Millimeter Wave Radar Sensor Power Source Circuit: Procedure

CHECK DISTANCE CONTROL ECU (IGB VOLTAGE)

Fig 1: Identifying A31 Connector Terminals

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Measure the voltage according to the value(s) in the table below.

Standard voltage

Tester Connection	Condition	Specified Condition
A31-5 (IGB) - Body ground	Engine switch on (IG)	10 to 14 V

NG → See step 3

OK: Go to next step

CHECK WIRE HARNESS (MILLIMETER WAVE RADAR SENSOR - ECM AND BODY GROUND)

Disconnect the A31 sensor connector.

Fig 2: Identifying A31 And A10 Connectors Terminals
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Disconnect the A10 ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard resistance

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK → PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

CHECK WIRE HARNESS (MILLIMETER WAVE RADAR SENSOR - DISTANCE CONTROL ECU)

Disconnect the A31 sensor connector.

Fig 3: Identifying A31 And A8 Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Disconnect the A8 ECU connector.

Measure the resistance according to the value(s) in the table below

Standard resistance

Tester Connection	Condition	Specified Condition
A31-5 (IGB) - A8-13 (IGB)	Always	Below 1 Ω
A8-13 (IGB) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK → See step 4