|
Self-diagnosis for the Motronic system
Reading measured value block: Display Groups 08 to 99
Display Group 08: Lambda learned values (warm engine, coolant temperature not less than +85 °C)
|
Read measured value block 08
|
⇒
|
◂ Display readout
|
|
1...3
ms
|
-10...+10
%
|
-8...+8
%
|
TB active
or
TB not active
|
|
|
|
|
|
|
"TB active" means that the solenoid valve 1 for the activated charcoal container is pulsing (6 to 16 minutes)
"TB not active" means that solenoid valve 1 for activated charcoal filter is constantly closed (1 minute).
|
|
|
|
|
Lambda learned value at part load (multiplicative)
multiplicative means that the fault occurs throughout the entire speed range and load range.
|
|
|
|
Lambda learned value at part load (additive)
additive means that the fault only occurs during idling
|
|
|
Injection period
▪ 1...3 ms: OK
▪ less than 1 ms: High proportion from tank breather system
▪ greater than 3 ms: Engine loaded => Switch off consumers
|
Test table, Display Group 08
|
|
|---|
|
Display zone
|
Readout on V.A.G 1551
|
Cause of fault
|
Fault remedy
|
|
2
and
3
|
low lambda learned values
|
- Low lambda idling learned values with normal lambda -part-load-learned values: oil may be diluted with petrol (high petrol content in oil)
|
- Disappears after drive on motorway or oil change
Display Group 07, display zone 2
=> Page 01-91
|
|
|
|
- Injector leaking
|
- Check the injector=> Page 24-23
|
|
|
|
- Fuel pressure too high
|
- Check fuel pressure
|
|
|
|
- -N80 solenoid valve 1 for activated charcoal canister is constantly open
|
- Check -N80 prüfen => Page 24-57
|
|
|
|
- -G70 air mass meter defective
|
- Check -G70 => Page 24-31
|
|
|
|
- Lambda probe heating defective or lambda probe dirty
|
- Check lambda probe heating
|
Note on display zones 2 and 3:
Low values mean that the engine is running too rich, and the lambda control is compensating by leaning out the mixture.
Test table, Display Group 08
|
|
|---|
|
Display zone
|
Readout on V.A.G 1551
|
Cause of fault
|
Fault remedy
|
|
2
and
3
|
high lambda
learned values
|
- High lambda - idling- learned values with lower lambda -part-load-learned values: possibility of unmetered air around intake manifold
|
- Eliminate faults
Display Group 07, display zone 2
=> Page 01-91
|
|
|
|
- Injector blocked
|
- Check injection quantity
|
|
|
|
- Display zones 2 and 3 high: -G70 air mass meter defective
|
- Check -G70 => Page 24-31
|
|
|
|
- Fuel pressure too low
|
- Check fuel pressure
|
|
|
|
- Unmetered air between -G70 air mass meter and throttle valve
|
- Rectify fault
|
|
|
|
- Unmetered air at manifold gasket
|
|
|
|
|
- Lambda probe heating defective or lambda probe dirty
|
- Check lambda probe heating
|
Notes on display zones 2 and 3:
-
◆ High learned values mean that the engine is running too lean, and therefore the lambda control is compensating by enriching the mixture.
-
◆ If there is no voltage in the control unit, all the learned values will be reset.
Display Group 09: Lambda learned values (warm engine, coolant temperature not less than +85 °C)
|
Read measured value block 9
|
⇒
|
◂ Display readout
|
|
rpm
|
-10...+10
%
|
0...1.0
V
|
-10...+10
%
|
|
|
|
|
|
|
Lambda learned value when idling
▪ -10...+10 %: OK
▪ Outside tolerance: Check lambda control => Page 24-44
|
|
|
|
|
Lamba probe voltage
▪ Voltage constantly fluctuates between - 0.1...+0.3 V and 0.7...1.0 V: OK
▪ -0.1...+0.3 V: Large amount of residual oxygen, mixture too lean
▪ 0.7...1.0 V: Small amount of residual oxygen, mixture too rich
▪ constant 0.45...0.50 V: Lambda probe not functioning
▪ => Check lambda control - Page 24-44
|
|
|
|
Lambda control
▪ -10...+10 %: OK
▪ Outside tolerance: Check lambda control => Page 24-44
|
|
|
Engine speed is shown in increments of 10
|
Display Group 10, Fuel tank breather (warm engine, coolant temperature not less than +85°C)
|
Read measured value block 10
|
⇒
|
◂ Display readout
|
|
0...99
%
|
0.3...1.25
|
-3...+32
%
|
0.00...0.30
|
|
|
|
|
|
|
Activated charcoal filter purging quantity (ACF)
▪ At value "0.00", nothing is supplied from the ACF system
▪ At value "0.30", 30% of the intake air mass supplied is supplied by the ACF system
|
|
|
|
|
Fill level of activated charcoal filter canister
▪ At -3 % there is no petrol vapour in the activated charcoal canister.
