Check tire pressure warning ecu
HINT: Inspect the connectors from the back side while the connectors are connected.

(a) Disconnect the tire pressure warning antenna and receiver connector.
(b) Measure the voltage according to the value(s) in the table below.

(c) Connect the tire pressure warning antenna and receiver connector.
(d) Measure the voltage and resistance according to the value(s) in the table below. If the result is not as specified, the ECU may have a malfunction.

(e) Using an oscilloscope, check the waveform 1.
(1) Waveform 1 (Reference)

(2) Waveform 2 (Reference)
Problem symptoms table
Diagnosis systemShort to B+ in Driver Side Squib Circuit
DTC B0103/12 Short to B+ in Driver Side Squib Circuit
DESCRIPTION
The driver side squib circuit consists of the center airbag sensor assembly,
the spiral cable and the
steering pad.
The circuit instructs the SRS to deploy when deployment conditions are met.
DTC B0103/12 is recorded when a ...
Data list / active test
HINT:
By accessing the DATA LIST displayed by the intelligent
tester, you can perform such functions as reading the values
of switches and sensors without removing any parts. Reading
the DATA LIST as the first step in troubleshooting is one
method to shorten labor time.
1. DATA LIST FOR OCCUPA ...
Uniform Tire Quality Grading
This information has been prepared in accordance with regulations
issued by the National Highway Traffic Safety Administration of the
U.S. Department of Transportation.
It provides the purchasers and/or prospective purchasers of Toyota
vehicles with information on uniform tire quality grading. ...