ECU Power Source Circuit

ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM: ECU Power Source Circuit
- ECU Power Source Circuit

DESCRIPTION

This circuit provides power to operate the transponder key ECU.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
If the transponder key ECU is replaced, register the key and ECU communication ID.

PROCEDURE

1. INSPECT FUSE (IGN FUSE)





(a) Remove the IGN fuse.

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

Standard resistance:





(1) Reinstall the IGN fuse.

NG -- CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE
OK -- Continue to next step.

2. INSPECT FUSE (ECU-B FUSE)





(a) Remove the ECU-B fuse.

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

Standard resistance:





(1) Reinstall the ECU-B fuse.

NG -- CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - BATTERY)

(a) Disconnect the E79 transponder key ECU connector.





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

Standard voltage:





(c) Reconnect the transponder key ECU connector.

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

4. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - BODY GROUND)

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





Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Symptom Related Diagnostic Procedures