TIRE PRESSURE WARNING SYSTEM TERMINALS OF ECU

CHECK TIRE PRESSURE WARNING ECU AND RECEIVER

1. 

   *A	w/ Smart Entry and Start System
   *B	w/o Smart Entry and Start System
   *a	Front view of wire harness connector (to Tire Pressure Warning ECU and Receiver)

   Disconnect the R9 or R120 tire pressure warning ECU and receiver connector and measure the voltage or resistance on the wire harness side.

   Table 1. w/ Smart Entry and Start System

   Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
   R9-1 (IG) - R9-12 (GND)	LA-B - BR	IG power source	Ignition switch ON	10 to 16 V
   R9-7 (+B) - R9-12 (GND)	LA-R - BR	Power supply (from battery)	Always	10 to 16 V
   R9-9 (CANH) - R9-10 (CANL)*	L - W	CAN communication line	Ignition switch off	54 to 69 Ω
   R9-12 (GND) - Body ground	BR - Body ground	Ground	Always	Below 1 Ω

   
   

   • *: w/ Tire Inflation Pressure Display Function

   Table 2. w/o Smart Entry and Start System

   Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
   R120-1 (IG) - R120-12 (GND)	LA-B - BR	IG power source	Ignition switch ON	10 to 16 V
   R120-7 (+B) - R120-12 (GND)	LA-R - BR	Power supply (from battery)	Always	10 to 16 V
   R120-12 (GND) - Body ground	BR - Body ground	Ground	Always	Below 1 Ω

2. Connect the R9 or R120 tire pressure warning ECU and receiver connector.

3. 

   *A	w/ Smart Entry and Start System	*B	w/o Smart Entry and Start System
   *a	Component with harness connected (Tire Pressure Warning ECU and Receiver)	-	-

   Measure the voltage according to the value(s) in the table below. If the result is not as specified, the ECU may be malfunctioning.

   Tip:

   Measure the values on the wire harness side while the connector is connected.

   Table 3. w/ Smart Entry and Start System

   Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
   R9-3 (CLSW) - R9-12 (GND)	SB - BR	Tire pressure warning reset switch	Ignition switch ON Steering pad switch assembly operated, "Set Pressure" selected on the multi-information display and "OK" switch (steering pad switch assembly) pressed and held	Below 1.5 V
   			Ignition switch ON "OK" switch (steering pad switch assembly) off	8 to 15 V
   R9-4 (RDA) - R9-12 (GND)	GR - BR	Output signals	Ignition switch ON	Pulse generation (see waveform 1)
   R9-5 (PRG) - R9-12 (GND)	R - BR	Input signals	Ignition switch ON	Pulse generation (see waveform 1)

   Table 4. w/o Smart Entry and Start System

   Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
   R120-3 (CLSW) - R120-12 (GND)	SB - BR	Tire pressure warning reset switch	Ignition switch ON Steering pad switch assembly operated, "Set Pressure" selected on the multi-information display and "OK" switch (steering pad switch assembly) pressed and held	Below 1.5 V
   			Ignition switch ON "OK" switch (steering pad switch assembly) off	8 to 15 V
   R120-4 (RDA) - R120-12 (GND)	GR - BR	Output signals	Ignition switch ON	Pulse generation (see waveform 1)
   R120-5 (PRG) - R120-12 (GND)	R - BR	Input signals	Ignition switch ON	Pulse generation (see waveform 1)

4. 

   *a	Example
   *b	GND

   Using an oscilloscope, check waveform 1.

   Table 5. Waveform 1:

   Item	Contents
   Terminal	R9-4 (RDA) - R9-12 (GND)*1 R120-4 (RDA) - R120-12 (GND)*2 R9-5 (PRG) - R9-12 (GND)*1 R120-5 (PRG) - R120-12 (GND)*2
   Tool setting	5 V/DIV, 5 ms./DIV.
   Vehicle condition	Ignition switch ON

   
   

   • *1: w/ Smart Entry and Start System

   • *2: w/o Smart Entry and Start System

   Tip:

   The waveform shown in the illustration is an example. If the tester displays a waveform that alternates between high and low, where high is a voltage that is between the IG power source voltage and a voltage 2.2 V lower than the IG power source voltage, and where low is a voltage of between 0 and 1.2 V, the ECU can be judged normal.