Kia 2004.5 Spectra Service Technical Training page 136

2004.5 Spectra Technology
The ignition timing is controlled by the ECM. Ignition
system diagnosis includes: checking primary and
secondary ignition components (i.e. spark plugs),
ignition cables, and coils through visual inspection;
and resistance, and scope checks. Measurement
specifications are on KSIS.
HO2S
All OBDII vehicles use oxygen sensors for two
purposes. Sensor 1 or front sensor provides a
feedback signal to the ECM for air-fuel ratio control.
Bank 2 or rear sensor is used to check catalytic
converter efficiency. Kia vehicles in current production
use conventional narrow range Zirconium (Zirconia)
Dioxide HO2S that generate a 0 to 1V signal in response
to the oxygen level measured in the exhaust stream.
Zirconium Dioxide HO2S is a Narrow Range Oxygen
Sensor that does not output a linear response to
changes in exhaust oxygen content. Rather, the
sensor's voltage output goes sharply higher than .5V
when the air-fuel mixture is considered rich and when
under .5V is considered lean. Thus every time the
voltage crosses over the mid-voltage (.5V), the signal
indicates to the PCM a switch from rich to lean or lean
to rich depending upon the O2 content in the exhaust.
Driveability
18