Circuit Description
The data link connector (DLC) is a standardized 16 cavity connector. Connector design and location is dictated by an industry wide standard, and is required to provide the following:
| • | Scan tool power battery positive voltage at terminal 16. |
| • | Scan tool power ground at terminal 4. |
| • | Common signal ground at terminal 5. |
The scan tool will power up with the ignition OFF. Some modules however, will not communicate unless the ignition is ON and the power mode master (PMM) module sends the appropriate power mode message.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Data Link Connector Schematics Connector End View Reference: Computer/Integrating Systems Connector End Views | |||
1 | Test the battery positive voltage circuit of the DLC for an open or a short to ground. Refer to Circuit Testing or Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 2 | |
2 | Test the ground circuit from pin 4 of the DLC for an open or high resistance. Refer to Circuit Testing or Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 3 | |
3 | Inspect for poor connections and terminal tension at the DLC. Refer to Testing for Intermittent Conditions and Poor Connections or Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 4 | |
The scan tool may be malfunctioning. Refer to the scan tool user guide. Did you obtain a properly operating scan tool? | Go to Step 1 | -- | |
