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Data Link Connector No. 3 Inspection

NOTE: The vehicle's ECM uses ISO 9141-2 for communication. Terminal arrangement of DLC3 complies with SAE J1962 and matches ISO 9141-2 format.
  1. If display shows UNABLE TO CONNECT TO VEHICLE when you have connected cable of OBD II scan tool or hand-held tester to DLC3, turned ignition switch ON and operated scan tool, there is a problem on vehicle side or tool side. If communication is normal when tool is connected to another vehicle, go to next step. If communication is still impossible when tool is connected to another, problem is probably with hand-held tester or scan tool.
  2. Check DLC3 for loose or damaged terminals. Ensure DLC3 terminals are in correct position in connector. See Fig 1. If connector and terminals are okay, go to next step. If connector or terminals are defective, repair as necessary.
  3. Check voltage and resistance between ground and specified terminal on DLC3. See DATA LINK CONNECTOR NO. 3 VOLTAGE & RESISTANCE SPECIFICATIONS  table. See Fig 1. If voltage or resistance readings are not within specification, check wiring circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
    DATA LINK CONNECTOR NO. 3 VOLTAGE & RESISTANCE SPECIFICATIONS

    Terminal No. (Circuit) Specification Condition
    4 (Chassis Ground) - Body Ground 1 Ω Or Less Always
    5 (Signal Ground) - Body Ground 1 Ω Or Less Always
    7 (BUS Communication) Pulse Generation During Transmission
    16 (Battery Voltage) - Body Ground 9-14 V Always
    Fig 1: Identifying Data Link Connector No. 3 Terminals
    G99C52821Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002