Tire Pressure Warning Light Circuit

TIRE AND WHEEL: TIRE PRESSURE WARNING SYSTEM: Tire Pressure Warning Light Circuit

Tire Pressure Warning Light Circuit

DESCRIPTION

If the tire pressure warning ECU detects a disconnected connector or an open circuit between the tire pressure warning ECU and combination meter, the tire pressure warning light turns off 1 second after the ignition switch is turned ON, blinks for 1 minute, and then remains on.

WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE:
- When replacing the tire pressure warning ECU, read the transmitter IDs stored in the old ECU using a Techstream and write them down before removal.
- It is necessary to perform registration Programming and Relearning of the transmitter IDs into the tire pressure warning ECU after the ECU has been replaced.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECU AND BODY GROUND)




(a) Disconnect the D78 ECU connector.
(b) Disconnect the D1 meter connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
2. INSPECT COMBINATION METER




(a) Disconnect the D78 ECU connector.
(b) Turn the ignition switch to ON, and check if the tire pressure warning light illuminates.
OK:
Tire pressure warning light illuminates

Result





C -- REPLACE COMBINATION METER
B -- REPLACE COMBINATION METER
A -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE