Diagnosis System

WARNING: This page is about a different car, the 2009 Lexus IS 350 and 2009 Lexus IS 250. However, it is still accessible from the selected car via links, so may be relevant.

DESCRIPTION
1. The power window control system data can be read from the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the Techstream to check for malfunctions and perform repairs.

CHECK DLC3

Fig 1: Checking DLC3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

The vehicle uses ISO 15765-4 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.

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
CANH (6) - CANL (14)	HIGH-level CAN bus line	Engine switch OFF	54 to 69 Ω
CANH (6) - Battery positive (+)	HIGH-level CAN bus line	Engine switch OFF	1 MΩ or higher
CANH (6) - CG (4)	HIGH-level CAN bus line	Engine switch OFF	1 kΩ or higher
CANL (14) - Battery positive (+)	LOW-level CAN bus line	Engine switch OFF	1 MΩ or higher
CANL (14) - CG (4)	LOW-level CAN bus line	Engine switch OFF	1 kΩ or higher

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 the Techstream to the DLC3, turn the engine 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
1. Measure the battery voltage.
  Standard Voltage
  
  11 to 14 V
  
  If the voltage is below 11 V, recharge or replace the battery.