Checking DLC Wiring: Notes
Black DLC is for scan tester power and ground circuits. White DLC is for scan tester rapid data transfer circuits. All systems that can be monitored with a scan tester (ECM, automatic transmission, ABS, etc.) are monitored through the same White DLC. Rapid data transfer circuits for all systems are connected in parallel to terminals "K" and "L", which serve as common junction blocks. See Figure or Figure . Ground terminal of White DLC is connected to terminal "L". Power terminal of White DLC is connected to terminal "K".