|
Reading measured value block
Display Groups 008 to 099
Display Group 008 - Lambda learned values:
|
Read measured value block 08
|
⇒
|
◂ Indicated on display
|
|
2.0...5.0
ms
|
-10...+10
%
|
-8...+8
%
|
TB active
or
TB n. active
|
|
|
|
|
|
|
"TB active" (TB = fuel tank breather system) means that
solenoid valve 1 for activated charcoal filter is opening and
closing at intervals (i.e. is active) for a period of between 6 and 16 minutes.
"TB n. active" means that solenoid valve 1 for activated charcoal filter remains closed (i.e. is not active) for a period of 1 minute.
|
|
|
|
|
Lambda learned value at part throttle (multiplicative)
|
|
|
|
Lambda learned value when idling (additive)
|
|
|
Injection period
|
Test table, Display Group 008
|
|
|---|
|
Display zone
|
Readout on V.A.G 1551
|
Cause of fault
|
Fault remedy
|
|
1
|
|
- See Display Group 002, display zone 3
|
|
|
2
and
3
|
Low lambda learned
values
|
- Low lambda learned values for
- idling and normal lambda learned values for part throttle: oil may be diluted with petrol (high petrol
- content in oil)
|
- Disappears after motorway run or oil change
Display Group 007, display zone 2
=> Page 01-120
|
|
|
|
- Leak in injector
|
- Test injector
|
|
|
|
- Fuel pressure too high
|
- Check fuel pressure
=> Page 24-15
|
|
|
|
- Solenoid valve 1 for activated
- charcoal filter -N80 constantly open
|
- Test -N80 => Page 24-58
|
|
|
|
- Air mass meter -G70 defective
|
- Test -G70 => Page 24-33
|
|
|
|
- Lambda probe heating defective or lambda probe dirty
|
- Test lambda probe heating
=> Page 24-45
|
Note on display zones 2 and 3:
Low learned values mean that the engine is running too rich, and the lambda control compensates by leaning out the mixture.
Test table, Display Group 008
|
|
|---|
|
Display zone
|
Readout on V.A.G 1551
|
Cause of fault
|
Fault remedy
|
|
2
and
3
|
High lambda learned
values
|
- High lambda learned values for
- idling and lower lambda learned
- values for part throttle: unmetered air possible around intake manifold
|
- Rectify fault
Display Group 007, display zone 2
=> Page 01-120
|
|
|
|
- Injector blocked
|
- Check injection quantity
|
|
|
|
- Values in display zones 2 and 3 too high: air mass meter -G70 defective
|
- Test -G70
|
|
|
|
- Fuel pressure too low
|
- Check fuel pressure
|
|
|
|
- Unmetered air between -G70 and throttle valve
|
- Rectify fault
|
|
|
|
- Unmetered air at manifold gasket
|
|
|
|
|
- Lambda probe heating defective or lambda probe dirty
|
- Test lambda probe heating
|
Notes on display zones 2 and 3:
-
◆ High learned values mean that the engine is running too lean, and the lambda control compensates by enriching the mixture.
-
◆ If there is no voltage in the control unit, all the learned values will be set to zero.
Display Group 009 - Lambda learned values:
|
Read measured value block 9
|
⇒
|
◂ Indicated on display
|
|
760...880
rpm
|
-10...+10
%
|
0...1.0
V
|
-10...+10
%
|
|
|
|
|
|
|
Lambda learned value for idling (additive)
|
|
|
|
|
Lambda probe voltage
|
|
|
|
Lambda control
|
|
|
Engine speed shown in steps of 10 rpm
|
Display Group 010 - Fuel tank breather system:
|
Read measured value block 10
|
⇒
|
◂ Indicated on display
|
|
0....99
%
|
0.3...1.1
|
-5...+45
|
0.00...0.30
|
|
|
|
|
|
|
Purging rate of activated charcoal filter (ACF):
Readout "0.00" = nothing supplied from ACF system
Readout "0.30" = 30%of intake air mass supplied from ACF system
|
|
|
|
|
Fill level of activated charcoal filter system:
-3 means there is no petrol vapour in the activated charcoal filter system.
+32 means the activated charcoal filter system is full of petrol vapour.
|
|
|
|
Lambda correction factor for active fuel tank breather system
|
|
|
Duty cycle for solenoid valve 1 for activated charcoal filter (ACF)
|
Note on display zone 4:
The display shows the percentage of the overall intake volume which is supplied via the ACF system.
