DTC 53 Isolation Solenoid Shorted - EBC 2

NAME OF CODE:
Rear Isolation Solenoid Shorted
Rear Dump Solenoid Shorted

SET CONDITION
1. ABS power relay closed.
2. Valve command for a particular solenoid present (trying to turn the valve on).
3. High feedback voltage from low side of solenoid.
4. Criteria 1-3 satisfied for over 200 ms.

THEORY OF OPERATION:
Vehicle battery voltage is applied to the high side of the two solenoid coils in the hydraulic assembly by the ABS power relay whenever valve activity may be required. Each solenoid is energized by turning on the CAB output driver transistor to short the low side of the coil to ground. Whenever a driver transistor is turned on, the feedback voltage should be low. If not, and the problem persists long enough to rule out noise input, the Solenoid Shorted code is set.

POSSIBLE CAUSES:
- Shorted solenoid
- Short to vehicle battery voltage or to 5-volt in the solenoid feedback to the CAB
- Anything that keeps solenoid feedback voltage high when a particular solenoid is supposed to be energized