Data Link Connector Inspection

If Toyota hand-held tester or scan tool displays UNABLE TO CONNECT TO VEHICLE when hand-held tester or scan tool is connected to Data Link Connector No. 3 (DLC3), try hand-held tester or scan tool on another vehicle. If hand-held tester or scan tool operates on another vehicle, go to next step. If hand-held tester or scan tool does not operate on another vehicle, problem is probably with hand-held tester or scan tool.
Check voltage and resistance between ground and specified terminal on DLC3. See DATA LINK CONNECTOR VOLTAGE & RESISTANCE SPECIFICATIONS . See Fig 1. If voltage or resistance are not within specification, check wiring circuit. To identify circuits referenced in testing, see appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.

DATA LINK CONNECTOR VOLTAGE & RESISTANCE SPECIFICATIONS

Terminal No. (Circuit)

Specification

4 (Chassis Ground)

1 Ohm Or Less

5 (Signal Ground)

1 Ohm Or Less

7 (BUS Communication)

⁽¹⁾

16 (Battery Voltage)

9-14 Volts

⁽¹⁾	Pulse generation should exist during information transmission from Engine Control Module (ECM).

Fig 1: Identifying Data Link Connector Terminals