Without Scan Tool

Flash code diagnosis can only be used to identify codes in the EBCM history. The flash code diagnostic mode cannot be initiated if the Anti-Lock warning lamp is on steady.
To initiate flash code diagnostics, ground pin ``H'' of the diagnostic connector, then turn ignition on. Flash Code Diagnostics will remain on as long as pin ``H'' is grounded, serial data line communication has not been initiated, and vehicle speed is less than 4 mph.

Fig. 5 ABS Flash Code Sequence:

Approximately three seconds after ALDL has been grounded, the EBCM will begin flashing the Anti-Lock Indicator Lamp in flash code sequence. The flash code sequence Fig. 5 will begin with Code 12 flashing three times to signal the beginning of the trouble code display. Each stored code will than be flashed three times. After all codes have been displayed, the sequence will repeat, starting with Code 12.
Current Codes 41, 45, 55, 61 and 63 can only be read using the TECH 1 diagnostic computer. If these codes are present as history codes only, they can be read through flash code diagnosis.

When performing diagnosis on 1993 Eldorado and Seville models, refer to SCHEMATIC DIAGRAMS for wiring circuits, and DIAGNOSTIC CHARTS for CODE CHARTS, SYMPTOM CHARTS A, B, C and D