Ignition System Troubleshooting; No Spark At Spark Plug - Honda CTX700N/ND Service Manual

IGNITION SYSTEM
TROUBLESHOOTING
•
Inspect the following before diagnosing the system
.
-
Faulty spark plug
- Loose spark plug cap or spark plug wire connection
-
Water got into the spark plug cap ( Leaking the ignition coil secondary voltage )
• If there is no spark at cylinder
,
temporarily exchange the ignition coil with a known
-
good one and perform the spark test
.
If there
is spark , the original ignition coil is faulty .
•
"
Initial voltage " of the ignition primary coil is the battery voltage with the ignition switch turned ON and engine stop switch
"
Q
"
( The engine is not cranked by the starter motor )
.
No spark at spark plug
Unusual condition Probable cause ( Check in numerical order )
Ignition coil
primary voltage
No initial voltage with the ignition
switch turned ON and engine
stop switch "
o
" ( Other electrical
components are normal )
.
1 . Faulty ignition switch
2
.
Faulty engine stop switch
3
.
Faulty fuel cut relay or its related circuits
4
.
An open circuit in Brown wire between the
ignition coil and fuel
cut relay
5 . Loose or poor connection of the primary terminal
, or an open
circuit in the primary coil
6
.
Faulty ECM / PCM ( in case when the initial voltage is normal with
the ECM/PCM connector disconnected ) .
Initial voltage is normal
,
but it
drops by 2
-
4 V while cranking
the engine
.
1
.
Incorrect peak voltage adaptor connectio
' ns (System is normal if
measured voltage is over the specifications with reverse
connections ) .
2 . Battery is undercharged ( Voltage drops largely when the engine
is started )
.
3
.
No voltage between the Black ( + ) wire and body ground (
-
) atthe
ECM / PCM connector or loosen ECM/
PCM connection
4 . An open circuit or loose
connection in Green
and Green/orange
wire at the ECM /PCM
5
.
An open circuit or loose connection in Blue / yellow or Yellow / blue
wire between the ignition coil and ECM/ PCM
6
.
Faulty sidestand switch , neutral diode ( CTX 700 / A / N / NA )
or
neutral switch
7 . Loose or poor connection or an open circuit in No . 6 related wires
-
Sidestand switch line : Green
/ white and Green
-
Neutral switch line ( CTX 700 / A / N / NA ) : Green / red and Light
green
-
Neutral switch line ( CTX 700 D / ND ) :
Light green
8
.
Faulty CKP sensor ( Measure peak voltage )
9
.
Faulty ECM / PCM ( in case when above No
. 1 through 8 are
normal ) .
Initial voltage is normal but there
is no peak voltage while cranking
the engine
.
1
.
Incorrect peak voltage adaptor connections
2 . Faulty peak voltage adaptor
3 . Faulty CKP sensor
4
.
Faulty ECM/ PCM ( in case when above No .
1 through 3 are
normal ) .
Initial voltage is normal but peak
voltage is lower than the
standard value
.
1 . The multimeter impedance is too low ; below 10 MQ /
DCV
.
2
. Cranking speed is
too slow ( Battery is undercharged ) .
3
. The sampling timing of the tester and measured pulse were not
synchronized ( System is normal if measured voltage is over the
standard voltage at least once ) .
4 . Faulty ECM/PCM ( in case when above No
.
1 through 3 are
normal ) .
Initial and peak voltages are
normal but no
spark jumps .
1
. Faulty spark plug
or leaking ignition coil secondary
current
ampere
2 . Faulty ignition coil
CKP sensor
Peak voltage is lower than
standard value .
1 . The multimeter impedance is too low ; below 10
MQ /DCV
.
2 . Cranking speed is too low
.
( Battery is undercharged . )
3
.
The sampling timing of the tester and measured pulse were not
synchronized ( System is normal if measured voltage
is over the
standard voltage at least once ) .
4
.
Faulty CKP sensor ( in case when above No . 1 through 3 are
normal ) .
No peak voltage 1
.
Faulty peak voltage adapter
2 . Faulty CKP sensor
5
-
5