Failure Code [Dgh2Kb] Hydraulic Oil Temp Sensor Ground Fault - Komatsu PC88MR-10 Shop Manual

Failure code [DGH2KB] Hydraulic Oil Temp Sensor Ground Fault

DGH2KB-400-A-Z0-A)
Action level Failure code
L01 DGH2KB
Detail of Signal voltage of hydraulic oil temperature sensor circuit is below 1 V, so pump controller
failure determines that circuit shorts.
Action of
If cause of failure disappears, machine becomes normal by itself.
controller
Problem on
Hydraulic oil temperature gauge indicates 50°C.
machine
Signal voltage from hydraulic oil temperature sensor can be checked with monitoring
function.
(Code: 04402)
Method of reproducing failure code: Start engine.
Related
Loosen the oil filler cap of the hydraulic tank to release the pressure in the
information
hydraulic tank. For details, see Testing and adjusting "Releasing remaining
pressure in hydraulic circuit" when checking and replacing hydraulic oil
temperature 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 hydraulic oil
temperature sensor
1
(Internal open or short
circuit)
Open circuit, short
circuit, or ground fault in
2
wiring harness
Short circuit or ground
3
fault in wiring harness
Ground fault in wiring
harness
4
(Contact with ground
circuit)
Pump controller is
5
defective.
PC88MR-10
Hydraulic Oil Temperature Sensor Ground Fault
Failure
(Pump controller system)
Procedure, measuring location, criteria, and remarks
1. Turn starting switch to OFF position.
2. Disconnect connector P22 and connect T-adapter to male side.
Between P22 (male) (1) and (2)
a Temperature-resistance
Resistance
characteristics of oil temperature
sensor
Between P22 (male) (2) and ground
1. Turn starting switch to OFF position.
2. Disconnect connector P22 and connect T-adapter to female side.
3. Turn starting switch to ON position.
a If voltage is 0 V, wiring harness has open circuit, ground fault, or short
circuit, and if voltage is 24 V, wiring harness has hot short circuit.
a Voltage of approx. 5 V is applied to temperature sensor signal circuits
through resistance in pump controller.
Voltage Between P22 (female) (1) and (2)
1. Turn starting switch to OFF position.
2. Disconnect connector CP01 and connect T-adapter to female side.
a Use Temperature-Resistance characteristics table for troubleshooting on
cause 1 as resistance criteria.
a If resistance is 1 Mz or higher, wiring harness has open circuit. If
resistance is 1 z or below, wiring harness has short circuit.
Between CP01 (female) (28) and (46)
Resistance
Between CP01 (female) (28) and ground
a If no failure is found by check on cause 2, this check is not required.
1. Turn starting switch to OFF position.
2. Disconnect connectors CP01 and P22, and connect T-adapter to either
female side.
Between ground and CP01 (female) (28) or P22
Resistance
(female) (2)
If cause is not found by above checks, pump controller is defective.
(Since this is an internal defect, troubleshooting cannot be performed.)
40 Troubleshooting
Troubleshooting by failure code (Display of code)
(PC88MR-
Approx. 90
10°C
kz
Approx. 35
30°C
kz
Approx. 6.5
80°C
kz
Approx. 3.7
100°C
kz
Min. 1 Mz
Approx. 5 V
3.5 to 90 kz
Min. 1 Mz
Min. 1 Mz
40-299