Diesel Data: Automotive Repair

ECU Power Source Circuit








THEFT DETERRENT: THEFT DETERRENT SYSTEM: ECU Power Source Circuit

ECU Power Source Circuit

DESCRIPTION

This circuit provides power for multiplex network body ECU operation.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (ECU-B)
(a) Remove the ECU-B fuse from the engine room R/B and J/B.
(b) Check the resistance.
Standard resistance:
Below 1 Ohms

NG -- REPLACE FUSE
OK -- Continue to next step.

2. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (MULTIPLEX NETWORK BODY ECU) (POWER SOURCE)





(a) Disconnect the ID J/B connector.
(b) Check the voltage between the wire harness side connector and the body ground.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. CHECK WIRE HARNESS (INSTRUMENT PANEL J/B ASSEMBLY - BODY GROUND)





(a) Disconnect the IF and IM J/B connectors.
(b) Check the resistance between the wire harness side connector and the body ground.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE