Dacia Solenza 2004, Repair Manual

Page: 116 / 891

IGNITION AND INJECTION
17
17 - 22
The purpose of the catalyst diagnostic is the detection of the disturbances leading to exceeding
an OBD step due to HC pollution emissions.
The catalyst storage capacity of the oxygen is the indicator of its condition. When the catalyst is
beginning to ”age”, the storage capacity of the oxygen is diminishing, in the same time with the
diminishing of the treatment capacity of the pollution gases.
IMPOSED CONDITIONS FOR DIAGNOSTIC STARTING
The catalyst diagnostic can be not performed but after a certain time of engine operation and
only if the preliminary conditions, when setting the contact on, are accomplished and preserved:
- no electric failure
- cylinder’s recognition performed
- no detected combustion misfire.
- non-performing of the catalyst diagnostic after contact setting on.
- correct performing of the “learnings” by the UCE injection.
- water temperature to be over 75°C
Catalyst diagnostic
Engine Speed Regime Manifold pressure Stabilization period Time before authorization
(Km/h) (rot/min) (mbar) (sec) (min)
E7J 63-130 1792-4000 430-739 11 17
FAILURES DETECTION
The diagnostic is to be performed on a stabilized range in the fifth gear, at the speed of 70 Km/h.
When the diagnostic starting conditions are accomplished, excitation peaks are applied, which is
leading to the oxygen bubbles sending to the catalyst. If the catalyst is good, it will absorb the
oxygen and the tension of the downstream oxygen sensor will remain at an average value. If the
catalyst is used, it will reject the oxygen and the oxygen sensor will wrongly define the phenom-
enon. The oxygen sensor tension will fluctuate. If the failures is three consecutively times con-
firmed, the OBD indicator would be on.
The test duration will be not exceeding 52 seconds.
ATTENTION: after performing this test, the contact setting on is imposed (key in M
position) before reading the results by means of the CLIP tester. Any contact setting off
before reading the test results, will lead to their wrong interpretation.
If after test performing, the CLIP tester is noticing the presence of the combustion mis-
fires, refer to the diagnostic method related to this symptom.
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