Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Diagnosis System
- DESCRIPTION
- Push-button start function data and the Diagnostic Trouble Codes (DTCs) can be read through the Data Link Connector 3 (DLC3) of the vehicle. When the function seems to be malfunctioning, use Techstream to check for malfunctions and perform repairs.
- CHECK DLC3
HINT:
The ECU uses ISO 15765-4 communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
TERMINAL DESCRIPTION AND SPECIFIED CONDITIONSymbols (Terminal No.) Terminal Description Condition Specified Condition CG (4) - Body ground Chassis ground Always Below 1 Ω SG (5) - Body ground Signal ground Always Below 1 Ω SIL (7) - SG (5) Bus "+" line During transmission Pulse generation BAT (16) - Body ground Battery positive Always 10 to 14 V CANH (6) - CANL (14) CAN bus line Power Switch OFF* 56 to 69 Ω CANH (6) - CG (4) HIGH-level CAN bus line Power Switch OFF* 200 Ω or more CANL (14) - CG (4) LOW-level CAN bus line Power Switch OFF* 200 Ω or more CANH (6) - BAT (16) HIGH-level CAN bus line Power Switch OFF* 6 kΩ or more CANL (14) - BAT (16) LOW-level CAN bus line Power Switch OFF* 6 kΩ or more NOTE: *: Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power switch, any other switches or the doors.If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.
HINT:
Connect the cable of Techstream to the DLC3, turn the power switch on (IG) and attempt to use the tester. If the display indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester.
- If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle.
- If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the Service Department listed in the tester's instruction manual.
- INSPECT BATTERY VOLTAGE
Standard voltage:
11 to 14 V
If the voltage is below 11V, recharge or replace the battery before proceeding.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.