DTC Confirmation Procedure
• When performing a road test, select a place where there is no traffic or possibility of a traffic
accident and be very careful during testing to avoid occurrence of an accident.
• Road test should be carried out by 2 persons, a driver and a tester, on a level road.
Check to make sure that following conditions are satisfied when using this "DTC Confirmation
• Intake air temperature at engine start: –10 °C (14 °F) to 80 °C (176 °F)
• Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
• Engine Coolant temperature: 70 °C (158 °F) or more
• Altitude (barometric pressure): 2500 m, 8200 ft or less (560 mmHg, 74.4 kPa or more)
1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Increase vehicle speed to 60 – 80 km/h (37 – 50 mile/h) at 5th gear or D range.
5) Release accelerator pedal and with engine brake applied, keep vehicle coasting (with fuel cut for 4 sec. or more),
then stop vehicle and run engine at idle speed for 60 sec. or more.
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.
Before this troubleshooting is performed, read the precautions for DTC troubleshooting referring to
"Precautions for DTC Troubleshooting".
Was "Engine and Emission Control System Check"
Is there DTC(s) other than fuel system (DTC P0171 / P0172)
and HO2S-2 (DTC P0140)?
HO2S-2 and its circuit check
1) Connect scan tool to DLC with ignition switch turned
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-2 output voltage indicate deflection between
over 0.35 V and below 0.25 V?
Engine General Information and Diagnosis:
Go to Step 2.
Go to applicable DTC
Go to "DTC P0171 /
P0172: Fuel System
Too Lean / Rich".
Go to "Engine and
Go to Step 3.
Go to Step 4.