Pre-Crash Safety System - Power Source Circuit

Lexus IS250 IS220d GSE20 ALE20 - PRE-CRASH SAFETY

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

CHECK HARNESS AND CONNECTOR (GROUND CIRCUIT)

PRE-CRASH SAFETY SYSTEM - Power Source Circuit

DESCRIPTION

This circuit supplies power to the seat belt control ECU.


WIRING DIAGRAM

Pre-Crash Safety System - Power Source Circuit. PRE-CRASH SAFETY. Lexus IS250 IS220d GSE20 ALE20

INSPECTION PROCEDURE

  • NOTICE:
  • When the seat belt control ECU is replaced with a new one, INITIALIZATION must be performed .
1.CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)
Pre-Crash Safety System - Power Source Circuit. PRE-CRASH SAFETY. Lexus IS250 IS220d GSE20 ALE20

Disconnect the negative (-) terminal cable from the battery.

Disconnect the O38 seat belt control ECU connector.

Connect the negative (-) terminal cable to the battery.

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

  • Standard voltage:
  • Tester ConnectionConditionSpecified Condition
    O38-3 (IG1) - Body groundEngine switch offBelow 1 V
    Engine switch on (IG)10 to 14 V
    O38-9 (+B) - Body groundAlways10 to 14 V
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
2.CHECK HARNESS AND CONNECTOR (GROUND CIRCUIT)
Pre-Crash Safety System - Power Source Circuit. PRE-CRASH SAFETY. Lexus IS250 IS220d GSE20 ALE20

Disconnect the negative (-) terminal cable from the battery.

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

  • Standard resistance:
  • Tester ConnectionConditionSpecified Condition
    O38-18 (PGND) - Body groundAlwaysBelow 1 Ω
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
REPLACE SEAT BELT CONTROL ECU