Lexus IS250 · Service Manual RESTRAINTS

SRS Warning Light does not Come ON

Circuit diagnosis

DESCRIPTION

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WIRING DIAGRAM

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INSPECTION PROCEDURE


1. CHECK BATTERY
  1. Measure the voltage of the battery.

    Standard voltage:
    11 to 14 V



NG
CHECK AND REPLACE BATTERY OR CHARGING SYSTEM
OK


2. CHECK CONNECTORS
  1. Turn the engine switch off.

  1. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

  1. Check that the connectors are properly connected to the center airbag sensor assembly and the combination meter assembly.

    OK:
    The connectors are properly connected.



NG
CONNECT CONNECTORS, THEN GO TO STEP 1
OK


3. CHECK WIRE HARNESS (SOURCE VOLTAGE OF COMBINATION METER)

  1. E113277E02
    Turn the engine switch off.

  1. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

  1. Disconnect the J34 connector from the combination meter assembly.

  1. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

  1. Turn the engine switch on (IG).

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

    Standard voltage:
    Tester connection
    Condition
    Specified condition
    J34-12 (IG+) - Body ground
    Engine switch on (IG)
    10 to 16 V
    J34-23 (B) - Body ground
    Always
    10 to 16 V
    J34-24 (B) - Body ground
    Always
    10 to 16 V

  1. Turn the engine switch off.

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

    Standard resistance:
    Tester connection
    Condition
    Specified condition
    J34-1 (E2) - Body ground
    Always
    Below 1 Ω
    J34-13 (ES) - Body ground
    Always
    Below 1 Ω



NG
REPAIR OR REPLACE WIRE HARNESS
OK


4. CHECK SRS WARNING LIGHT
  1. Turn the engine switch off.

  1. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.

  1. Disconnect the connectors from the center airbag sensor assembly.

  1. Connect the J34 connector to the combination meter assembly.

  1. Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

  1. Turn the engine switch on (IG).

  1. Check the SRS warning light condition.

    OK:
    The SRS warning light turns on approximately 10 seconds after turning the engine switch on (IG).

    HINT:
    The primary check period is approximately 6 seconds after the ignition switch is turned on (IG).



NG
GO TO COMBINATION METER SYSTEM
OK

REPLACE CENTER AIRBAG SENSOR ASSEMBLY


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