Diagnosis System

DESCRIPTION
1. Push button start system data and its Diagnostic Trouble Code (DTCs) can be read in the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the hand-held tester to check for malfunctions and perform repairs.

CHECK DLC3

The vehicle's ECU uses the ISO 9141-2 communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9142-2 format.

Fig 1: Identifying DLC3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

DLC3

Symbols (Terminal No.)	Terminal Description	Condition	Specified Condition
SIL (7) - SG (5)	Bus "+" line	During transmission	Pulse generation
CG (4) - Body ground	Chassis ground	Always	Below 1 Ω
SG (5) - Body ground	Signal ground	Always	Below 1 Ω
BAT (16) - Body ground	Battery positive	Always	11 to 14 V

HINT:

When troubleshooting the push-button function using the hand-held tester with the engine switch off, connect the hand-held tester to the vehicle and repeat turning any of the courtesy light switches on and off until communication between the tester and the vehicle begins (the interval between ON and OFF should be less than 1.5 sec.).
Connect the cable of the hand-held tester to the DLC3, turn the engine switch on (IG) and attempt to use the hand-held tester. If the display informs that a communication error has occurred, there is a problem either with the vehicle or with the tester.

Fig 2: Connecting Hand-Held Tester To DLC3
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
If the communication is normal when the tester is connected to another vehicle, inspect the DLC3 on the original vehicle.
If the communication is still impossible when the tester is connected to another vehicle, the problem is probably in the tester itself. Consult the Service Department listed in the tester's instruction manual.

INSPECT BATTERY VOLTAGE
Standard: 11 to 14 V

If voltage is below 11 V, recharge the battery before proceeding.