Suzuki 2006 SX4, Service Manual

Page: 123 / 1478

Engine General Information and Diagnosis: 1A-79
6) Repeat Step 4).
7) Keep above vehicle speed for 8 min. or more. (Throttle valve opening is kept constant in this step.)
8) Repeat Step 5).
9) Check DTC and pending DTC.
DTC Troubleshooting
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”.
2 Is there DTC(s) other than fuel system (DTC P0171 / P0172)
and HO2S (DTC P0140)? Go to applicable DTC
diag. flow. Go to Step 3.
3 HO2S and its circuit check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Warm up engine to normal operating temperature and
keep it at 2000 r/min. for 60 sec.
3) Repeat racing engine (Repeat depressing accelerator
pedal 5 to 6 times continuously to enrich A/F mixture and
take foot off from pedal to enlean it).
Does HO2S output voltage indicate approx. 0 V for a few
seconds, then approx. 0.7 V?
Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”. Go to Step 4.
4 HO2S circuit check
1) Disconnect connector from HO2S and ECM with ignition
switch turned OFF.
2) Check for proper connection of each HO2S circuit
terminal to HO2S connector and to ECM connector.
3) If connections are OK, check HO2S circuit for the
following.
• Wiring harness resistance of each “Signal circuit of
HO2S” and “Ground circuit of HO2S” is less than 1
Ω
.
• Insulation resistance between “Signal circuit of HO2S”
and vehicle body ground is infinity.
• Insulation resistance of wire harness is infinity
between “Signal circuit of HO2S” terminal and each
other terminal at HO2S connector.
• Circuit voltage between “Signal circuit of HO2S” and
vehicle body ground is 0 V with ignition switch turned
ON.
Are they in good condition?
Go to Step 5. Repair or replace
defective wiring harness
/ connector.
5 HO2S heater circuit check
1) Check HO2S heater circuit referring to Step 2 to 4 of
“DTC P0037 / P0038: HO2S Heater Control Circuit Low /
High (Sensor-2, Bank-1)”.
Is circuit in good condition?
Go to Step 6. Repair or replace
defective wiring harness
/ connector.
6 Exhaust system check
1) Check exhaust system for exhaust gas leakage.
Is it OK?
Go to Step 7. Repair leakage of
exhaust system.
7 Fuel injectors and its circuit check
1) Check fuel injectors referring to “Fuel Injector Inspection
in Section 1G”.
Is check result satisfactory?
Go to Step 8. Faulty injection(s) or its
circuit.