Suzuki SY413 Service Manual page 3293

6F2-4 IGNITION SYSTEM (J18 ENGINE)
DIAGNOSIS TABLE
Condition
Engine cranks, but will
not start or hard to start
Poor fuel economy or
engine performance
Oscilloscope waveforms
2V / Div
No.1 ignition trigger signal
2V / Div
Primary coil
current flow time
Waveforms at specified idle speed
Possible Cause
No spark
D Blown fuse for ignition coil
D Loose connection or disconnection of lead wire
D Faulty spark plug(s)
D Faulty ignition coil (in ignition coil assembly)
D Faulty CMP sensor
D Faulty ECM
D Maladjusted ignition timing
D Incorrect ignition timing
D Faulty spark plug(s)
D Faulty ignition coil (in ignition coil assembly)
D Faulty CMP sensor
D Faulty ECM
Reference
Oscilloscope waveforms of CMP sensor and No.1 ignition trigger
signal are as shown in figure when connecting oscilloscope be-
tween terminals C20-10 of ECM (PCM) connectors connected to
ECM (PCM) and ground, and between terminal E92-34 and
ground.
CMP sensor (REF signal)
10 ms / Div
Correction
Replace
Connect securely
Adjust, clean or replace
Replace
Replace
Replace
Adjust
Adjust
Adjust, clean or replace
Replace
Replace
Replace