Failure Code [Dhpama] Front Pump Press Sens Defective Function - Komatsu PC88MR-10 Shop Manual

Failure code [DHPAMA] Front Pump Press Sens Defective
Function
(PC88MR-DHPAMA-400-A-Z0-A)
Action level Failure code
L01 DHPAMA
Detail of
Signal voltage of pump pressure sensor circuit is below 0.3 V or above 4.5 V.
failure
Controls pump taking pump pressure to be 0 MPa {0 kg/cm
Action of
If cause of failure disappears, machine becomes normal by itself.
controller
Automatic travel speed selector function does not work.
Problem on
Straight travel performance or steering performance lowers.
machine
a If 5 V circuit (3) and ground circuit (1) of pressure sensor are connected inversely,
pressure sensor will break. Accordingly, take extreme care when checking.
As T-adapter for pump controller connector is "socket-type box", operating voltage cannot
be measured at pump controller connector.
Pump pressure can be checked by using monitoring function.
(Code: 01100)
Related
Method of reproducing failure code: Turn starting switch to ON position or start engine.
information
Loosen the oil filler cap of the hydraulic tank to release the pressure in the
hydraulic tank. For details, see Testing and adjusting "Releasing remaining
pressure in hydraulic circuit" when checking and replacing oil pressure sensor.
With monitoring function (Code: 04401), check that hydraulic oil temperature is 40°
C or lower and cool enough not to burn.
No. Cause
Defective 5 V sensor
1
power supply 1 system
Defective pump
pressure sensor
2
(internal defect)
PC88MR-10
Front Pump Pressure Sensor Defective Function
Failure
(Pump controller system)
Procedure, measuring location, criteria, and remarks
If failure code [DA25KP] is also displayed, perform troubleshooting for it first.
1. Turn starting switch to OFF position.
2. Disconnect connector P25, and connect T-adapter to female side.
3. Turn starting switch to ON position.
a If power supply voltage is abnormal, proceed to check on cause 3.
Voltage Between P25 (female) (3) and (1)
1. Turn starting switch to OFF position.
2. Insert T-adapter into connector P25.
3. Turn starting switch to ON position.
Voltage Between P25 (2) and (1)
a If power supply voltage is normal and sensor output voltage is abnormal, it
is difficult to judge whether cause of failure is defective sensor, ground
fault or hot short circuit in wiring harness. Check as below.
1. Turn starting switch to OFF position.
2. Replace connector P25 with connector P49 of other service pressure
sensor.
3. Turn starting switch to ON position and display "Abnormality Record"
screen of electrical system on machine monitor.
4. If E mark is not displayed for this failure code column, pump pressure
sensor is defective.
a After finishing test, restore connectors.
40 Troubleshooting
Troubleshooting by failure code (Display of code)
2 }.
Power
4.5 to 5.5 V
supply
Sensor
0.5 to 4.5 V
output
40-301