Display Group 011 - Fuel consumption:
|
Read measured value block 11
|
⇒
|
◂ Indicated on display
|
|
760...880
rpm
|
1.0...2.5
ms
|
0
km/h
|
0.5...1.5
ltr/h
|
|
|
|
|
|
|
Fuel consumption:
The specified value shown on the display relates only to idling without additional load from ancillaries (automatic gearbox, air conditioner, alternator, power steering pump).
|
|
|
|
|
Road speed
|
|
|
|
Engine load
|
|
|
Engine speed shown in steps of 40 rpm
|
Notes on display zone 2:
-
◆ The maximum engine load falls by around 10% for every 1000 m above sea level.
-
◆ The maximum engine load also falls by up to 10% at very high ambient temperatures.
-
◆ The values when driving at full throttle should be no less than the following:
- approx. 7.5 ms at 4000 rpm
- approx. 6.5 ms at 6000 rpm
Display Group 012 - Fuel consumption:
|
Read measured value block 12
|
⇒
|
◂ Indicated on display
|
|
760...880
rpm
|
10...14.5
V
|
0.5...1.5
ltr/h
|
6...12°
before TDC
|
|
|
|
|
|
|
Ignition timing - see Display Group 001, display zone 4
|
|
|
|
|
Fuel consumption - see Display Group 011, display zone 4
|
|
|
|
Battery voltage - see Display Group 003, display zone 2
|
|
|
Engine speed - see Display Group 001, display zone 1
|
Display Group 013 - Knock control:
|
Read measured value block 13
|
⇒
|
◂ Indicated on display
|
|
0..15°
crankshaft
|
0..15°
crankshaft
|
0..15°
crankshaft
|
0..15°
crankshaft
|
|
|
|
|
|
|
Ignition timing retardation by knock control, cylinder 4
|
|
|
|
|
Ignition timing retardation by knock control, cylinder 3
|
|
|
|
Ignition timing retardation by knock control, cylinder 2
|
|
|
Ignition timing retardation by knock control, cylinder 1
|
Notes on Display Group 013:
-
◆ The knock control operates at engine loads of 40% or more.
-
◆ At engine loads of more than 40% the display will show the current (instantaneous) ignition timing retardation values. At engine loads of less than 40% the display will show the last values used (constant readout).
-
◆ If there is audible knocking and no perceptible ignition timing retardation, increase the engine speed to above 3500 rpm for 5 seconds in order to activate the knock sensor fault recognition (diagnosis) function.
-
◆ If there is a significant difference between the ignition timing retardation value for one of the cylinders and the values for the other cylinders, the following faults are possible:
- Loose ancillaries
- Corrosion on plug connector
- Engine damage (e.g. oil burning because of defective piston)
Notes continued:
-
◆ If the ignition timing retardation values for all the cylinders are high, the following faults are possible:
- Corrosion on plug connector
- Wrong tightening torque (should be 20 Nm)
- Open circuit in wiring
- Knock sensor defective
- Loose ancillaries
- Poor-quality fuel (less than RON 95)
Display Group 014 - Knock control:
|
Read measured value block 14
|
⇒
|
◂ Indicated on display
|
|
760...880
rpm
|
1.0...2.5
ms
|
0..15°
crankshaft
|
0..15°
crankshaft
|
|
|
|
|
|
|
Ignition timing retardation by knock control, cylinder 2
|
|
|
|
|
Ignition timing retardation by knock control, cylinder 1
|
|
|
|
Engine load (injection period per revolution)
|
|
|
Engine speed shown in steps of 40 rpm
|
Note on Display Group 014:
With this display group it is possible to check the ignition timing retardation for cylinders 1 and 2 at certain engine speeds and under certain load conditions.
Display Group 015 - Knock control:
|
Read measured value block 15
|
⇒
|
◂ Indicated on display
|
|
760...880
rpm
|
1.0...2.5
ms
|
0..15°
crankshaft
|
0..15°
crankshaft
|
|
|
|
|
|
|
Ignition timing retardation by knock control, cylinder 4
|
|
|
|
|
Ignition timing retardation by knock control, cylinder 3
|
|
|
|
Engine load (injection period per revolution)
|
|
|
Engine speed shown in steps of 40 rpm
|
Notes on Display Group 015:
-
◆ With this display group it is possible to check the ignition timing retardation for cylinders 3 and 4 at certain engine speeds and under certain load conditions.
-
◆ Causes of ignition timing retardation: Display Group 013.
