DYNAMIC RADAR CRUISE CONTROL SYSTEM > ECU Power Source Circuit

for Preparation Click here


DESCRIPTION

  1. The driving support ECU assembly controls the cruise control system based on information sent from switches, sensors and ECUs.
  2. The power management control ECU sends current to the IG1 No. 1 relay. This closes the contact points in the relay so that power is supplied to the driving support ECU assembly +B terminal.

WIRING DIAGRAM


E224022E01


INSPECTION PROCEDURE

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

1.CHECK DRIVING SUPPORT ECU ASSEMBLY (+B VOLTAGE)


    E178930E57

  1. Disconnect the driving support ECU assembly connector.

  1. Turn the power switch on (IG).

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    H5-30 (B) - Body ground
    		Power switch on (IG)
    		11 to 14 V

    Text in Illustration 
    *a
    		Front view of wire harness connector
    (to Driving Support ECU assembly)

  1. Reconnect the driving support ECU assembly connector.



NG
Go to step 3
OK


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


    E178930E58

  1. Disconnect the driving support ECU assembly connector.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    H5-25 (GND) - Body ground
    		Always
    		Below 1 Ω

    Text in Illustration 
    *a
    		Front view of wire harness connector
    (to Driving Support ECU assembly)

  1. Reconnect the driving support ECU assembly connector.



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

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

3.INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


  1. Remove the instrument panel junction block assembly.


    A217170E01

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

    Standard Resistance (for LHD):
    Tester Connection
    		Condition
    		Specified Condition
    2E-1 - 2B-2
    		Always
    		10 kΩ or higher
    2E-1 - 2B-2
    		Battery voltage applied between terminals 2B-25 and 2B-6
    		Below 1 Ω

    Standard Resistance (for RHD):
    Tester Connection
    		Condition
    		Specified Condition
    2F-1 - 2B-2
    		Always
    		10 kΩ or higher
    2F-1 - 2B-2
    		Battery voltage applied between terminals 2B-25 and 2B-6
    		Below 1 Ω


    Text in Illustration 
    *1
    		Instrument Panel Junction Block Assembly
    		-
    		-

  1. Reinstall the instrument panel junction block assembly.



NG
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
OK


4.CHECK HARNESS AND CONNECTOR (DRIVING SUPPORT ECU - INSTRUMENT PANEL JUNCTION BLOCK)

  1. Disconnect the driving support ECU assembly connector.

  1. Disconnect the instrument panel junction block assembly connector.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    H5-30 (B) - 2B-2
    		Always
    		Below 1 Ω

  1. Reconnect the instrument panel junction block assembly connector.

  1. Reconnect the driving support ECU assembly connector.



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


5.CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK POWER SOURCE CIRCUIT)


  1. Disconnect the instrument panel junction block assembly connector.


    A217171E01

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

    Standard Voltage (for LHD):
    Tester Connection
    		Switch Condition
    		Specified Condition
    2E-1 - Body ground
    		Always
    		11 to 14 V

    Standard Voltage (for RHD):
    Tester Connection
    		Switch Condition
    		Specified Condition
    2F-1 - Body ground
    		Always
    		11 to 14 V


    Text in Illustration 
    *1
    		Instrument Panel Junction Block Assembly
    		-
    		-

  1. Reconnect the instrument panel junction block assembly connector.



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


6.CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BODY GROUND)


    E189244E03

  1. Disconnect the instrument panel junction block assembly connector.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    2B-6 - Body ground
    		Always
    		Below 1 Ω

    Text in Illustration 
    *1
    		Instrument Panel Junction Block Assembly

  1. Reconnect the instrument panel junction block assembly connector.



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


7.CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - INSTRUMENT PANEL J/B ASSEMBLY)

  1. Disconnect the power management control ECU connector.

  1. Disconnect the instrument panel junction block assembly connector.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    2B-25 - H4-2 (IG1D)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    2B-25 or H4-2 (IG1D) - Body ground
    		Always
    		10 kΩ or higher

  1. Reconnect the power management control ECU connector.

  1. 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

GO TO ENTRY AND START SYSTEM (Click here)