Failure Code [Dazqkr] Can2 Defective Communication (A/C Ecu) - Komatsu PC88MR-10 Shop Manual

Failure code [DAZQKR] CAN2 Defective Communication (A/C ECU)

DAZQKR-400-A-Z0-A)
Action level Failure code
DAZQKR
L01
Detail of In CAN communication 2 line (KOMNET/c), machine monitor cannot recognize air
failure conditioner controller.
Action of
Retains information at time of occurrence of failure.
controller
Function to collect information from engine controller does not work.
(Failure codes and monitoring codes that are sent by engine controller)
Problem on
Air conditioner cannot be operated (air does not blow out).
machine
Display of air conditioner operation screen of machine monitor is not correct.
Method of reproducing failure code: Turn starting switch to ON position.
Start of CAN communication is recognized by each controller when ACC signal of starting
switch is received.
Four different failure codes, [DA2QKR], [DB2QKR], [D8AQKR], and [DAZQKR], are used
for defective CAN communication by CAN2, which are detected by machine monitor.
Related
When all of these four failure codes are displayed, there may be a ground fault, short
information
circuit, or hot short in wiring harness (CAN communication circuit).
Since each controller and machine monitor are connected directly to battery, they are
supplied with power even after starting switch is turned to OFF position.
Since signal of active CAN communication line is pulse voltage, it cannot be measured by
using multimeter.
No. Cause
Defective power supply
1 to air conditioner
controller
Defective CAN
terminating resistor
2
(internal open or short
circuit)
Open or short circuit in
3
wiring harness
PC88MR-10
CAN2 Defective Communication (Air Conditioner ECU)
Failure
(Detected by machine monitor) (Machine monitor system)
Procedure, measuring location, criteria, and remarks
a Perform troubleshooting shown in Chapter 80 "Troubleshooting of power
supply system".
1. Turn starting switch to OFF position.
2. Disconnect connectors CM02 and K02, and connect T-adapters to each
male side.
Between K02 (male) (A) and (B)
Resistance
Between CM02 (male) (7) and (9)
CAN communication line
a CAN terminating resistor of 120 z is also located in machine monitor. That
is, 2 CAN terminating resistors of 120 z are connected in parallel. When
circuit resistance is measured at connector of controller other than
machine monitor, if combined resistance is 60 z, wiring harness does not
have open circuit.
1. Turn starting switch to OFF position, and turn battery disconnect switch to
OFF position.
2. Disconnect related connectors and connect T-adapters to connectors to
be measured.
a If short circuit is found (resistance between 2 terminals is 1 z or below),
disconnect all CAN communication connectors of every controller and
check whether short circuit occurs between wiring harnesses or inside
controller.
Between CM02 (female) (8) and (9)
Between CE03 (female) (17) and (18)
Between CP01 (female) (45) and (64)
Resistance
Between AC01 (female) (9) and (10)
Between CK01 (female) (10) and (11)
Between K02 (female) (A) and (B)
40 Troubleshooting
Troubleshooting by failure code (Display of code)
(PC88MR-
120 ± 12 z
120 ± 12 z
Approx. 120
z
Approx. 60
z
Approx. 60
z
Approx. 60
z
Approx. 60
z
Approx. 120
z
40-281