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

   Below 1 Ω

NG → REPLACE FUSE 

OK: Go to next step 

Fig 1: Inspecting IG1 Relay

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the IG1 relay from the driver side junction block.
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 IG1 RELAY 

OK: Go to next step 

Fig 2: Identifying D19 ECU

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the D19 ECU connector.
2. Measure the voltage and resistance of the wire harness side connector.

   Standard voltage

   Standard resistance 

   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

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

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE MULTIPLEX NETWORK FRONT DOOR ECU LH