Suzuki 2000 Grand Vitara SQ416, Service Manual

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YH4
GRAND
VITARA
ENGINE (H25 ENGINE) 6-1-99
DTC DETECTING CONDITION AND TROUBLE AREA
DTC DETECTING CONDITION TROUBLE AREA
Output waveform of HO2S (S-2) becomes similar to that of
HO2S (S-1). TWC converter
Exhaust system
HO2S (SENSOR 2)
HO2S (SENSOR 2) circuit
ECM (PCM)
DTC CONFIRMATION PROCEDURE
NOTE:
Check to make sure that following conditions are satisfied when using this DTC CONFIRMATION PROCE-
DURE.
WARNING:
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.
Road test, should be carried out with 2 person, a driver and tester, on a level road.
Intake air temperature: between – 14 C and 70 C (6.8 F and 158 F)
Atmospheric pressure: higher than 560 mmHg (Altitude: lower than 2790 m (9150 ft))
Following DTCs are not detected: P0100 (No.33, 34), P0110 (No.23, 25), P0115 (No.14, 15), P0130, P0133,
P0134 (No.13), P0135, P0136, P0141, P0335, P0460, P0500 (No.24), P1450 and P1451
(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) Increase vehicle speed to 56 km / h (35 mph) or more.
(5) Keep above vehicle speed for 5 min. (Throttle valve operating is kept constant in this step.)
(6) Increase vehicle speed to 80 – 100 km / h (50 – 60 mph). (engine speed; 2500 – 3000 r / min.)
(7) Keep above vehicle speed for 1 min. (Throttle valve operating is kept constant in this step.)
(8) Stop vehicle and check DTC and pending DTC by using scan tool.
DTC TROUBLESHOOTING
STEP ACTION YES NO
1 Was “ENGINE DIAG. FLOW TABLE” performed? Go to Step 2. Go to “ENGINE
DIAG. FLOW
TABLE”.
2 Exhaust System Visual inspection:
(1) Check exhaust system for leaks, damage and loose.
Is it in good condition? Go to Step 3. Repair or replace.
3 HO2S BANK-1 (BANK-2) SENSOR-2 Circuit check:
(1) Check “R / B” and “Gr / Y” wire (“R / Y” and “Gr / Y” wire).
Are they in good condition? Go to Step 4. Repair or replace.
4 (1) Replace BANK-1 (BANK-2) HO2S SENSOR-2.
(2) Perform DTC confirmation procedure.
Is DTC P0420 (P0430) detected? Go to Step 5. Faulty BANK-1
(BANK-2) HO2S
SENSOR-2.
5 (1) Replace BANK-1 (BANK-2) warm up TWC converter.
(2) Perform DTC confirmation procedure.
Is DTC P0420 (P0430) detected? Substitute a known-
good ECM (PCM)
and recheck. Replace TWC
converter.