Suzuki Engine 2002 GRAND VITARA SQ420 Service Manual page 82

TROUBLESHOOTING (DTC P0135)
Step
1 Was "Engine Diag. Flow Table" performed?
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 :
Ω
5 – 6.4 (at 20°C, 68°F)
Is it within above specification?
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?
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?
ENGINE GENERAL INFORMATION AND DIAGNOSIS (G16/J20 ENGINES) 6-77
Action Yes
Go to Step 2.
Go to Step 3.
Go to Step 4.
Intermittent trouble.
Check intermittent refer-
ring to "Intermittent and
Poor Connection" in Sec-
tion 0A.
No
Go to "Engine Diag. Flow
Table".
Replace HO2S-1.
"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.
Poor C51-2-4 connection
of ECM (PCM) coupler.
If connection is OK, sub-
stitute a known-good
ECM (PCM) and recheck.