AIRBAG SYSTEM Diagnosis Circuit
DESCRIPTION
DTC output mode is set by connecting terminals TC and CG of the DLC3.
DTCs are displayed by the blinking of the SRS warning light.
Tech Tips
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When each warning light stays blinking, a ground short in the wiring of terminal TC of the DLC3 or an internal ground short in each ECU is suspected.
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A DTC output mode signal is transmitted through CAN communication system to each ECU including the center airbag sensor assembly. Thus when all systems do not enter DTC output mode, there may be a hybrid vehicle control ECU malfunction.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
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CHECK CAN COMMUNICATION SYSTEM
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for LHD:
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Check if a CAN communication system DTC is output Click here.
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for RHD:
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Check if a CAN communication system DTC is output Click here.
Result Result Proceed to DTC is output (for LHD) A DTC is output (for RHD) B DTC is not output C -
A 
GO TO CAN COMMUNICATION SYSTEM Click here
B
GO TO CAN COMMUNICATION SYSTEM Click here
C 
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CHECK HARNESS AND CONNECTOR (DLC3 - HYBRID VEHICLE CONTROL ECU)
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Turn the power switch OFF.
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Disconnect the A77 hybrid vehicle control ECU connector.
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Measure the resistance according to the value(s) in the table below.
Standard resistance Tester Connection Condition Specified Condition L31-13 (TC) - A77-24 (TC) Always Below 1 Ω
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
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CHECK HARNESS AND CONNECTOR (DLC3 - BODY GROUND)
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Measure the resistance according to the value(s) in the table below.
Standard resistance Tester Connection Condition Specified Condition L31-4 (CG) - Body ground Always Below 1 Ω
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
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CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - BODY GROUND)
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Measure the resistance according to the value(s) in the table below.
Standard resistance Tester Connection Condition Specified Condition A77-24 (TC) - Body ground Always 1 MΩ or higher
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR OR EACH ECU
OK 
REPLACE CENTER AIRBAG SENSOR ASSEMBLY Click here
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