Display Group 016 - Knock control (idling):
|
Read measured value block 16
|
⇒
|
◂ Indicated on display
|
|
0.4...2.0
V
|
0.4...2.0
V
|
0.4...2.0
V
|
0.4...2.0
V
|
|
|
|
|
|
|
Knock sensor signal, cylinder 4
|
|
|
|
|
Knock sensor signal, cylinder 3
|
|
|
|
Knock sensor signal, cylinder 2
|
|
|
Knock sensor signal, cylinder 1
|
Notes on Display Group 016:
-
◆ If the difference between the highest and lowest knock control signals is more than 50%, this may be due to corrosion on the plug connector.
-
◆ If no faults are found as a result of the electrical test of the knock sensor (including wiring and connector), check the engine for loose ancillaries and mechanical damage. See Display Group 013.
-
◆ At higher engine speeds and engine loads the voltage signal displayed for the knock sensors can reach values of up to 5.1 volts.
Display Group 017 - Catalytic converter heating:
|
Read measured value block 17
|
⇒
|
◂ Indicated on display
|
|
760...880
rpm
|
1.0...2.5
ms
|
0...100
%
|
6...12°
before TDC
|
|
|
|
|
|
|
Ignition timing
|
|
|
|
|
Energy balance for catalyst heating
|
|
|
|
Engine load (injection period per revolution)
|
|
|
Engine speed shown in steps of 40 rpm
|
Notes on Display Group 017:
-
◆ To bring the catalyst up to operating temperature as quickly as possible after a cold start, the idling speed is increased and the ignition timing retarded. In the part throttle range only the ignition timing retardation remains activated.
-
◆ The rapid catalyst heating function is activated at starting temperatures of -9 to +39°C.
Notes continued:
-
◆ The function is aborted under the following conditions:
- Engine speed greater than 4000 rpm
- Engine load greater than 7.0 ms
- Fault registered in fault memory for air mass meter and coolant temperature sender
- Energy balance greater than 1.0
- Road speed greater than 55 km/h
- Altitude correction factor less than -20%(Display Group 018)
-
◆ When the function is aborted the display readout for the energy balance remains frozen and is reset to zero the next time the engine is started.
Display Group 018 - Altitude adaption:
|
Read measured value block 18
|
⇒
|
◂ Indicated on display
|
|
760...880
rpm
|
1.0...2.5
ms
|
0.5...3.0
ms
|
-50...+15
%
|
|
|
|
|
|
|
Altitude correction factor
|
|
|
|
|
Engine load from throttle valve angle
|
|
|
|
Engine load from air mass meter
|
|
|
Engine speed shown in steps of 40 rpm
|
Notes on Display Group 018:
-
◆ The engine control unit compares the load signal from the air mass meter with a load value calculated on the basis of the throttle valve angle and the engine speed. The difference between the two values is the altitude correction factor.
-
◆ At an altitude of approx. 400 m above sea level and under normal weather conditions, altitude adaption is not necessary.
- The correction factor at sea level is approx. 0%.
- At an altitude of 2000 m the correction factor is approx. -20%.
-
◆ The altitude adaption affects the following functions:
- Determining of injection quantity for starting
- Intake manifold pulsation compensation
Display Group 019 - Torque reduction (automatic gearbox)
|
Read measured value block 19
|
⇒
|
◂ Indicated on display
|
|
760...880
rpm
|
1.0...2.5
ms
|
1 0 1 1
|
6...12°
crankshaft
|
|
|
|
|
|
|
Ignition timing
|
|
|
|
|
Operating status:
1 X 1 X = no signal from pressure switch for power steering
0 X 1 X = signal from pressure switch for power steering
(steering wheel at full lock)
X 1 1 X = no gearshift signal
X 0 1 X = gearshift signal
X X 1 1 = no signal from clutch pedal switch (clutch not depressed)
X X 1 0 = signal from clutch pedal switch (clutch depressed)
|
|
|
|
Engine load
|
|
|
Engine speed shown in steps of 40 rpm
|
Notes on Display Group 019, display zone 3:
-
◆ This display group shows whether the engine control unit is receiving the gearshift signal from the gearbox control unit.
-
◆ Due to the very short signals the retardation of the ignition timing is not always recognised and therefore not displayed on V.A.G 1551/1552.
Notes continued:
-
◆ The power steering pressure switch is used to stabilise the idling speed when the steering wheel is at full lock (right or left).
-
◆ Testing power steering pressure switch -F88.
-
◆ The clutch pedal switch has the following functions:
- Smoothing out load change jolts
- Preventing excess engine revving when changing up to a higher gear
- Cruise control system (if fitted)
-
◆ Testing clutch pedal switch.
