Data Link Connector Diagnosis

Circuit Description
The Data Link Connector check is used to identity the cause of an inoperative scan tool. Possible faults include scan tool non-power up and lack of communication between the scan tool and the PCM. The DLC supplies power to the scan tool through CKT 40 to terminal 16. The ground to the scan tool is supplied through CKT 51 to terminal 5. The serial data (communication) is supplied to the scan tool through CKT 1807 to terminal 2.


Diagnostic Aids
Perform the Powertrain On Board Diagnostic System Check before performing this chart to help prevent misdiagnosis.

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.

3. Checking the voltage and ground supply to the scan tool.

4. Checking if the fault is power or ground circuit related.

5. Terminal 4 of the DLC connector is the ground circuit for scan tool data communications and terminal 5 is the power ground circuit for the scan tool.

6. If the fuse is blown check for a short to ground in CKT 40. If fuse is OK check for open in CKT 40 or lack of voltage to the fuse.

7. If communication is present between the scan tool and PCM then the fault is not present or was poor terminal contact at the DLC connector.

8. Checking if the fault is vehicle or scan tool related.