Lexus IS250 · Service Manual SECURITIES

Engine Hood Courtesy Switch Circuit

Circuit diagnosis

DESCRIPTION

The engine hood courtesy switch is installed together with the hood lock. This switch turns on when the engine hood is opened and turns off when the engine hood is closed.

WIRING DIAGRAM

B125107E02

INSPECTION PROCEDURE


1. INSPECT DTC

HINT:
Front controller sends engine hood open/close signal to main body ECU RH through the multiplex communication.

  1. Delete DTC (Click here).

  1. Check the DTC B1214.

    OK:
    No DTC is output.



 NG
GO TO MULTIPLEX COMMUNICATION SYSTEM
OK


2. READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG).

  1. Turn the intelligent tester main switch on.

  1. Select the item below in the Data list and read the display on the tester.

    Body No. 5 (Front controller): 
    Item
    		 Test Details
    		 Diagnostic Note
    Hood Courtesy Switch
    		 Engine hood courtesy switch signal ON/OFF
    		 -

    OK:
    The indicator on the tester switches between ON and OFF in accordance with the engine hood courtesy switch status.



 NG
Go to step 3
OK

REPLACE ENGINE ROOM NO. 2 RELAY BLOCK AND JUNCTION BLOCK (FRONT CONTROLLER)

3. INSPECT ENGINE HOOD COURTESY SWITCH

  1. B108809E06
    Remove the courtesy switch from the hood lock.

  1. Disconnect the 2G R/B connector.

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

Standard resistance:
Tester Connection
 Switch Position
 Specified Condition
1 - 2
 Free (OFF)
 10 kΩ or higher
Pushed (ON)
 Below 1 Ω



NG
REPLACE HOOD LOCK ASSEMBLY
OK


4. CHECK HARNESS AND CONNECTOR (ENGINE ROOM R/B NO. 2 - ENGINE HOOD COURTESY SWITCH)

  1. B125078E01
    Disconnect the 2G R/B connector and B8 switch connector.

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

Standard resistance:
Tester Connection
 Specified Condition
2G-3 - B8-2
 Below 1 Ω
2G-3 or B8-2 - Body ground
 10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5. CHECK HARNESS AND CONNECTOR (ENGINE HOOD COURTESY SWITCH - BODY GROUND)

  1. B110524E03
    Measure the resistance according to the value(s) in the table below.

Standard resistance:
Tester Connection
 Specified Condition
B8-1 - Body ground
 Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE


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