Dacia Solenza 2004, Repair Manual

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IGNITION AND INJECTION
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The engines equipped with UCE injection type SIRIUS 32 are provided with oxygen sensors, as
follows:
- one upstream oxygen sensor – for engines corresponding to EURO 96 de-pollution norms.
- one upstream oxygen sensor and one downstream oxygen sensor – for engines corresponding
to EURO 2000 de-pollution norms.
OXYGEN SENSORS HEATING
Oxygen sensors heating control is given by UCE injection as follows:
- for upstream oxygen sensor – starting with engine starting.
- for downstream oxygen sensor – after a certain time from engine starting, imposed by the
UCE injection charts, being subject to engine RPM and water temperature, red only when the
acceleration pedal is not released.
UPSTREAM OXYGEN SENSOR VOLTAGE
After connecting the CLIP tester select “ Injection Diagnostic” and refer to “PR009 parameter:
Upstream oxygen sensor voltage”. The displayed value, expressed in mV, is representing the voltage
supplied towards UCE injection by the oxygen sensor placed upstream as the catalyst. When the
engine is running in the “closed loop” phase, voltage must fluctuate quickly between the following
limits:
- 20 mV ± 50 for poor fuel mixture;
- 840 mV ± 70 for rich fuel mixture.
Smaller is the difference between these two limits, less good the sensor information is
(generally this difference is of 500 mV).
DOWNSTREAM OXYGEN SENSOR VOLTAGE
After connecting the CLIP tester select “ Injection Diagnostic” and refer to “PR010 param-
eter: Downstream oxygen sensor voltage”. The displayed value, expressed in mV, is representing
the voltage supplied towards UCE injection by the oxygen sensor placed after the catalyst. This
sensor has the purpose to catalyst diagnostic and to perform a second checking, more exactly, of
the fuel mixture enriching. This function is becoming active only after a certain time of engine
running at warm and it is not active in the engine idling phase.
When the engine is running in “closed loop” phase and at stabilized speed, voltage must fluctuate
having between the maximal and minimal limits a difference of 600-mV ± 100. At deceleration,
voltage must be under 200 mV.
Enriching adjustment
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