U5 Verify Diagnostic Circuit Is Intact

- Key OFF.

- Measure resistance between the pin for Circuit 571 (BK/O) in the ABS diagnostic connector and 60-pin breakout box Pin 4.

- Is the resistance less than 2 ohms?

YES -- Antilock brake control module appears incapable of performing diagnostics. Replace antilock brake control module. Repeat PC4.

NO -- Find and service cause of high resistance in Circuit 571 (BK/O). Repeat PC4.