TERMINALS OF ECU
1. CHECK TIRE PRESSURE WARNING ECU AND RECEIVER
(a) Disconnect the T14 tire pressure warning ECU and receiver connector and measure the voltage and resistance on the wire harness side.
Text in Illustration
*A |
w/o Wireless Door Lock System |
*B |
w/o Smart Key System with Wireless Door Lock System |
*C |
w/ Smart Key System |
*a |
Front view of wire harness connector (to Tire Pressure Warning ECU and Receiver) |
Terminal No. (Symbol) |
Wiring Color |
Terminal Description |
Condition |
Specified Condition |
---|---|---|---|---|
T14-1 (IG) - T14-12 (GND) |
LG - W-B |
IG power source |
Ignition switch ON |
10 to 16 V |
T14-12 (GND) - Body ground |
W-B - Body ground |
Ground |
Always |
Below 1 Ω |
Terminal No. (Symbol) |
Wiring Color |
Terminal Description |
Condition |
Specified Condition |
---|---|---|---|---|
T25-1 (IG) - T25-12 (GND) |
LG - W-B |
IG power source |
Ignition switch ON |
10 to 16 V |
T25-7 (+B) - T25-12 (GND |
BE - W-B |
Power supply (from battery) |
Always |
10 to 16 V |
T25-12 (GND) - Body ground |
W-B - Body ground |
Ground |
Always |
Below 1 Ω |
Terminal No. (Symbol) |
Wiring Color |
Terminal Description |
Condition |
Specified Condition |
---|---|---|---|---|
T24-1 (IG) - T24-12 (GND) |
LG - W-B |
IG power source |
Ignition switch ON |
10 to 16 V |
T24-7 (+B) - T24-12 (GND) |
BE - W-B |
Power supply (from battery) |
Always |
10 to 16 V |
T24-12 (GND) - Body ground*1 |
W-B - Body ground |
Ground |
Always |
Below 1 Ω |
(b) Connect the T14*1, T25*2, T24*3 tire pressure warning ECU and receiver connector.
(c) Measure the voltage and resistance according to the value(s) in the table below. If the result is not as specified, the ECU may be malfunctioning.
HINT:
Measure the values on the wire harness side while the connector is connected.
Terminal No. (Symbol) |
Wiring Color |
Terminal Description |
Condition |
Specified Condition |
---|---|---|---|---|
T14-3 (CLSW) - T14-12 (GND)*1 T25-3 (CLSW) - T25-12 (GND)*2 T24-3 (CLSW) - T24-12 (GND)*3 |
R - W-B |
Tire pressure warning reset switch |
|
Below 1.5 V |
|
8 to 15 V |
|||
T14-4 (RDA) - T14-12 (GND)*1 T25-4 (RDA) - T25-12 (GND)*2 T24-4 (RDA) - T24-12 (GND)*3 |
B - W-B |
Output signals |
Ignition switch ON |
Pulse generation (see waveform 1) |
T14-5 (PRG) - T14-12 (GND)*1 T25-5 (PRG) - T25-12 (GND)*2 T24-5 (PRG) - T24-12 (GND)*3 |
GR - W-B |
Input signals |
Ignition switch ON |
Pulse generation (see waveform 1) |
(d) Using an oscilloscope, check waveform 1.
Waveform 1:
Item |
Contents |
---|---|
Terminal |
T14-4 (RDA) - T14-12 (GND)*1 T25-4 (RDA) - T25-12 (GND)*2 T24-4 (RDA) - T24-12 (GND)*3 T14-5 (PRG) - T14-12 (GND)*1 T25-5 (PRG) - T25-12 (GND)*2 T24-5 (PRG) - T24-12 (GND)*3 |
Tool setting |
5 V/DIV., 5 ms./DIV. |
Vehicle condition |
Ignition switch ON |
*a |
Example |
*b |
GND |
HINT:
The waveform shown in the illustration is an example. If the tester displays a waveform that alternates between high and low, where high is a voltage that is between the IG power source voltage and a voltage 2.2 V lower than the IG power source voltage, and where low is a voltage of between 0 and 1.2 V, the ECU can be judged normal.
Electronic Circuit Inspection Procedure
ELECTRONIC CIRCUIT INSPECTION PROCEDURE
1. BASIC INSPECTION
(a) WHEN MEASURING RESISTANCE OF ELECTRONIC PARTS
(1) Unless otherwise stated, all resistance measurements should be made at an
ambient temperature of 20°C (68°F). Resistance measurements may be inaccurate if
measured at high tempe ...
How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT
HINT:
The ECM of this system is connected to the CAN communication system.
Therefore, before starting troubleshooting, make sure to check that there
is no trouble in the CAN and multiplex communication system.
*: Use the Techstream.
PROCEDURE
...
System Diagram
SYSTEM DIAGRAM
Communication Table
Sender
Receiver
Signal
Line
ECM
Millimeter Wave Radar Sensor Assembly
Cruise control operation signal
Accelerator pedal idle position signal
Accel overr ...