Failure Code [Ca2556] Grid Htr Relay Short Circuit Error - Komatsu PC200-8M0 Shop Manual

SEN06134-00

Failure code [CA2556] Grid Htr Relay Short Circuit Error

Action
Failure code
level
L01 CA2556
q
Detail of failure Short circuit is detected in drive circuit (primary circuit) of preheater relay.
Action of con-
q
None in particular
troller
q
Problem on Intake air heater does not work in auto preheating (degraded starting performance at low temper-
machine ature and emission of white smokes)
q
Temperature sensed by boost temperature sensor can be checked with monitoring function.
(Code: 18500 )
q
Method of reproducing failure code: Turn starting switch to ON position (when boost temperature
Related infor- is below -4 °C)
q
mation Troubleshooting for this failure code covers circuit starting from engine controller to primary (coil)
side of preheater relay R18.
q
For troubleshooting related to heater relay and secondary side of preheater relay R18, see E-2 in
E-mode.
Cause
Defective wiring harness connec-
1
tor
2 Defective preheater relay R18
3 Ground fault in wiring harness
4 Short circuit in wiring harness
5 Defective engine controller
54
40-302

Failure code [CA2556] Grid Htr Relay Short Circuit Error

Intake air Heater Relay Short Circuit
Failure
(Engine controller system)
Procedure, measuring location, criteria and remarks
See descriptions of wiring harness and connectors in "c: Electrical equipment"
in "Checks before troubleshooting" of "General information on troubleshoot-
ing", and check them.
1. Turn starting switch to OFF position.
2. Disconnect relay R18, and connect T-adapters to male side.
Between R18 (male) (1) and (2)
1. Turn starting switch to OFF position.
2. Replace relay R18 with another one.
3. Turn starting switch to ON position.
If this failure code disappears, original preheater relay R18 is defective.
1. Turn starting switch to OFF position.
2. Disconnect connector CE02 and relay R18, and connect T-adapters to
either female side.
Between CE02 (female) (40) or R18 (female) (1)
and ground
1. Turn starting switch to OFF position.
2. Disconnect connector CE02 and relay R18, and connect T-adapters to
female side of CE02.
a Check with multimeter in continuity mode.
Between CE02 (female) (40) and each pin other
than (40)
If no failure is found by above checks, engine controller is defective. (Since
this is an internal defect, troubleshooting cannot be performed.)
302 Troubleshooting by failure code, Part 2
Resistance
Resistance Min. 1 Mz
No continuity
(No sound is heard)
PC200, 200LC, 220, 220LC-8M0
200 to
400 z