| Test | TECH 1 | Notes | Nominal Values | Possible |
|---|---|---|---|---|
| Step | Display | Trouble | ||
| No. | Codes | |||
| 18 | O2 BLOCK LEARN 1 | Engine idling, | 44, 45 | |
| operating temperature | ||||
| C 20 NE, C 20 NEF, C 30 NE, C 30 LE: | 48 to 180 STEPS | |||
| 20 SE, 20 SER, 20 SEH, 20 NE : | 128 STEPS | - |
Note
Via the O2 BLOCK LEARN 1 learned deviations from the ideal mixture condition (e.g. by air leakage) are intercepted by the control unit and stored in the permanent memory.
The learning process takes place only if the oxygen regulation is active and the engine operating normally.
The O2 BLOCK LEARN 1 operates in the whole block learn range but dominates mainly in the lower engine speed range.
The correction values learned by the system are stored in a long term memory so that they are available also after the supply voltage has been switched off and the engine re-started.
With the O2 BLOCK LEARN 1 an evaluation of the learned values of the system can be made.
In order to be able to evaluate the deviation of the O2 BLOCK LEARN 1, O2 INTEGRATOR must be observed.
If this also lies outside the tolerance range, a statement can be made about the mixture condition of the engine.
Trouble-shooting: Nominal Value: Cause of Trouble:
With
· O2 BLOCK LEARN 1 < 48 STEPS 48 to 180 STEPS · See test step 17
and System becomes leaner, mixture too rich
O2 INTEGRATOR < 124 STEPS
· O2 BLOCK LEARN 1 > 180 STEPS 48 to 180 STEPS · See test step 17
and System becomes richer, mixture too lean
O2 INTEGRATOR > 132 STEPS