Suzuki Wagon R Plus RB310, Service Manual

Page: 268 / 846

ENGINE GENERAL INFORMATION AND DIAGNOSIS (M13 ENGINE) 6-2-93
5 Check HO2S–1 sensor ground.
1) With ignition switch turned ON, check volt-
age between “BRN/WHT” wire terminal of
HO2S–1 sensor connector and engine
ground.
Is voltage about 0.1 V or less?
Go to Step 6. “BRN/WHT” wire high
resistance circuit.
Poor “E22-28” terminal
connection.
Faulty ECM ground.
If they are OK, substitute
a known-good ECM and
recheck.
6 Check wire circuit.
1) Disconnect connectors from ECM with igni-
tion switch turned OFF.
2) Remove ECM from vehicle body and con-
nect connectors to ECM.
3) Measure resistance between “RED” wire
terminal of HO2S–1 connector and “E22-
11” wire terminal of ECM connector.
Is resistance less than 5
Ω
?
Go to Step 7. “RED” wire high resis-
tance circuit or open cir-
cuit.
Poor “E22-11” terminal
connection.
Faulty ECM ground.
If they are OK, substitute
a known-good ECM and
recheck.
7 Check wire circuit.
1) Disconnect connector from ECM with igni-
tion switch turn OFF.
2) Measure resistance between “RED” wire
terminal of HO2S–1 sensor connector and
body ground.
Is resistance infinity?
Go to Step 8. “RED” wire shorted to
ground circuit.
8 Check HO2S–1 signal circuit.
1) Measure voltage between “RED” wire termi-
nal of HO2S–1 connector and vehicle body
ground.
Is voltage 0 V?
Go to Step 9. “RED” wire shorted to oth-
ers circuit.
9 Check HO2S–1 heater circuit.
1) Check HO2S–1 heater circuit, referring to
DTC P0031 and P0032 diagnosis flow table.
Is circuit in good condition?
Go to Step 10. Repair or replace it.
10 Check exhaust system.
1) Check exhaust system for exhaust gas leak-
age.
Is it OK?
Go to Step 4 in DTC
P0171 and P0172 diagno-
sis flow table.
If it is in good condition,
go to Step 11. Repair exhaust system for
leakage.
11 Check air intake system.
1) Check air intake system for clog or leak.
Is it OK?
Check HO2S–1 sensor,
referring to “Heated Oxy-
gen Sensor (HO2S–1 and
HO2S–2) Heater On-
Vehicle Inspection” in
Section 6E2.
If it in good condition, sub-
stitute a known-good
ECM and recheck. Repair or replace.
Step Action Yes No