Suzuki Engine 2002 GRAND VITARA SQ625, Service Manual

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ENGINE GENERAL INFORMATION AND DIAGNOSIS (G16/J20 ENGINES) 6-77
TROUBLESHOOTING (DTC P0135)
Step Action Yes No
1 Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 HO2S-1 Heater Check :
1) Disconnect HO2S-1 coupler with ignition
switch OFF.
2) Check resistance between “GRY” wire ter-
minal and “BLK/WHT” wire terminal of
HO2S-1 coupler.
Resistance of HO2S-1 heater :
5 – 6.4
Ω
(at 20°C, 68°F)
Is it within above specification?
Go to Step 3. Replace HO2S-1.
3 HO2S-1 Heater Power Supply Check :
1) Connect HO2S coupler.
2) Check voltage between C51-2-4 terminal of
ECM (PCM) coupler and body ground with
ignition switch ON.
Is it 10 – 14 V?
Go to Step 4. “BLK/WHT”, or “GRY”
wire open, poor HO2S
coupler connection “GRY”
wire shorted to ground.
If wire and connections
are OK, substitute a
known-good ECM (PCM)
and recheck.
4 HO2S-1 Heater Operation Check :
1) Warm up engine, and check voltage
between C51-2-4 terminal of ECM (PCM)
coupler and body ground with engine idling.
Is it 0 – 1 V?
Intermittent trouble.
Check intermittent refer-
ring to “Intermittent and
Poor Connection” in Sec-
tion 0A. Poor C51-2-4 connection
of ECM (PCM) coupler.
If connection is OK, sub-
stitute a known-good
ECM (PCM) and recheck.