Excessive Dump Time

Test 1:

Tests 2 Through 4:

Symptom:
EXCESSIVE DUMP TIME

When Monitored and Set Condition:
EXCESSIVE DUMP TIME - EBC 2
When Monitored:
1. Brake pedal depressed (to enable antilock activity).
2. Wheel speed below 6 km/h (4 mph).
3. No 4WD sense signal input.
4. Wheel speed history ruling out any unusual events during the preceeding 15 seconds.

Set Condition:
Need for more than 24 dump pulses in response to the wheels that have gone to lock and is not recovering.

EXCESSIVE DUMP TIME - EBC 325
When Monitored:
1. Vehicle speed above 6 km/h (4 mph) for 9 seconds.
2. Vehicle in antilock control mode.

Set Condition:
Nine seconds of continuous dump activity in response to a wheel which has gone to lock and is not recovering.

POSSIBLE CAUSES
EXCESSIVE BRAKE PEDAL USE ON GRAVEL SURFACE
HCU/PUMP DEFECTIVE
BRAKE SYSTEM MECHANICALLY DEFECTIVE
LEAKY OR STUCK OPEN ISOLATION VALVE
LEAKY OR STUCK CLOSED DUMP VALVE
BAD PUMP MOTOR (EBC325 ONLY)
WHEEL SPEED SENSOR WIRING HARNESS INTERMITTENT DEFECT BELOW INTERMITTENT
SIGNAL DTC CRITERIA
LOW PRESSURE ACCUMULATOR PISTON STUCK IN ITS CONVENTIONAL BRAKING POSITION
INOPERATIVE 4WD SENSE CIRCUIT
PARKING BRAKE BEING APPLIED WHILE DRIVING ABOVE 6 KM/H (4 MPH)