Display Group 020 - Operating conditions:
|
Read measured value block 20
|
⇒
|
◂ Indicated on display
|
|
760...880
rpm
|
Neutral
Gear engag
|
A/C-High
A/C-Low
|
Compr.ON
Compr.OFF
|
|
|
|
|
|
|
Air conditioner compressor ON/OFF
On vehicles with no air conditioner the display will always read "Compr.OFF".
|
|
|
|
|
Air conditioner
High = high hot/cold air output
Low = low hot/cold air output
On vehicles with no air conditioner the display will always read "AC-Low".
|
|
|
|
Selector lever in Neutral or with gear engaged
On vehicles with manual gearboxes the display will always read "Neutral".
|
|
|
Engine speed shown in steps of 10 rpm
|
Display Group 021 - Operating conditions for lambda control:
|
Read measured value block 21
|
⇒
|
◂ Indicated on display
|
|
760...880
rpm
|
1.0...2.5
ms
|
° C
|
λctrl.OFF
λctrl.ON
|
|
|
|
|
|
|
Lambda control OFF/ON
|
|
|
|
|
Coolant temperature
|
|
|
|
Engine load
|
|
|
Engine load shown in steps of 40 rpm
|
Notes on Display Group 021:
-
◆ The lambda control is activated by the engine control unit on the basis of the engine temperature, the engine temperature when starting and the intake air temperature.
-
◆ When the lambda control is switched off the engine runs according to the map stored in the control unit.
Display Group 023 - Adaption of throttle valve positioner:
|
Read measured value block 23
|
⇒
|
◂ Indicated on display
|
|
01000000
|
73...97 %
|
54...83 %
|
6...43 %
|
|
|
|
|
|
|
Max. stop of throttle valve positioner -V60
|
|
|
|
|
Emergency running stop of throttle valve positioner -V60
|
|
|
|
Min. stop of throttle valve positioner -V60
|
|
|
Learning requirement display
|
Note on display zone 1:
If the display does not show the specified value, perform adaption of throttle valve control part -J338 => Page 24-63.
Note on display zone 2, 3 and 4:
The display will show the stop values learned at the last basic setting.
Note on display zones 1, 2, 3 and 4:
If the display still does not show the specified value even after the basic setting has been performed, check the wiring for open circuits or short circuits and also check the plug connections for dirt or corrosion before fitting a new throttle valve control part.
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
X
|
Relevance of figures in 8-digit display
|
|
|
|
|
|
|
|
|
|
1 = (irrelevant)
|
|
|
|
|
|
|
|
|
|
2 = Min. stop learning process for throttle valve positioner sender -G127
0 = learning process completed; learning process OK
1 = learning process not completed; learning process not OK
|
|
|
|
|
|
|
|
|
|
3 = Max. stop learning process for throttle valve positioner sender -G127
0 = learning process completed; learning process OK
1 = learning process not completed; learning process not OK
|
|
|
|
|
|
|
|
|
|
4 = Min. stop learning process for throttle valve potentiometer -G69
0 = learning process completed; learning process OK
1 = learning process not completed; learning process not OK
|
|
|
|
|
|
|
|
|
|
5 = Max. stop learning process for throttle valve potentiometer -G69
0 = learning process completed; learning process OK
1 = learning process not completed; learning process not OK
|
|
|
|
|
|
|
|
|
|
6 = (irrelevant)
|
|
|
|
|
|
|
|
|
|
7 = Match throttle valve potentiometer -G69 with throttle valve positioner
sender -G127
0 = matching process needs to be carried out
1 = matching process complete; match achieved
|
|
|
|
|
|
|
|
|
|
8 = (irrelevant)
|
Display Group 024 - Knock control:
|
Read measured value block 24
|
⇒
|
◂ Indicated on display
|
|
760...880
rpm
|
1.0...2.5
ms
|
6...12°
before TDC
|
° cr/shaft
|
|
|
|
|
|
|
Total ignition timing retardation for cylinders 1 to 4
|
|
|
|
|
Ignition timing
|
|
|
|
Engine load
|
|
|
Engine speed shown in steps of 40 rpm
|
Notes on Display Group 024:
-
◆ The knock control must retard the ignition timing as soon as knocking is detected in order to prevent damage to the engine.
-
◆ Ignition timing retardation increases the exhaust temperature, which means there is a risk that the catalyst (catalytic converter) will overheat.
-
◆ Retarding the ignition timing in all the cylinders by, for example, 3°in relation to the crankshaft has exactly the same effect as retarding it by 12°in only one of the cylinders.
-
◆ To avoid overheating, a richer mixture is supplied when the total ignition timing retardation exceeds approx. 10°at full throttle. This has the effect of reducing the exhaust temperature.