▪ At +32 % the activated charcoal canister is full of petrol vapours.
|
|
|
|
Lambda correction factor with active fuel tank breather system
▪ less than 1.00 Tank breather supplying rich mixture, lambda control reduces the quantity injected
▪ 1.00: No fuel tank breather function or fuel tank breather supplying ideal mixture (λ= 1)
▪ Greater than 1.00 Tank breather supplying lean mixture, lambda control increases the quantity injected
|
|
|
Signal ratio for -N80 solenoid valve 1 for activated carbon canister (ACF)
▪ Signal ratio 0 % means that the -N80 is closed
▪ Signal ratio 99 % means -N80 is fully open
|
Display Group 11 - Fuel consumption:
|
Read measured value block 11
|
⇒
|
◂ Display readout
|
|
800...920
rpm
|
0.5...1.5
ms
|
0
km/h
|
0.5...1.5
ltr/h
|
|
|
|
|
|
|
Fuel consumption:
The specified value shown on the display only relates to idling without any additional load from ancillaries (automatic gearbox, air conditioner, alternator, power steering pump).
|
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|
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|
Driving speed
|
|
|
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Engine load
|
|
|
Idling speed is shown in increments of 40
|
Notes on display zone 2:
-
◆ The maximum engine load decreases by about 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 load should not be less than the following:
- approx. 7.5 ms at 4000 rpm
- approx. 6.5 ms at 6000 rpm
Display Group 12 - Fuel consumption:
|
Read measured value block 12
|
⇒
|
◂ Display readout
|
|
800...920
rpm
|
10...14.5
V
|
0.5...1.5
ltr/h
|
3...12°
BTDC
|
|
|
|
|
|
|
Ignition timing
▪ 3...12.0°BTDC OK
▪ greater than 12.0°BTDC: Engine loaded => Switch off consumers
|
|
|
|
|
Fuel consumption:
The specified value shown on the display relates only to idling without any additional load from ancillaries (automatic gearbox, air conditioner, alternator, power steering pump).
|
|
|
|
Battery voltage
▪ 10.000...14.500 V: OK
▪ Outside tolerance: Check supply voltage from engine control unit => Page 28-19
|
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|
Engine speed
|
Display Group 13 - Knock control:
|
Read measured value block 13
|
⇒
|
◂ Display readout
|
|
0...15°
crankshaft
|
0...15°
crankshaft
|
0...15°
crankshaft
|
0...15°
crankshaft
|
|
|
|
|
|
|
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 ignition timing retardation by knock control
|
Notes on Display Group 13:
-
◆ The knock control is active from an engine load of greater than 40 %.
-
◆ At engine loads of more than 40 %, the display will show the current ignition timing retardation values. At engine loads of less than 40 % the display will constantly show the last values used.
-
◆ 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 the connector
- Engine damage (e.g. oil combustion because of defective piston)
Notes on Display Group 13:
-
◆ If the ignition timing retardation values for all the cylinders are high, the following faults are possible:
- Corrosion on plug the connector
- Tightening torque (20 Nm) not OK
- Open circuit
- Knock sensor defective
- Loose ancillaries
- Poor quality fuel (less than RON 95)
Display Group 14 - Knock control:
|
Read measured value block 14
|
⇒
|
◂ Display readout
|
|
rpm
|
ms
|
0...15°
crankshaft
|
0...15°
crankshaft
|
|
|
|
|
|
|
Cylinder 2 ignition timing retardation by knock control
|
|
|
|
|
Cylinder 1 ignition timing retardation by knock control
|
|
|
|
Engine load (injection period per revolution)
|
|
|
Idling speed is shown in increments of 40
|
Note on Display Group 14:
With this display group it is possible to check the ignition timing retardation for cylinders 1 and 2 at specific engine speeds and under specific load conditions.
