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Diagnosis >Parameter<
As the ECU interprets fault reasons differently, it is often not enough only to read out the fault memory.
Fault codes are often not stored or the fault text delivers only insufficient comments on the defective
component.
Example 1:
Engine temperature can be within a range of -30°C to +120°C.
If the sensor r9.0°C, but real engine temperature is +80°C, then ECU will calculate a wrong injection
time. A fault code will not be set, as this temperature is logic for the ECU.
Example 2
Fault text: incorrect lambda probe signal
In both cases, a diagnosis is possible only, if the appropriate parameters are read out.
Mega macs 42 reads the parameters and displays them in plain text.
Maximum four parameters can be displayed also in diagrams.
A maximum of eight parameters can be called up but then only with figures and not with diagrams.
A task-oriented parameter selection facilitates the fault diagnosis.
Information about the parameters is stored.
Steps
1. Connect mega macs 42 as described in section E. Establish the communication.
macs 42 Section G 1/3
> parameter > engine
rpm
1/min
870
fuel pressure
bar
280
injection rate
mm_/H
11.7
accelerator position
%
35
f1 info f3 Channel