Display Group 025 - Camshaft timing control:
|
Read measured value block 25
|
⇒
|
◂ Indicated on display
|
|
Idling
|
-30...+30
° cr/shaft
|
X X0
|
-3....+22
° cr/shaft
|
|
|
|
|
|
|
Camshaft position with camshaft timing control active
Camshaft in normal position: -3.0 ... 3.0°crankshaft angle
Camshaft in adjusted position: 15.0 ... 22.0°crankshaft angle
|
|
|
|
|
Operating state:
X X0 = camshaft timing control not active (late)
X X1 = camshaft timing control active
X 0X = intake manifold changeover function not active
X 1X = intake manifold changeover function active
(X = irrelevant)
|
|
|
|
Adjustment discrepancy with phase sender (Hall sender)
|
|
|
Operating state: idling, part throttle, full throttle, overrun, enrichment
|
Notes on Display Group 025:
See Display Group 026.
Display Group 026 - Camshaft timing control:
|
Read measured value block 26
|
⇒
|
◂ Indicated on display
|
|
760...880
rpm
|
1.0...2.5
ms
|
X X0
|
-3....+22
° cr/shaft
|
|
|
|
|
|
|
Camshaft position with camshaft timing control active
Camshaft in normal position: -3.0 ... 3.0°crankshaft angle
Camshaft in adjusted position: 15.0 ... 22.0°crankshaft angle
|
|
|
|
|
Operating state:
X X0 = camshaft timing control not active (late)
X X1 = camshaft timing control active
X 0X = intake manifold changeover function not active
X 1X = intake manifold changeover function active
(X = irrelevant)
|
|
|
|
Engine load
|
|
|
Engine speed
|
Note on display zone 4:
The adjustable camshaft has only two positions, i.e. the normal position (timing control not active) and the adjusted position (timing control active). If the camshaft timing control has been activated (see display zone 3), display zone 4 will show whether the camshaft position has in fact been adjusted (feedback signal).
Display Group 066 - Cruise control system, engine running at idling speed:
|
Read measured value block 66
|
⇒
|
◂ Indicated on display
|
|
km/h
|
X X X X
|
km/h
|
X X X X
|
|
|
|
|
|
|
Switch positions (driver-operated controls)
0000= cruise control switched on
0011= cruise control switched off (switch engaged)
0010= cruise control switches off before engagement point
0100= "SET" button pressed in
1000= "RES" ("resume") button pulled
|
|
|
|
|
Specified road speed. The display will show the last road speed that was set before the cruise control system was switched off (switch engaged in "OFF" position) or before the engine was switched off.
|
|
|
|
Brake and clutch switch positions; cruise control status (enabled or not enabled)
1000=cruise control enabled
1111=brake depressed (brake light switch)
1111=brake depressed (brake pedal switch)
1110=clutch depressed
|
|
|
Actual road speed
|
Note:
If the readouts are not as specified, test the cruise control system.
=> Electrical system; Repair group 96
Display Group 098 - Adaption of throttle valve control part:
|
Basic setting 98
|
⇒
|
◂ Indicated on display
|
|
0...5
V
|
0...5
V
|
Idling
Part throt
|
ADP. runs
ADP. O.K.
ADP ERROR
|
|
|
|
|
|
|
Adaption state
ADP. = adaption of throttle valve control part
|
|
|
|
|
Operating state
|
|
|
|
Voltage of potentiometer for idling speed positioner
|
|
|
Voltage of throttle valve potentiometer
|
Note on display zone 4:
ADP. = Adaption. Checking adaption of throttle valve control part (procedure for vehicles with cruise control).
Display Group 099 - Lambda control:
|
Read measured value block 99
|
⇒
|
◂ Indicated on display
|
|
760...880
rpm
|
°C
|
-10...+10
%
|
λ ctrl. OFF
λctrl. ON
|
|
|
|
|
|
|
Lambda control OFF/ON
Basic setting 04: λctrl. OFF
Read measured value block 08: λctrl. ON
|
|
|
|
|
Lambda control
|
|
|
|
Coolant temperature
|
|
|
Engine speed
|
Notes on Display Group 099:
-
◆ To assist fault-finding, the lambda mixture control function is deactivated when Display Group 099 is selected in "Basic setting" mode (function 04) and activated when it is selected in "Read measured value block" mode (function 08).
-
◆ The lambda mixture control function is automatically re-activated by exiting from function 04 "Basic setting".
-
◆ By pressing the keys 4 and 8 on the V.A.G 1551 it is possible to switch back and forth between function 04 "Basic setting" and function 08 "Read measured value block".
| 
