Failure Code [Ca2556] Intake Heater Relay Short Circuit Error - Komatsu WA250-6 Shop Manual

SEN03843-00

Failure code [CA2556] Intake heater relay short circuit error

Action code Failure code
E01 CA2556
Contents of
• There is short circuit in intake air heater relay.
trouble
Action of
• None in particular.
controller
Problem that
• Intake air heater does not function. (Poor starting performance, white exhaust smoke at low temper-
appears on
ature)
machine
• The input state (boost temperature) can be checked with the monitoring function (Code : ENGINE,
Related 18500, CHG TEMP)
information
• Method of reproducing failure code: Turn the starting switch ON when boost temperature is –4°C or
less.
Defective heater relay
1
(Internal short circuit)
Ground fault in wiring har-
2 ness
(Contact with ground circuit)
Possible causes
and standard
value in normal
state
Short circuit in wiring har-
3 ness
(with another wiring harness)
Defective wiring harness
4
connector
5 Defective engine controller
54
40-330
Intake heater relay short circuit error
Trouble
(Engine controller system)
Causes
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON. (Test relay unit).
a Prepare with starting switch OFF, then turn starting switch ON
and carry out troubleshooting. (Test by replacing relay unit.)
When heater relay is replaced with a relay of the same type, if the
condition becomes normal, the heater relay is defective.
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Wiring harness between EC2 (female) (40) –
E06
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
Wiring harness among all pins between EC2
(female) (40) – EC2 (female) (E06, too, is
disconnected.)
Connecting parts among heater relay, engine unit wiring harness,
and engine controller are suspected. Inspect them directly.
• Loose connector, broken lock, broken seal
• Corrosive, bent, broken, forced-in, or extended pin
• Humidity in connector, entry of dirt or dust, poor insulation
a Prepare with starting switch OFF, then carry out troubleshooting
without turning starting switch ON.
330 Troubleshooting by failure code (Display of code), Part 3
Failure code [CA2556] Intake heater relay short circuit error
Standard value in normal state/Remarks on troubleshooting
Between E06 and ground
EC2 (female)
Between (40) and ground
1
Resistance
300 – 600 z
Resis- Min.
tance 100 kz
Resis- Min.
tance 100 kz
Resistance
300 – 600 z
WA250, 250PZ-6