LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2003 >> Highlander Limited, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self Diagnostics - V6 >> Scan Tool Problems >> Data Link Connector No. 3 Inspection
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Data Link Connector No. 3 Inspection

NOTE: The vehicle's ECM uses the ISO 9141-2 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.
  1. If the display shows UNABLE TO CONNECT TO VEHICLE when you have connected the cable of the OBD II scan tool or the hand-held tester to the DLC3, turned the ignition switch ON and operated the scan tool, there is a problem on the vehicle side or tool side. If the communication is normal when the tool is connected to another vehicle, go to next step. If the communication is still impossible when the tool is connected to another, problem is probably with hand-held tester or scan tool.
  2. Check the 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 DLC No. 3. 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
    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