Tech Tips
Date: September 5, 2014

TT 97-14-02
2004 and Newer Vehicles – Damage to Data Link Connector
(DLC) from Aftermarket Devices (Cannot Communicate with
Vehicle OBD System)

The DLC is intended for use with diagnostic scan tools and by emissions testing stations. However,
aftermarket devices (i.e., drive data recorders) that connect to the DLC have now become available.
If any such accessory device installed in the DLC is bumped by a driver’s leg or is mis-aligned and then
forced onto the DLC, this can unseat (push-back) or cause damage to one or more terminal pins.
Potential Concerns:
• Customer states they were turned-away from a state required emissions check because the test
station equipment could not communicate with the vehicle OBD system.
• Customer states that another repair shop was unable to communicate with the vehicle OBD system
using a generic and/or VAS scan tool.
Note:

For these concerns an inspection of the DLC is recommended even if a VAS scan tool
functions normally (generic scan tools and emissions test stations may have shorter pins).

Diagnosis Tip:
• Visually check for any damage at the DLC. Check each terminal for a pushed-back condition or
looseness in the connector body. A pin-drag check may also be necessary.
Repair:
• Ensure any pushed-back pins are fully seated and retained properly in the connector body. Any
damaged pins (loose, bent, or deformed) should be replaced.
• Following a repair to the DLC, verify communication with the vehicle using a scan tool.

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