Terminals Of Ecu

Fig 1: Identifying D4 Relay Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the D4 relay connector.
2. Measure the voltage and resistance of each terminal of the wire harness side connector.

   Standard: 

   D4 RELAY CONNECTOR (DISCONNECTED) SPECIFICATIONS
   
   

   Symbols (Terminal No.)	Wiring Color	Terminal Description	Condition	Specified Condition
   B (D4-1) - Body ground	L-W - Body ground	+B (B) power supply	Always	10 to 14 V
   E (D4-12) - Body ground	W-B - Body ground	Ground	Always	Below 1 Ω
   IG (D4-26) - Body ground	R-B - Body ground	Ignition power supply	Ignition switch ON	10 to 14 V
   KSW (D4-8) - Body ground	Y - Body ground	Key unlock warning switch input	No key in ignition key cylinder --> Key inserted	10 kΩ or higher --> Below 1 Ω
   DCTY (D4-5) - Body ground	R - Body ground	Driver side courtesy switch input	Driver side door Closed --> Open	10 kΩ or higher --> Below 1 Ω
   PCTY (D4-7) - Body ground	R-W - Body ground	Courtesy switch input other than driver side door	Passenger side door, rear door (LH, RH) or back door Closed --> Open	10 kΩ or higher --> Below 1 Ω
   L1 (D4-18) - Body ground	BR-Y - Body ground	Door control switch (master switch and passenger side switch) lock input	Door control switch (master switch or passenger side switch) OFF --> LOCK	10 kΩ or higher --> Below 1 Ω
   UL1 (D4-19) - Body ground	G-B - Body ground	Door control switch (master switch and passenger side switch) unlock input	Door control switch (master switch or passenger side switch) OFF --> UNLOCK	10 kΩ or higher --> Below 1 Ω
   LSWD (D4-6) - Body ground	L-R - Body ground	Driver side door lock position switch input	Driver side door UNLOCK --> LOCK	10 kΩ or higher --> Below 1 Ω
   L2 (D4-20) - Body ground	L-W - Body ground	Driver and passenger side door key-linked door lock input	Driver side or passenger side door key cylinder OFF --> LOCK	10 kΩ or higher --> Below 1 Ω
   UL3 (D4-21) - Body ground	Y-B - Body ground	Driver side door key-linked door unlock input	Driver side door key cylinder OFF --> UNLOCK	10 kΩ or higher --> Below 1 Ω
   UL2 (D4-22) - Body ground	L-R - Body ground	Passenger side door key-linked door unlock input	Passenger side door key cylinder OFF --> UNLOCK	10 kΩ or higher --> Below 1 Ω
   BDSU (D4-17) - Body ground	BR-Y - Body ground	Back door opener switch input	Back door opener switch (outside handle switch) OFF --> ON	10 kΩ or higher --> Below 1 Ω

   If the result is not as specified, there may be a malfunction on the wire harness side.

3. Reconnect the D4 relay connector.
4. Measure the voltage of each terminal of the connector.

Standard: 

Fig 2: D4 Relay Connector (Connected) Specifications

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If the result is not as specified, the relay may have a malfunction.