Daewoo CIELO EURO III Manual page 324

1F – 155 ENGINE CONTROLS
Circuit Description
The engine control
module (ECM) continuously monitors the Oxygen Sen-
sor (O2S 1) activity for 100 seconds. During the monitor
period, the ECM counts the number of times that
the O2S 1 switches from rich to lean and from lean to
rich and adds the amount of time it took to complete all
switches. With this information, an average time for all
switches can be determined. If the average time to
switch is too slow, a DTC P0133 will set.
If the O2S 1 pigtail wiring, connector, or terminal is dam-
aged, the entire O2S 1 assembly must be replaced. Do
not attempt to repair the wiring, connector, or terminals.
In order for the sensor to function properly, it must have
a clean air reference provided to it. This clean air refer-
ence is obtained by way of the O2S 1 wire(s). Any at-
tempt to repair the wires, connector, or terminals could
result in the obstruction of the air reference and degrade
O2S 1 performance.
Conditions for Setting the DTC
Closed loop stoichiometry.
The engine run time is greater than 60 seconds
1.5L SOHC
The O2S 1 average transition time between 0.3–0.6
volts: lean to rich is greater than 175 milliseconds or
rich to lean is greater than 93 milliseconds.
The engine coolant temperature is greater than 70 C
(158 F).
The system voltage is greater than 10 volts.
The purge duty cycle (D.C) is less than 20%.
The rpm is between 1500 and 4000.
The airflow is between 9 and 40 g/sec.
DIAGNOSTIC TROUBLE CODE (DTC) P0133
OXYGEN SENSOR (O2S 1) SLOW RESPONSE
Engine running status within certain range (rpm,
TPS).
No related malfunctions (See P0131) and DTCs
P0131, P0132, P0134, P1171, P1167 are not set.
A 3 seconds delay after conditions met.
Action Taken When the DTC Sets
The Malfunction Indicator Lamp (MIL) will illuminate
after three (1.5L SOHC) or
consecutive trip with a fail.
The ECM will record operating conditions at the
time the diagnostic fails. This information will be
stored in the Freeze Frame and Failure Records buff-
ers.
A history DTC is stored.
Conditions for Clearing the MIL/DTC
The MIL will turn off after three (four –
1.5L SOHC) consecutive ignition cycles in which the
diagnostic runs without a fault.
TAA1F180
DAEWOO T-154 BL2,3