Suzuki 2000 Grand Vitara SQ625 Service Manual page 653

STEP
6 Ignition Coil Assembly Check
1) Substitute a known-good ignition coil assembly
and then repeat Step 2.
Is check result of Step 2 satisfactory?
7 CMP Sensor Check
1) Check CMP sensor.
Refer to Step 6 or 7 of DTC P0340 Diag.
Flow Table in SECTION 6 or 6-1.
Is check result satisfactory?
8 Ignition Timing Check
1) Check initial ignition timing and ignition timing
advance, referring to "Ignition Timing Check
And Adjustment" in this section.
Is check result satisfactory?
Oscilloscope waveforms
J20 Engine
CMP sensor
2V / Div.
1V / Div.
Primary coil
current flow
time
Waveforms at specified idle speed
H25 Engine
REF signal of
CMP sensor
2V / Div.
1V/Div.
Primary coil
current flow time
Waveforms at specified idle speed
ACTION
Reference
J20 engine
Oscilloscope waveforms of CMP sensor and No.1 ignition trigger
signal are as shown in figure when connecting oscilloscope be-
tween terminals C51-2-26 and C51-3-26 of ECM (PCM) connec-
tors connected to ECM (PCM), and between terminal C51-2-24 and
ground.
H25 engine
No.1 ignition
trigger signal
Oscilloscope waveforms of CMP sensor REF signal and No.1 igni-
tion trigger signal are as shown in figure when connecting oscillo-
5ms / Div.
scope between terminal C51-3-10 of ECM (PCM) connector con-
nected to ECM (PCM) and ground, and between terminal C51-2-13
and ground.
No.1 ignition
trigger signal
10ms / Div.
IGNITION SYSTEM (FOR J20 / H25 ENGINES) 6F2-5
YES
Malfunction of igni-
tion coil assembly.
Substitute a known-
good ECM (or PCM)
and then repeat Step
2.
System is in good
condition.
NO
Go to Step 7.
Tighten CMP sensor
bolt or replace CMP
sensor.
Adjust ignition timing
or check ECM (PCM)
input signals related
to this system.