|
Evaluating measured value blocks, display groups 10...29 -Ignition-
Evaluating measured value blocks, display groups 10...29 -Ignition-
|
Display group 10 -Ignition-
|
|
▪ Engine running at idling speed
|
|
Read measured value block 10
|
⇒
|
◂ Indicated on display
|
|
|
|
xxxx rpm
|
xxx %
|
x.x %
|
xx.x°BTDC
|
|
|
|
|
1
|
2
|
3
|
4
|
◂ Display zones
|
Specification
|
Evaluation
|
|
|
|
|
|
Ignition timing
|
5...15° BTDC
|
---
|
|
|
|
|
Throttle valve angle (potentiometer 1 -G187)
|
---
|
---
|
|
|
|
Engine load
|
10...25 %
|
|
|
|
Engine speed (idling speed):
|
760...880 rpm
|
=> Page 01-109
|
Evaluating display group 10, display zone 2 - Engine load
|
Appears on display
|
Possible fault cause
|
Fault elimination
|
|
Less than 10 %
|
- Lesser values can only occur when driving in overrun
|
|
|
More than 25 %
|
- Rough idling (not running on all cylinders)
|
- Injectors or spark plugs defective
|
|
|
- Electric consumers switched on
|
- Switch off electric consumers
|
|
|
- Steering wheel at full lock
|
- Set steering wheel to centre position
|
|
|
- Gear selected (automatic gearbox)
|
- Place selector lever in P or N
|
|
|
- Air mass meter defective
|
- Check air mass meter => Page 24-33
|
|
Display group 14 -Ignition- Misfire recognition
|
|
▪ Engine running at idling speed
|
|
Read measured value block 14
|
⇒
|
◂ Indicated on display
|
|
|
|
xxxx rpm
|
xxx %
|
xxx
|
Text
|
|
|
|
|
1
|
2
|
3
|
4
|
◂ Display zones
|
Specification
|
Evaluation
|
|
|
|
|
|
Misfire recognition (active, blocked)
|
activated
|
---
|
|
|
|
|
Total misfires
|
---
|
---
|
|
|
|
Engine load
|
10...25 %
|
=> Page 01-120
|
|
|
Engine speed (idling speed):
|
760...880 rpm
|
=> Page 01-109
|
|
Display group 22 -Ignition- Knock control
|
|
▪ Whilst driving
|
|
Read measured value block 22
|
⇒
|
◂ Indicated on display
|
|
|
|
xxxx rpm
|
x.xx %
|
xx.x °CA
|
xx.x °CA
|
|
|
|
|
1
|
2
|
3
|
4
|
◂ Display zones
|
Specification
|
Evaluation
|
|
|
|
|
|
No. 2 Cyl. retardation of ignition timing by knock control
|
0...12.75 °CA
|
=> Page 01-124
|
|
|
|
|
No. 1 Cyl. retardation of ignition timing by knock control
|
0...12.75 °CA
|
=> Page 01-124
|
|
|
|
Engine load
|
15...150 %
|
---
|
|
|
Engine speed
|
2 200...6 600 rpm
|
---
|
Note on display zones 3 and 4:
The displayed value should be 0.0 °CA at idling.
|
Display group 23 -Ignition- Knock control
|
|
▪ Whilst driving
|
|
Read measured value block 23
|
⇒
|
◂ Indicated on display
|
|
|
|
xxxx rpm
|
x.xx %
|
xx.x °CA
|
xx.x °CA
|
|
|
|
|
1
|
2
|
3
|
4
|
◂ Display zones
|
Specification
|
Evaluation
|
|
|
|
|
|
No. 4 Cyl. retardation of ignition timing by knock control
|
0...12.75 °CA
|
=> Page 01-124
|
|
|
|
|
No. 3 Cyl. retardation of ignition timing by knock control
|
0...12.75 °CA
|
=> Page 01-124
|
|
|
|
Engine load
|
15...150 %
|
---
|
|
|
Engine speed
|
2 200...6 600 rpm
|
---
|
Note on display zones 3 and 4:
The displayed value should be 0.0 °CA at idling.
Evaluating display groups 22/23, display zones 3 and 4 - Retardation of ignition
|
Appears on display
|
Possible fault cause
|
Fault elimination
|
|
All cylinders 12.75 °CA
|
- Knock sensor defective
|
- Check knock sensors => Page 28-14
|
|
|
- Connector corroded
|
|
|
|
- Knock sensor incorrectly tightened
|
- Loosen knock sensor and tighten to 20 Nm
|
|
|
- Ancillary components on engine loose
|
- Tighten ancillary components
|
|
|
- Poor fuel quality
|
- Change type of fuel
|
|
One cylinder deviates greatly from the others
|
- Connector corroded
|
- Check knock sensors => Page 28-14
|
|
|
- Engine damaged
|
- Check compression pressures:
|
|
|
- Ancillary components on engine loose
|
- Tighten ancillary components
|
|
Display group 28 -Ignition- Knock control diagnosis
|
|
▪ Whilst driving
|
|
Read measured value block 28
|
⇒
|
◂ Indicated on display
|
|
|
|
xxxx rpm
|
x.xx %
|
xx.x °C
|
Text
|
|
|
|
|
1
|
2
|
3
|
4
|
◂ Display zones
|
Specification
|
Evaluation
|
|
|
|
|
|
Result (Test On / OFF /
Syst. OK / n.OK)
|
Syst. OK
|
|
|
|
|
|
Coolant temperature
|
40...135 °C
|
=> Page 01-115
|
|
|
|
Engine load
|
50...150 %
|
---
|
|
|
Engine speed
|
2 200...6 600 rpm
|
---
|
| 
