Service Check Signal Circuit Method

With the ignition switch off, connect the Honda PGM tester to the 16P DLC under the drivers side of the dashboard. See Figure .
Short the SCS circuit to body ground using the Honda PGM tester.
Turn the ignition switch on (II).
The blinking frequency indicates the DTC. DTCs are indicated by a series of long and short blinks. One long blink equals 10 short blinks. Add the long and short blinks together to determine the DTC. See Fig 1 . After determining the DTC, see DIAGNOSTIC TROUBLE CODE DEFINITIONS .
NOTE: If the DTC is not memorized, the ABS indicator will go off for 3.6 seconds, and then come back on.

NOTE: If the ABS indicator stays on, see TEST B: ABS INDICATOR DOES NOT GO OFF under SYSTEM TESTS.

NOTE: The system will not indicate the DTC unless the brake pedal is not pressed, the ignition switch is turned on (II) and the SCS circuit is shorted to body ground before the ignition switch is turned on (II).
Turn the ignition switch off.
Disconnect the Honda PGM tester from the DLC.

Fig 1: Identifying DTC Blinking Frequency

Courtesy of AMERICAN HONDA MOTOR CO., INC.