Suzuki WagonR+ RB310 Service Manual page 1820

DTC P0136 HEATED OXYGEN SENSOR (HO2S) CIRCUIT MALFUNCTION
(SENSOR-2)
CIRCUIT DESCRIPTION
Main
fuse
"IG COIL"
DTC DETECTING CONDITION
DTC will set when A or B condition is detected.
A. Max. output voltage of HO2S-2 is lower than specified value or
Min. output voltage is higher than specified value while vehicle
driving.
B. Engine is warmed up and HO2S-2 voltage is 4.5 V or more.
(circuit open)
: 2 driving cycle detection logic, monitoring once/1 driving.
Ignition
switch
To HO2S-1 heater
GENERAL INFORMATION AND ENGINE DIAGNOSIS 6-1-57
Heater
POSSIBLE CAUSE
D Exhaust gas leakage
D "BLU" or "BRN/WHT" circuit open or
short
D Heated oxygen sensor-2 malfunction
D Fuel system malfunction