12-pin Diagnostic Port (Data Link Connector)

This page presents the wiring you would expect to find on a 12-pin diagnostic port connector like those found on 1G DSMs and EVO1-3 cars.

The following 3 wires are the wires used by the ECMLink datalogging cable.


The “front side” view is looking at the diagnostic connector in the car with the male pins pointing out at you. The “reverse side” view is looking at the connector end of our cable (looking “into” the female sockets).

Pin 12 should have connectivity to chassis ground. Check that this is true.

Pins 1 and 10 should not have connectivity to chassis ground and should not be connected with each other. Check that this is true.

Pins 1 and 10 should have connectivity back to pins on the ECU. Check that this is true.

For a 1G DSM ECU, pin 1 of the diagnostic connector should connect with pin 1 on the ECU. Pin 10 of the diagnostic connector should connect with pin 2 on the ECU. For 1G DSM ECU wiring information, view the 1G ECU Pinout document found on our ECU wiring page.

For an EVO1-3 ECU, pin 1 of the diagnostic connector should connect with pin 42 on the ECU. Pin 10 of the diagnostic connector should connect with pin 43 on the ECU. For EVO1-3 ECU wiring information, refer to this document put together by the fine folks at www.evocoupe.net.