Dtc P0171 Fuel System Too Lean (Bank-1); Dtc P0172 Fuel System Too Rich (Bank-1) - Suzuki 2000 Grand Vitara SQ625 Service Manual

6-1-84 ENGINE (H25 ENGINE)

DTC P0171 FUEL SYSTEM TOO LEAN (BANK-1)

DTC P0172 FUEL SYSTEM TOO RICH (BANK-1)

DTC DETECTING CONDITION AND TROUBLE AREA
DTC DETECTING CONDITION
P0171
Total fuel trim of BANK-1 is higher than 33 %.
P0172
Total fuel trim of BANK-1 is lower than –33 %.
DTC CONFIRMATION PROCEDURE
NOTE:
Check to make sure that following conditions are satisfied when using the DTC CONFIRMATION PROCE-
DURE.
WARNING:
D When performing a road test, select a place where there is no traffic or possibility of a traffic accident
and very careful during to avoid occurrence of an accident.
D Road test, should be carried out with 2 person, a driver and tester, on a level road.
D Intake air temperature: between –14_C and 70_C (6.8_F and 158_F)
D Atmospheric pressure: higher than 560 mmHg (Altitude: lower than 2790 m (9150 ft))
D Following DTCs are not detected: P0130, P0133 and P0134 (No.13)
(1) With ignition switch OFF, connect scan tool.
(2) Turn ON ignition switch and clear DTC by using scan tool if any.
(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 by using scan tool.
DTC TROUBLESHOOTING
STEP
1 Was "ENGINE DIAG. FLOW TABLE" performed?
2 Is there DTC(s) other than "P0171" and "P0172"?
3 Check intake system and exhaust system for leakage.
Are intake system and exhaust system in good
condition?
4 Check fuel pressure referring to "TABLE B-3" in this
section.
Is check result satisfactory?
5 Check fuel injectors (No.1, 3, 5) referring to "ENGINE
AND EMISSION CONTROL" section.
Is check result satisfactory?
ACTION
TROUBLE AREA
Vacuum leaks
Exhaust gas leakage
Fuel pressure out of specification
Fuel injector malfunction
Heated oxygen sensor malfunction
MAF sensor malfunction
ECT sensor malfunction
Fuel level sensor malfunction
YES
Go to Step 2.
Go to applicable
DTC FLOW TABLE.
Go to Step 4.
Go to Step 5.
Go to Step 6.
NO
Go to "ENGINE
DIAG. FLOW
TABLE".
Go to Step 3.
Repair or replace.
Repair or replace.
Faulty injector(s).