Suzuki GA413 Service Manual page 831

DTC P0135 HEATED OXYGEN SENSOR (HO2S) HEATER CIRCUIT
MALFUNCTION (SENSOR-1)
CIRCUIT DESCRIPTION
1. Heated oxygen sensor-1 (HO2S-1) heater
DTC DETECTING CONDITION
DTC will set when A or B condition is met.
A:
D Low voltage at terminal C23-6 when engine is
running at high load.
B:
D High voltage at terminal C23-6 when engine is
running under condition other than above.
: 2 driving cycle detection logic, Continuous
monitoring.
DTC CONFIRMATION PROCEDURE
WARNING:
D When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and be very careful during testing to avoid occurrence of an accident.
D Road test should be carried out with 2 persons, a driver and a tester.
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON, start engine and keep it at idle for 1 min.
3) Start vehicle and depress accelerator pedal fully for 5 sec. or longer.
4) Stop vehicle.
5) Check DTC in "DTC" mode and pending DTC in "PENDING DTC" mode.
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-55
POSSIBLE CAUSE
D HO2S-1 heater circuit open or shorted to ground
D ECM malfunction