   z17-6 (TEA) - z17-5 (SGA)	-	Evaporator temperature sensor signal	Ignition switch on (IG)	1.4 to 1.8 V
   			Evaporator temperature: 15°C(59°F)

2. Using an oscilloscope, check waveform 1.

   Compressor and pulley operation signal 

   WAVEFORM REFERENCE CHART
   
   

   Item	Content
   Tester Connection	D37-2 (SOL+) - D37-14 (GND)
   Tool Setting	5 V/DIV., 500 μsec/DIV.
   Condition	Engine idling, Blower switch LO, A/C switch ON

   Fig 2: Waveform 1 Graph

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Using an oscilloscope, check waveform 2.

   Blower motor control signal 

   WAVEFORM REFERENCE CHART
   
   

   Item	Content
   Tester Connection	D37-23 (BLW) - D37-14 (GND)
   Tool Setting	1 V/DIV., 500 μsec./DIV.
   Condition	Ignition switch on (IG), Blower switch LO

   HINT:

   When the blower level is increased, the duty ratio changes accordingly.

   Fig 3: Waveform 2 Graph

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Using an oscilloscope, check waveform 3.

   CAN communication signal 

   WAVEFORM REFERENCE CHART
   
   

   Item	Content
   Tester Connection	D37-11 (CANH) - D37-14 (GND)
   Tool Setting	1 V/DIV, 10 μsec./DIV.
   Condition	Ignition switch on (IG)

   HINT:

   The waveform varies depending on the CAN communication signal.

   Fig 4: Waveform 3 Graph

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. Using an oscilloscope, check waveform 4.

   CAN communication signal 

   WAVEFORM REFERENCE CHART
   
   

   Item	Content
   Tester Connection	D37-12 (CANL) - D37-14 (GND)
   Tool Setting	1 V/DIV., 10 μsec./DIV.
   Condition	Ignition switch on (IG)

   HINT:

   The waveform varies depending on the CAN communication signal.

   Fig 5: Waveform 4 Graph

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. Using an oscilloscope, check waveform 5.

A/C compressor lock sensor signal 

HINT:

The waveform varies depending on the CAN communication signal.

*1: w/ PTC Heater

Fig 6: Waveform 5 Graph

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 7: Identifying Front Air Conditioning Control Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Measure the voltage of the connectors.