Rear Isolation Solenoid Open

Tests 1 Through 3:

Test 4:

Symptom:
REAR ISOLATION SOLENOID OPEN - EBC 2

When Monitored and Set Condition:
REAR ISOLATION SOLENOID OPEN - EBC 2

When Monitored:
1. ABS power relay closed.
2. Valve command for rear isolation solenoid not present (not trying to turn the valve on).

Set Condition:
3. Low feedback voltage from the low side of solenoid.
4. Criteria 1-3 satisfied for over 40 consecutive controller checks spaced 5 milliseconds (ms) apart.

POSSIBLE CAUSES
HCU 4-WAY CONNECTOR OBSERVABLE DEFECT
HCU 4-WAY CONNECTOR/HARNESS OBSERVABLE DEFECT
HYDRAULIC CONTROL UNIT ASSEMBLY DEFECTIVE
REAR ISOLATION VALVE CONTROL CIRCUIT SHORT TO GROUND