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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 J1972 and matches the ISO 9141-2 format.
  1. If your display shows UNABLE TO CONNECT TO VEHICLE when you have connected the cable of the hand-held tester or OBD II scan tool 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 communication is normal when the tool is connected to another vehicle, go to next step. If communication is still not possible when the tool is connected to another vehicle, the problem is probably in the tool itself, so consult the service department listed in the tool's instruction manual.
  2. Check the DLC3 for loose or damaged terminals. Ensure the DLC3 terminals are in correct position in connector. See Figure. 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 the DLC3. See DLC3 VOLTAGE & RESISTANCE SPECIFICATIONS  table. If voltage or resistance readings are not within specification, check wiring circuit. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
DLC3 VOLTAGE & RESISTANCE SPECIFICATIONS

Terminal No. (Circuit) Specification Condition
2 (BUS Communication) Pulse Generation During Transmission
4 (Chassis Ground) - Body Ground Less Than 1 Ω Always
5 (Signal Ground) - Body Ground Less Than 1 Ω Always
16 (Battery Voltage) - Body Ground 9-14 V Always