Power Source Circuit

PRE-COLLISION: PRE-COLLISION SYSTEM: Power Source Circuit
- Power Source Circuit

DESCRIPTION

This circuit supplies power to the seat belt control ECU.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (GND CIRCUIT)

(a) Disconnect the seat belt control ECU connector.





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

Standard Resistance:





Text in Illustration





(c) Reconnect the seat belt control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (IG1 CIRCUIT)

(a) Disconnect the seat belt control ECU connector.





(b) Turn the power switch on (IG).

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

Standard Voltage:





Text in Illustration





(d) Reconnect the seat belt control ECU connector.

NG -- INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (+B CIRCUIT)

(a) Disconnect the seat belt control ECU connector.





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

Standard Voltage:





Text in Illustration





(c) Reconnect the seat belt control ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (+B CIRCUIT)

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Pre-Collision System

4. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly Removal.





Text in Illustration





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

Standard Resistance:





(c) Reinstall the instrument panel junction block assembly.

NG -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Removal
OK -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - SEAT BELT CONTROL ECU)

(a) Disconnect the instrument panel junction block assembly connector.

(b) Disconnect the seat belt control ECU connector.

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

Standard Resistance:





(d) Reconnect the seat belt control ECU connector.

(e) Reconnect the instrument panel junction block assembly connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - SEAT BELT CONTROL ECU)
OK -- Continue to next step.

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

(a) Disconnect the instrument panel junction block assembly connector.

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

Standard Resistance:





(c) Reconnect the instrument panel junction block assembly connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BODY GROUND)
OK -- Continue to next step.

7. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK - POWER MANAGEMENT ECU)

(a) Disconnect the instrument panel junction block assembly connector.

(b) Disconnect the power management control ECU connector.

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

Standard Resistance:





(d) Reconnect the power management control ECU connector.

(e) Reconnect the instrument panel junction block assembly connector.

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

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