Daewoo CIELO EURO III Manual page 336

1F – 167 ENGINE CONTROLS
OXYGEN SENSOR (O2S 1) TRANSITION RATIO
Circuit Description
The engine control
module (ECM) monitors the Oxygen Sensor (O2S 1) ac-
tivity for 60 seconds after closed loop and stoichiometric
operation have been established. During the monitoring
period the ECM counts the number of times that
the O2S 1 responds from rich-to-lean and adds the
amount of time it took to complete all transitions. With
this information, an average time for all transitions can
be determined. The ECM then divides the rich-to-
lean average by the lean-to-rich average to obtain a ra-
tio. If the O2S 1 transition time ratio is not within this
range, DTC P1134 will be set, indicating that the O2S 1
is not responding as expected to changes in exhaust ox-
ygen content.
Conditions for Setting the DTC
Closed loop stoichiometry.
The engine run time is greater than 60 seconds.
1.5L SOHC
O2S 1 transition ratio lean-to-rich to rich-to lean is out
of range (0.4395, 3.8).
Engine coolant temperature is greater than 70 C
(158 F).
The purge duty cycle (D.C.) is less than 20%.
Engine speed is between 1500 and 3000 rpm.
The airflow is between 9 and 30 g/sec.
Engine running status within certain range (rpm,
TPS).
No related malfunctions (See P0131) and DTCs
P0131, P0132, P0134, P1167, P1171 are not set.
3 second delay after conditions met.
DIAGNOSTIC TROUBLE CODE (DTC) P1134
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 store conditions which were pres-
ent when the DTC was set as Freeze Frame and in
the Failure Records data.
A history DTC is stored.
Conditions for Clearing the MIL/DTC
The ECM will turn the MIL OFF on the third
(fourth – 1.5L SOHC) consecutive trip
cycle during which the diagnostic has been run and
the fault condition is no longer present.
A history DTC will clear after 40 consecutive warm-up
cycles have occurred without a fault.
DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
A malfunction in the O2S 1 ignition feed or ground circuit
may cause a DTC P1134 to set. Check O2S 1 circuitry
for intermittent faults or poor connections. If connections
TAA1F180
DAEWOO T-154 BL2,3