Suzuki Liana RH418, Supplementary Service Manual

Page: 85 / 371

Engine General Information and Diagnosis: 1A-72
Troubleshooting
Inspection of ECM and Its Circuits
S3RH0B1104044
ECM and its circuits can be checked at ECM wiring couplers by measuring voltage, pulse signal and resistance.
CAUTION
!
ECM cannot be checked by itself. It is strictly prohibited to connect voltmeter or ohmmeter to ECM
with coupler disconnected from it.
Step Action Yes No
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2. Go to “Engine and
Emission Control
System Check” in this
section.
2 Check oil control valve circuit
1) Disconnect connectors from ECM with ignition switch
turned off.
2) Check for proper connection at G04-12 and G04-21
terminal of ECM connector.
3) If OK, measure resistance between G04-12 and G04-21
terminal of ECM connector.
Is resistance less than 10
Ω
?
Go to Step 3. Go to Step 5.
3 Check oil control valve circuit
Was resistance more than 6.5
Ω
in Step 2?
Go to Step 4. Go to Step 6.
4 Check oil control valve circuit for power short
1) Turn on ignition switch.
2) Measure voltage between G04-12 terminal of ECM
connector and vehicle body ground.
Is voltage less than 1 V?
Go to Step 6. “RED” or “GRN” wire is
shorted to power supply
circuit.
5 Check oil control valve circuit
1) Disconnect connector from oil control valve with ignition
switch turned off.
2) Measure resistance between G04-12 terminal of ECM
connector and “GRN” wire terminal of oil control valve
connector and between G04-21 terminal of ECM
connector and “BLK/YEL” wire terminal of oil control
valve connector.
Is each resistance less than 1
Ω
?
Go to Step 6. “GRN” wire or “BLK/
YEL” wire circuit is open
or high resistance.
6 Check oil control valve
Check oil control valve referring to “Oil Control Valve
Inspection in Section 1C”.
Is it in good condition?
Substitute a known
good ECM and recheck. Faulty oil control valve.