Suzuki Wagon R Plus RB310, Service Manual

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6-2-106 ENGINE GENERAL INFORMATION AND DIAGNOSIS (M13 ENGINE)
DTC P0171 System Too Lean
DTC P0172 System Too Rich
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
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) Operate vehicle within freeze frame data condition as noted for 5 min.
5) Stop vehicle and check DTC and pending DTC.
8 Check HO2S–2 heater power circuit.
1) Disconnect connectors from ECM with igni-
tion switch turned OFF.
2) Connect connector to HO2S–2 with ignition
switch turned OFF.
3) Measure resistance between “E23-3” and
“E21-28” wire terminals of ECM connector.
Is resistance below 30
Ω
?
HO2S–2 heater circuit are
OK.
Substitute a known-good
ECM and recheck. “BLU/RED” wire high
resistance circuit.
Step Action Yes No
DTC Detecting Condition Trouble Area
P0171:
Total fuel trim is higher than 35%.
P0172:
Total fuel trim is lower than –35%.
(2 driving cycle detection logic) • Vacuum leaks
• Exhaust gas leakage
• Fuel pressure out of specification
• Fuel injector malfunction
• Heated oxygen sensor–1 malfunction
• MAF sensor malfunction
• ECT sensor malfunction
WARNING:
• When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and very careful during testing to avoid occurrence of an accident.
• Road test should be carried out with 2 person, a driver and tester, on a level road.
NOTE:
Check to make sure that the following conditions are satisfied when using this DTC CONFIRMATION
PROCEDURE.
• Intake air temp.: –7°C (19.4°F) or higher
• Altitude (barometric pressure): 2500 m, 8200 ft or less (540 mmHg, 72 kPa or more)