ECU Power Source Circuit: Procedure

1. Disconnect the driving support ECU connector.
   Fig 1: Checking Driving Support ECU (B Voltage)

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2. Turn the power switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   F102-30 (B) - Body ground	Power switch on (IG)	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Driving Support ECU)

4. Reconnect the driving support ECU connector.

NG → See step   3 

OK: Go to next step 

1. Disconnect the driving support ECU connector.
   Fig 2: Check Harness And Connector (Driving Support ECU - Body Ground)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   F102-25 (GND) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Driving Support ECU)

3. Reconnect the driving support ECU connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVING SUPPORT ECU - BODY GROUND) 

OK → See step   8 

1. Remove the instrument panel junction block assembly.
   Fig 3: Inspecting Instrument Panel Junction Block Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   2E-1 - 2B-16	Always	10 kΩ or higher
   2E-1 - 2B-16	Battery voltage applied between terminals 2B-25 and 2B-6	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	Instrument Panel Junction Block Assembly

3. Reinstall the instrument panel junction block assembly.

NG → REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

OK: Go to next step 

1. Disconnect the driving support ECU connector.
2. Disconnect the instrument panel junction block assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   F102-30 (B) - 2B-16	Always	Below 1 Ω

   Standard Resistance (Check for Shortn)

   Tester Connection	Condition	Specified Condition
   F102-30 (B) or 2B-16 - Body ground	Always	10 kΩ or higher

4. Reconnect the instrument panel junction block assembly connector.
5. Reconnect the driving support ECU connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVING SUPPORT ECU - INSTRUMENT PANEL JUNCTION BLOCK) 

OK: Go to next step 

1. Disconnect the instrument panel junction block assembly connector.
   Fig 4: Checking Harness & Connector (Instrument Panel Junction Block Power Source Circuit)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   2E-1 - Body ground	Always	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *1	Instrument Panel Junction Block Assembly

3. Reconnect the instrument panel junction block assembly connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BATTERY) 

OK: Go to next step 

1. Disconnect the instrument panel junction block assembly connector.
   Fig 5: Identifying Instrument Panel Junction Block Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   2B-6 - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	Instrument Panel Junction Block Assembly

3. Reconnect the instrument panel junction block assembly connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BODY GROUND) 

OK: Go to next step 

1. Disconnect the power management control ECU connector.
2. Disconnect the instrument panel junction block assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   2B-25 - F52-20 (IG1D)	Always	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   2B-25 or F52-20 (IG1D) - Body ground	Always	10 kΩ or higher

4. Reconnect the power management control ECU connector.
5. Reconnect the instrument panel junction block assembly connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - INSTRUMENT PANEL J/B ASSEMBLY) 

OK → See step   9