Suzuki Ignis Service Manual page 3307

6-106 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Step
5 Check HO2S–2 sensor ground.
1) With ignition switch turn ON, check voltage
between "ORN" wire terminal of HO2S–2
sensor connector and engine ground.
Is voltage about 0.1 V or less?
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 "BRN" wire
terminal of HO2S–2 sensor connector and
"C63-33" wire terminal of ECM connector.
Is resistance less than 5 Ω?
7 Check wire circuit.
1) Disconnect connectors from ECM with igni-
tion switch turned OFF.
2) Measure resistance between "BRN" wire
terminal of HO2S–2 sensor connector and
body ground.
Is resistance infinity?
8 Check HO2S–2 signal circuit.
1) Measure voltage between "BRN" wire termi-
nal of HO2S–2 sensor connector and vehi-
cle body ground.
Is voltage 0 V?
9 Check HO2S–2 heater circuit.
1) Check HO2S–2 heater circuit, referring to
"DTC P0037 HO2S Heater Control Circuit
Low (Sensor-2) DTC P0038 HO2S Heater
Control Circuit High (Sensor-2)".
Is circuit in good condition?
10 Check exhaust system.
1) Check exhaust system for exhaust gas
leakage.
Is it OK?
11 Check air intake system.
1) Check air intake system for clog or leak.
Is it OK?
Action Yes
Go to Step 6.
Go to Step 7.
Go to Step 8.
Go to Step 9.
Go to Step 10.
Go to Step 4 in DTC
P0171 and P0172 diagno-
sis flow table.
If it is in good condition,
go to Step 11.
Check HO2S–2 sensor,
referring to "Heated oxy-
gen sensor (HO2S-1 and
HO2S-2) heater on-vehicle
inspection" in Section 6E1.
If it is in good condition,
substitute a known-good
ECM and recheck.
No
"ORN" wire high resis-
tance circuit.
Poor "C63-28" terminal
connection.
Faulty ECM ground.
If they are OK, substitute
a known-good ECM and
recheck.
"WHT" wire high resis-
tance circuit or open cir-
cuit.
Poor "C63-33" terminal
connection.
Faulty ECM ground.
If they are OK, substitute
a known-good ECM and
recheck.
"BRN" wire shorted to
ground circuit.
"BRN" wire shorted to oth-
ers circuit.
Repair or replace it.
Repair exhaust system for
leakage.
Repair or replace.