Display Group 15 - Knock control:
|
Read measured value block 15
|
⇒
|
◂ Display readout
|
|
rpm
|
ms
|
0...15°
crankshaft
|
0...15°
crankshaft
|
|
|
|
|
|
|
Cylinder 4 ignition timing retardation by knock control
|
|
|
|
|
Cylinder 3 ignition timing retardation cylinder by knock control
|
|
|
|
Engine load (injection period per revolution)
|
|
|
Idling speed is shown in increments of 40
|
Notes on Display Group 15:
-
◆ With this display group it is possible to check the ignition timing retardation for cylinders 3 and 4 at specific engine speeds and under specific load conditions.
-
◆ Causes of ignition timing retardation: Display Group 13 .
Display Group 16 - Knock control: (Idling):
|
Read measured value block 16
|
⇒
|
◂ Display readout
|
|
400...1400
mV
|
400...1400
mV
|
400...1400
mV
|
400...1400
mV
|
|
|
|
|
|
|
Knock sensor signal, cylinder 4
|
|
|
|
|
Knock sensor signal, cylinder 3
|
|
|
|
Knock sensor signal, cylinder 2
|
|
|
Knock sensor signal, cylinder 1
|
Notes:
-
◆ 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 check on the knock sensor, the wiring and the plug connector, check the engine for loose ancillaries or mechanical damage. Display Group 13 .
-
◆ At higher engine speeds and engine loads, the voltage signal displayed for the knock sensors may reach values of up to 5.1 volts.
Display Group 17 - Catalyst heating:
|
Read measured value block 17
|
⇒
|
◂ Display readout
|
|
...
rpm
|
...
ms
|
...
%
|
...°
BTDC
|
|
|
|
|
|
|
Ignition timing
|
|
|
|
|
Energy balance for catalyst heating
|
|
|
|
Engine load (injection period per revolution)
|
|
|
Idling speed is shown in increments of 40
|
Notes on Display Group 17:
-
◆ To bring the catalyst up to operating temperature as quickly as possible after a cold start, increase the idling speed and retard the ignition timing. In the part load range, only the ignition timing retardation remains activated.
-
◆ The rapid catalyst heating function is activated at starting temperatures of from -9 to +39 °C.
-
◆ The function is terminated under the following conditions:
- Engine speed greater than 4000 rpm
- Engine load greater than 7.0 ms
- Fault in fault memory for air mass meter and sensor for coolant temperature
- Speed greater than 55 km/h
- Altitude correction factor less than -20 % (Display Group 18)
-
◆ When the function is terminated, the display readout for the energy balance remains frozen and is reset the next time the engine is started.
Display Group 18 - Altitude adaptation:
|
Read measured value block 18
|
⇒
|
◂ Display readout
|
|
....
rpm
|
...
ms
|
...
ms
|
-50...+10
%
|
|
|
|
|
|
|
Altitude correction factor
▪ Outside the display limits, check the altitude sensor => Page 24-40
|
|
|
|
|
Engine load from throttle angle after altitude correction
▪ No specified value
|
|
|
|
Engine load from air mass meter
|
|
|
Idling speed is shown in increments of 40
|
Notes on Display Group 18:
-
◆ The engine control unit compares the load signal from the air mass meter with a load value calculated from the throttle 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 adaptation 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 adaptation affects the following functions:
- Determination of starting fuel delivery
- Intake manifold-pulsation compensation
Display Group 19 up to model year 1998 - Torque reduction (automatic gearbox)
|
Read measured value block 19
|
⇒
|
◂ Display readout
|
|
760...880
rpm
|
1.0...2.5
ms
|
1 0 1 1
|
6...12°
BTDC
|
|
|
|
|
|
|
Ignition timing
|
|
|
|
|
Operating status
▪ X 1 X = no gearbox intervention signal
▪ X 0 X = gearbox intervention signal
▪ X = (display has no meaning)
|
|
|
|
Engine load
|
|
|
Idling speed is shown in increments of 40
|
Notes on Display Group 19:
-
◆ This Display Group may be used to evaluate whether the engine control unit is receiving the gearbox intervention signal from the gearbox control unit.
-
◆ Because of the brief signal, the V.A.G 1551 does not always recognise the ignition timing retardation.
Display Group 19 from model year 1998, Gearshift signals
|
Read measured value block 19
|
⇒
|
◂ Display readout
|
|
760...880
rpm
|
1.0...2.5
ms
|
1 0 1 1
|
6...12°
BTDC
|
|
|
|
|
|
|
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 on full lock)
X 1 1 X = no gearbox intervention signal
X 0 1 X = no gearbox intervention signal
X X 1 1 = No signal from clutch pedal switch (clutch not depressed)
X X 1 0 = Signal from clutch pedal switch (clutch not depressed)
|
|
|
|
Engine load
|
|
|
Idling speed is shown in increments of 40
|
Notes on Display Group 19:
-
◆ The function of the power steering pressure switch is to stabilise the idling speed when the steering wheel is on full lock (left or right).
