Diagnostic Mode

For a Mark 20 system to enter a diagnostic mode, vehicle speed must be below 10 km/h (6 mph), a "No Response" message will be displayed by the DRBIII(R). The following are characteristics of diagnostic mode:

• The amber ABS warning indicator will flash. If a hard trouble code is present, such as a Speed Sensor Circuit or Signal Failure trouble code or CAB Power Feed Circuit diagnostic trouble code, the ABS warning indicator will be illuminated without blinking until the diagnostic trouble code condition is corrected.
• Anti-lock operation is disabled.