Suzuki Wagon R Manual page 1152

6-1-60 GENERAL INFORMATION AND ENGINE DIAGNOSIS
DTC P0141 HEATED OXYGEN SENSOR (HO2S) HEATER CIRCUIT
MALFUNCTION (SENSOR-2)
CIRCUIT DESCRIPTION
Main
fuse
"IG COIL"
DTC DETECTING CONDITION
DTC will set when A or B condition it met.
A. Low voltage at terminal E21-19 for specified time after engine
start or while engine running at high load.
B. High voltage at terminal E21-19 while engine running under
other than above condition.
: 2 driving cycle detection logic, continuous monitoring.
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF once and then ON.
2) Clear DTC, start engine and warm up engine to normal operating temperature.
3) Keep it at 2000 r/min for 2 min.
4) Check pending DTC in "ON BOARD TEST" or "PENDING DTC" mode and DTC in "DTC" mode.
Ignition
switch
To HO2S-1 heater
Heater
POSSIBLE CAUSE
D HO2S-2 heater circuit open or shorted
to ground
D ECM (PCM) malfunction