ABS Control Unit
When checking for voltage at ABS control unit terminals, probe from rear of connector (harness side) to prevent damage to terminals. See Fig 1 .
ABS control unit has a self-diagnostic function to check hydraulic system operation. During diagnostic mode, ABS control unit activates hydraulic unit to reduce hydraulic pressure to right and left front wheels, and right and left rear wheels in sequence for .5 second each at 1.5-second intervals.
NOTE:
Before proceeding with hydraulic system test, verify battery is fully charged and ABS warning light goes out after engine is started. If ABS warning light stays on after engine is started, ABS control unit detects failure and will not activate hydraulic unit.