DYNAMIC RADAR CRUISE CONTROL SYSTEM ECU Power Source Circuit

DESCRIPTION

• The driving support ECU assembly controls the cruise control system based on information sent from switches, sensors and ECUs.

• 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

INSPECTION PROCEDURE

PROCEDURE

1. CHECK DRIVING SUPPORT ECU ASSEMBLY (B VOLTAGE)

   
   
   1. 

      Text in Illustration

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

      Disconnect the driving support ECU assembly 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 Condition Specified Condition L54-30 (B) - Body ground Power switch on (IG) 11 to 14 V

   
   

   NG

   INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

   OK

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

   
   
   1. 

      Text in Illustration

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

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition L54-25 (GND) - Body ground Always Below 1 Ω

   
   

   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.

      

   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 Auxiliary battery voltage applied between terminals 2B-25 and 2B-6 Below 1 Ω

      Text in Illustration

      *a

      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 instrument panel junction block assembly connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition L54-30 (B) - 2B-16 Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition L54-30 (B) or 2B-16 - Body ground Always 10 kΩ or higher

   
   

   NG

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

   OK

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

   
   
   1. 

      Text in Illustration

      *a	Instrument Panel Junction Block Assembly

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition 2B-4 - Body ground Always Below 1 Ω

   
   

   NG

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

   OK

6. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

   
   

   1. Disconnect the power management control 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 L6-2 (IG1D) - 2B-25 Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition L6-2 (IG1D) or 2B-25 - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

   OK

   REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - AUXILIARY BATTERY)