April 5, 2026: LEMON Manuals is launched! Read the announcement.

Inspection Procedure

INSPECT FUSE (MPX-B1, AM1, MPX-IG, D-DOOR, D/C CUT)
1. Remove the MPX-IG and AM1 fuses from the driver side J/B.
2. Remove the MPX-B1 fuse from the passenger side J/B.
3. Remove the D-DOOR and D/C CUT fuses from the engine room No. 1 R/B.
4. Measure the resistance of the fuses.
  Standard: Below 1 ohms
1. NG: REPLACE FUSE
2. OK: Go to next step.

INSPECT RELAY (Marking: IG1)

Remove the IG1 relay from the driver side J/B.

Measure the resistance of the relay.

Standard:

RELAY (MARKING: IG1)

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

Fig 1: Inspecting Relay (IG1)

G02956652

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE RELAY
OK: Go to next step.

CHECK WIRE HARNESS (MULTIPLEX NETWORK DOOR ECU FRONT LH - BATTERY AND BODY GROUND

Disconnect the D19 ECU connector.

Measure the voltage and resistance of the wire harness side connector.

Standard:

MULTIPLEX NETWORK DOOR ECU FRONT LH - BATTERY AND BODY GROUND

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
D19-1 (GND) - Body ground	Always	Below 1 ohms

Fig 2: Checking Wire Harness (Multiplex Network Door ECU Front LH - Battery & Body Ground

G02956653

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS AND CONNECTOR
OK: REPLACE MULTIPLEX NETWORK DOOR ECU FRONT LH