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ECU Power Source Circuit





TIRE AND WHEEL: TIRE PRESSURE WARNING SYSTEM: ECU Power Source Circuit
- ECU Power Source Circuit

DESCRIPTION

This is the power source for the tire pressure warning ECU.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
It is necessary to register the transmitter IDs after replacing a tire pressure warning valve and transmitter and/or the tire pressure warning ECU Programming and Relearning.

PROCEDURE

1. INSPECT FUSE (ECU-IG1)

(a) Remove the ECU-IG1 fuse from the instrument panel junction block.

(b) Measure the resistance of the fuse.

Standard resistance:

Below 1 Ohms

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

2. INSPECT IG1 RELAY

(a) Remove the IG1 relay from the instrument panel junction block.





(b) Measure the resistance of the relay.

Standard resistance:





NG -- REPLACE IG1 RELAY
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (ECU - BATTERY AND BODY GROUND)





(a) Disconnect the E56 ECU connector.

(b) Measure the voltage of the wire harness side connector.

Standard voltage:





(c) Measure the resistance of the wire harness side connector.

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

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