Suzuki AN400 Service Manual page 331

Heated oxygen sensor
(HO2S) [E-02,19]
C44
During O2 feedback control, O2 sensor voltage is higher than
the specification or lower than the specification.
No signal is detected during engine operation, or no electrical
power is supplied from battery.
HO2S lead wire/coupler connection.
Battery voltage supply to the HO2S.
SERVICING INFORMATION 9-3