Ecm / Pcm - To-Combination Meter Two - Way Serial Communication; When There Is A Problem In The Serial Communication Line - Honda CTX700N/ND Service Manual

PGM - FI SYSTEM
ECM / PCM - to
-
COMBINATION METER TWO - WAY SERIAL COMMUNICATION
This motorcycle is equipped with a ECM/PCM
-
to
-
combination meter two
-
way serial communication system
.
The ECM / PCM sends the following information
to
combination meter :
-
High coolant temperature indicator signal
-
Engine oil pressure indicator signal
-
Engine speed signal
-
MIL signal
- Gear position indicator signal ( CTX 700 D / ND )
The combination meter sends the VS sensor signal and ignition switch OFF time information ( elapsed time after the ignition switch
is turned OFF ) to the ECM/PCM
.
The ECM/PCM uses this information and the VS sensor signal
to
detect an open circuit in the
EOP line
.
These signals are communicated between the combination
meter and ECM/PCM
via
one wire
.
This wire is
called the
serial
communication line
.
ECTSENSOR
—
EOP SWITCH
-
ECMor PCM
CKP SENSOR
—
CTX 700 D / ND only
TR SENSOR
SERIAL COMMUNICATION LINE
To COMBINATION METER :
-
High coolant temperature indicator signal
- Engine oil pressure indicator signal
-
Engine
speed
signal
- MIL signal
- Gear position indicator signal ( CTX 700 D / ND only )
To PCM :
-
VS sensor signal
-
Ignition switch OFF time information
COMBINATION
METER
•
C o
—
VS SENSOR
WHEN THERE IS A PROBLEM IN THE SERIAL COMMUNICATION LINE
When an open or short circuit occurs in the serial communication line , the
combination meter will indicate the problem in the following ways :
- The MIL [ 1 ] will come on .
-
The engine oil pressure indicator [ 2 ] will come on
.
-
The tachometer will go off .
-
The
high coolant temperature indicator will go off
.
-
Shift i n d i c a t o r [ 3 ] is blinking
.
( CTX 700 D / ND only )
When the ECM does not receive combination meter information , the ECM
will store DTC 86
-
1 . Check DTC 86
-
1 with the MCS ( page 4
-
8 )
.
Check the ECM in the ECM
communication
diagnostic mode ( page 4
- 30 ) .
Check the
combination meter with the combination meter communication
diagnostic mode ( page 22 - 8 )
.
[ 1 ]
2
XS
"
(
Lie
' S
n
u
[ 3 ]
1
4 fi