Testing is to be carried out with the HHT
The smooth running correction screen is located under actual values menu, check idle.
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CDI actual values
1 Start engine
2 Cold start
3 Warm-up
4 Check idle
5 Test engine
6 Driving mode
7 Drive authorization
8 CAN
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Smooth running correction - description
At idle the CDI control module carries out minor corrections in flow rate to each injector in order to achieve smooth running. Normally few corrections are necessary. The limit is + 4.5 ME.
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Maximum smooth running correction
If the maximum correction (+ 4,5 ME) is achieved in one or more cylinders, there could be a fault in the corresponding cylinder The test is carried out in the actuations menu, "Irregular running". In the process it is checked whether the rpm of the corresponding cylinder decreases.
Notes on HHT diagnosis common rail diesel injection (CDI) irregular running.
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HHT mask
Correct pattern
Shown on engine 611
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CDI actual values 3/3
09 Engine speed
750 rpm 751 1 rpm
10 Smooth-running correction
Cyl.1 -0.18 ME
Cyl.3 -0 01 ME
Cyl.4 -0.81 ME
Cyl.2 1.01 ME
Specified Stop
value <>
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HHT mask
Rejection pattern
Shown on engine 611
Fault on cylinder 2
CDI actual values 3/3
09 Engine speed
750 rpm 750 rpm
10 Smooth-running correction
Cyl.1 -0.35 ME
Cyl.3 -2.53 ME
Cyl.4 -1.66 ME
Cyl.2 4.50 ME
Specified Stop
value <>