DYNAMIC RADAR CRUISE CONTROL SYSTEM ECU Power Source Circuit

DESCRIPTION

This circuit provides power to operate the driving support ECU. The driving support ECU determines information about the vehicle in front based on data from the radar sensor, and then decides how much acceleration and/or deceleration is needed to maintain the set distance. The driving support ECU also requests the skid control ECU to apply braking and to sound the buzzer.

WIRING DIAGRAM

A01NHSHE01

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. CHECK DRIVING SUPPORT ECU (B VOLTAGE)


    1. A01NCOKE31
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Driving Support ECU)

      Disconnect the driving support ECU connector.

    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
      C1-30 (B) - Body ground Power switch on (IG) 11 to 14 V

    4. Reconnect the driving support ECU connector.


    NG

    INSPECT IG1 RELAY Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU - BODY GROUND)


    1. A01NCOKE09
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Driving Support ECU)

      Disconnect the driving support ECU connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      C1-25 (GND) - Body ground Always Below 1 Ω

    3. Reconnect the driving support ECU connector.


    NG

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

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

  3. INSPECT IG1 RELAY


    1. A01ND26E46

      Remove the IG1 relay from the engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 No battery voltage applied between terminals 1 and 2 10 kΩ or higher
      3 - 5 Battery voltage applied between terminals 1 and 2 Below 1 Ω

    3. Reinstall the IG1 relay.


    NG

    REPLACE IG1 RELAY

    OK

  4. CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU - IG1 RELAY)


    1. A01NDG2E05
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Driving Support ECU)
      *2 Engine Room Relay Block

      Disconnect the driving support ECU connector.

    2. Remove the IG1 relay from the engine room relay block.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      C1-30 (B) - IG1 relay side connector terminal 3 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      C1-30 (B) or IG1 relay side connector terminal 3 - Body ground Always 10 kΩ or higher

    4. Install the IG1 relay.

    5. Reconnect the driving support ECU connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVING SUPPORT ECU - IG1 RELAY)

    OK

  5. CHECK HARNESS AND CONNECTOR (IG1 RELAY POWER SOURCE CIRCUIT)


    1. A01NHH4E01
      Text in Illustration
      *1 Engine Room Relay Block

      Disconnect the IG1 relay from the engine room relay block.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      IG1 relay side connector terminal 5 - Body ground Always 11 to 14 V

    3. Reconnect the IG1 relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 RELAY - BATTERY)

    OK

  6. CHECK HARNESS AND CONNECTOR (IG1 RELAY - BODY GROUND)


    1. A01NHH4E01
      Text in Illustration
      *1 Engine Room Relay Block

      Disconnect the IG1 relay from the engine room relay block.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      IG1 relay side connector terminal 2 - Body ground Always Below 1 Ω

    3. Reconnect the IG1 relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 RELAY - BODY GROUND)

    OK

  7. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - IG1 RELAY)


    1. Disconnect the power management control ECU connector.

      A01NDBXE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Power Management Control ECU)

      		 *2 Engine Room Relay Block

    2. Remove the IG1 relay from the engine room relay block.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      1 (IG1 relay) - F98-2 (IG1D) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      1 (IG1 relay) or F98-2 (IG1D) - Body ground Always 10 kΩ or higher

    4. Reconnect the power management control ECU connector.

    5. Reinstall the IG1 relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - IG1 RELAY)

    OK

    GO TO ENTRY AND START SYSTEM Click here