Driver Side Door ECU Power Source Circuit: Procedure

1. Remove the MPX-IG and AM1 fuses from the driver side junction block.
2. Remove the MPX-B1 fuse from the passenger side junction block.
3. Remove the D-DOOR and D/C CUT fuses from the engine room No. 1 relay block.
4. Measure the resistance of the fuses.

   Standard resistance

   Below 1 Ω

NG → REPLACE FUSE 

OK: Go to next step 

1. Remove the IG1 relay from the driver side junction block.
   Fig 1: Identifying IG1 Relay Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance of the relay.

   Standard resistance

   Tester Connection	Specified Condition
   3 - 5	10 kΩ or higher
   3 - 5	Below 1 Ω (when battery voltage is applied to terminals 1 and 2)

NG → REPLACE RELAY 

OK: Go to next step 

1. Disconnect the D19 ECU connector.
   Fig 2: Identifying D19 ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance and voltage of the wire harness side connector.

   Standard resistance

   Standard voltage 

   Tester Connection	Condition	Specified Condition
   D19-1 (GND) - Body ground	Always	Below 1 Ω

   Tester Connection	Condition	Specified Condition
   D19-4 (CPUB) - Body ground	Always	10 to 14 V
   D19-6 (BDR) - Body ground	Always	10 to 14 V
   D19-5 (SIG) - Body ground	Ignition switch ON	10 to 14 V

NG → REPAIR OR REPLACE HARNESS AND CONNECTOR 

OK → REPLACE MULTIPLEX NETWORK DOOR ECU FRONT LH