-
◆ Check F88 power steering pressure switch .
-
◆ Check gearbox intervention signal .
-
◆ The clutch pedal switch is used to
- suppress the load change jolt
- prevent engine-speed overshoots on changing up
- Cruise control system (if there is one)
-
◆ Check clutch pedal switch .
Display Group 20 - Operating status:
|
Read measured value block 20
|
⇒
|
◂ Display readout
|
|
...
rpm
|
Neutral
Driving position ON
|
A/C - high
A/C - low
|
Compr.ON
Compr.OFF
|
|
|
|
|
|
|
Air conditioner compressor
▪ Compr. ON or compr. OFF: OK
▪ For vehicles with no air conditioner, "Compr. .OFF" is always displayed.
|
|
|
|
|
Air conditioner
▪ A/C high = high heating or cooling power
▪ A/C low = low heating or cooling power
▪ For vehicles with no air conditioner, "A/C - LOW" is always displayed
|
|
|
|
Selector lever position
▪ Neutral or. driving position ENGAGED OK
▪ For cars with manual gearboxes, the display will always show "Driving position engaged".
|
|
|
Engine speed is shown in increments of 10
|
Display Group 21 - Operating status for lambda control:
|
Read measured value block 21
|
⇒
|
◂ Display readout
|
|
...
rpm
|
...
ms
|
...
°C
|
λ-control OFF
λ-control ON
|
|
|
|
|
|
|
Lambda control
▪ λ-control OFF = lambda control off
▪ λ-control ON = lambda control on
|
|
|
|
|
Coolant temperature
|
|
|
|
Engine load
|
|
|
Idling speed is shown in increments of 40
|
Notes on Display Group 21:
-
◆ The lambda control is activated by the engine control unit in response to the engine temperature, the engine temperature on 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 23 -(Adaptation of the throttle valve positioner):
|
Read measured value block 23
|
⇒
|
◂ Display readout
|
|
1 0 0 0 0 0
|
72...95 %
|
60...91 %
|
18...54 %
|
|
|
|
|
|
|
Max- stop for V60 throttle valve positioner
▪ 18...54 %: OK
▪ Outside tolerance: Perform adaptation of the throttle valve control unit => Page 24-62
|
|
|
|
|
Emergency - running stop for V60 throttle valve positioner
▪ 60...91 %: OK
▪ Outside tolerance: Perform adaptation of the throttle valve control unit
▪ => Page24-62
|
|
|
|
Min- stop for V60 throttle valve positioner
▪ 72...95 %: OK
▪ Outside tolerance: Perform adaptation of the throttle valve control unit => Page 24-62
|
|
|
Learning demand display
▪ 100000: OK
▪ Other display: Perform adaptation of the throttle valve control unit => Page 24-62
|
Display Group 24 - Knock control:
|
Read measured value block 24
|
⇒
|
◂ Display readout
|
|
rpm
|
ms
|
° BTDC
|
5 crankshaft
|
|
|
|
|
|
|
Total ignition timing retardation for cylinders 1 to 4
|
|
|
|
|
Ignition timing
|
|
|
|
Engine load
|
|
|
Idling speed is shown in increments of 40
|
Notes on Display Group 24:
-
◆ As soon as symptoms of knocking are detected, the knock control must retard the ignition timing in order to prevent engine damage.
-
◆ However, the ignition timing retardation does increase the exhaust gas temperature. There is a risk of the catalytic converter overheating.
-
◆ Retarding the ignition timing in all the cylinders by, for example, 3 °CS has exactly the same effect as retarding it by 12 °CS in only one of the cylinders.
-
◆ To avoid overheating, at full load, from a total retardation of approx. 10 °CS, enrichment takes place to reduce the exhaust gas temperature.
Display Group 25; Boost pressure control at full load (test drive in 3rd gear at approx. 4000 rpm, coolant temperature not less than +85 °C)
Warning: The V.A.G 1551 fault reader must be operated by a second person.
|
Read measured value block 25
|
⇒
|
◂ Display readout
|
|
3.0...8.0
ms
|
0.0...8.0
ms
|
0.5...8.0
ms
|
0...99
%
|
|
|
|
|
|
|
Signal ratio (actuation) of the N75 solenoid valve for boost pressure control
▪ No specified value
▪ Constant 5 %: Boost pressure has open loop control => Interrogate the fault memory
|
|
|
|
|
Actual engine load (regulated by boost pressure to specified -engine load)
▪ As specified engine load after correction, display zone 2 (Tolerance±0.30 ms) OK
▪ Outside tolerance: Fault in boost pressure control => Page 24-34
|
|
|
|
Specified engine load after correction (reduced driver requirement due to knock control, altitude adaptation and intake air temperature)
▪ 0.00...8.00 ms: OK
|
|
|
Specified engine load before correction (driver's requirement indicated via accelerator pedal)
▪ 3.00...8.00 ms: OK
|
Display Group 26 - Idling air requirement:
|
Read measured value block 26
|
⇒
|
◂ Display readout
|
|
-10...+10
%
|
-1.1...+1.1
g/s
|
80...105
°C
|
800...920
rpm
|
|
|
|
|
|
|
Engine speed
|
|
|
|
|
Coolant temperature
|
|
|
|
Idling air mass (without gear engaged with automatic gearbox)
|
|
|
Idling speed control
|
Display Group 27, Load reduction by knock control at full load: (test drive in 3rd gear at approx. 4000 rpm, coolant temperature not less than +85°C)
Warning: The V.A.G 1551 fault reader must be operated by a second person.
|
Read measured value block 27
|
⇒
|
◂ Display readout
|
|
0...5
ms
|
0.5...8
ms
|
....
rpm
|
0...99
%
|
|
|
|
|
|
|
Signal ratio (actuation) of the -N75 solenoid valve for boost pressure control
▪ No specified value
▪ Constant 5 %: Boost pressure open loop control => Interrogate the fault memory
|
|
|
|
|
Engine speed
|
|
|
|
Engine load after reduction
|
|
|
Load reduction by knock control
|
Display Group 66 Only for vehicles with cruise control systems (CCS): Engine idling
|
Read measured value block 66
|
⇒
|
◂ Display readout
|
|
km/h
|
X X X X
|
km/h
|
X X X X
|
|
|
|
|
|
|
Switch settings for operating switch
0000= CCS switched on
0110= CCS switched off (switch engaged)
0010= CCS off (before the engagement point)
0100= Fix key depressed
1000= Key Mounting pulled
|
|
|
|
|
Specified driving speed (the last speed to be stored is displayed) until the CCS on the control switch switches off, switch engages in "OFF" or the engine is stopped)
|
|
|
|
Switch settings for brake, clutch and CCS released
1000= CCS released
1111= Brake depressed (brake light switch)
1111= Brake depressed (brake light switch)
1011= Clutch depressed
|
|
|
Actual driving speed
|
Notes on Display Group 66:
If the specified values are not reached, check the cruise control system (CCS).
=> Electrical system; Repair Group 01; Technical Bulletin No. 2
Display Group 98 - Adaptation of throttle valve control unit: Ignition switched on
|
Basic setting 98
|
⇒
|
◂ Display readout
|
|
0...5
V
|
0...5
V
|
Idling speed
|
ADP running
|
|
|
|
|
|
|
Adaptation status
▪ ADP running = Adaptation in progress
▪ ADP OK = Adaptation successfully completed
▪ ADP ERROR = Error has occurred in adaptation process: Check throttle valve control unit
|
|
|
|
|
Operating status
▪ Idling, part load, full load, overrun, enrichment
|
|
|
|
Potentiometer voltage for idle positioner
|
|
|
Throttle valve potentiometer voltage
|
Display Group 99 - Lambda control:
|
Read measured value block 99
|
⇒
|
◂ Display readout
|
|
...
rpm
|
...
°C
|
-10...+10
%
|
λ-control OFF
λ-control ON
|
|
|
|
|
|
|
Lambda control OFF/ON
▪ Basic setting 04: λ-Control OFF
▪ Read measured value block 08: λ-Control ON
|
|
|
|
|
Lambda control
|
|
|
|
Coolant temperature
|
|
|
Engine speed
|
Notes on Display Group 99:
-
◆ For defined fault finding, the lambda control is switched off when Display Group 99 is selected under "Basic setting 04" and switched when it is selected in "Reading measured value block 08".
-
◆ When function 04 "Basic setting" is left, the lambda control is automatically re-activated.
-
◆ 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 "Reading measured value block".
| 
