volkswagen Workshop Repair Guides

Volkswagen Workshop Service and Repair Manuals

Evaluating measured value blocks, display groups 10...29 -Ignition- > < Read measured value block
4LV injection and ignition system
Evaluating measured value blocks, display groups 0...6 -Basic functions
Evaluating measured value blocks, display groups 0...6 -Basic functions

Display group 1 -Basic functions-

Read measured value block 1

◂ Indicated on display

xxxx rpm

xx.x °C

xx.x %

xxxxxxxx

1

2

3

4

◂ Display zones

Specification

Evaluation

Adjustment conditions

11111111

Lambda regulation values

-15...15 %

=> Page 01-104

Coolant temperature

85...110 °C

=> Page 01-91

Engine speed (idling speed)
Vehicles with engine code AUA
Vehicles with engine code AUB
Vehicles with automatic gearbox


800...900 rpm1)
790...890 rpm1)
630...730 rpm1)


=> Page 01-90

     1)     Up-to-date specifications:

=> Exhaust emissions test binder

Significance of 8-digit number block

Significance if display = 1

1

2

3

4

5

6

7

8

Significance

1

Coolant temperature above 80 °C

1

Speed below 2000 rpm

1

Throttle valve closed

1

Lambda regulation OK.

1

Idling switch closed

1

Air conditioner compressor switched off

1

Catalyst hot (over 300 °C)

1

No faults recognised by self-diagnosis

Evaluating display group 1, display zone 1 - Engine speed (idling speed)

Appears on display

Possible fault cause

Fault elimination

Less than specification

- Throttle valve control part sticking or defective

- Check throttle valve control part
=> Page 24-43

- Air filter element heavily soiled

- Renew air filter element => Page 24-25

Greater than
specification

- Throttle valve control part sticking or defective

- Interrogate fault memory, => Page 01-16

- Large amount of unmetered air (cannot be compensated for by the idling stabilisation)

- Check intake air system for leaks
=> Page 24-85

- Check throttle valve control part
=> Page 24-43

- Perform idling check => Page 24-89

Evaluating display group 1, display zone 2 - Coolant temperature

Appears on display

Possible fault cause

Fault elimination

Less than 80 °C

- Engine too cold

- If necessary carry out test drive

- Coolant temperature sender or wiring to engine control unit

- Check coolant temperature sender

- Thermostat defective

- Check thermostat

More than 110 °C

- Radiator soiled

- Clean radiator

- Radiator fan not functioning

- Check function

- Thermostat defective

- Check thermostat

- Coolant temperature sender or wiring to engine control unit

- Check coolant temperature sender

Display group 2 -Basic functions-

▪ Engine running at idling speed

Read measured value block 2

◂ Indicated on display

xxxx rpm

xxx.x %

x.x ms

xxx mbar

1

2

3

4

◂ Display zones

Specification

Evaluation

Intake manifold pressure

240...420 mbar

=> Page 01-94

Injection period

2.0...4.0 ms

=> Page 01-93

Engine load

10...20 %

=> Page 01-103

Engine speed (idling speed)
Vehicles with engine code AUA
Vehicles with engine code AUB
Vehicles with automatic gearbox


800...900 rpm1)
790...890 rpm1)
630...730 rpm1)


=> Page 01-90

     1)     Up-to-date specifications:

=> Exhaust emissions test binder

Evaluating display group 2, display zone 3 - Injection period

Appears on display

Possible fault cause

Fault elimination

Less than 2.0 ms

- Large amount of fuel from the activated charcoal filter system

- Check activated charcoal filter solenoid valve 1 => Page , Final control diagnosis

- Incorrect injectors with greater throughput installed

- Check injectors => Page 24-71

- Check injector part number:
=> Parts micro-fiche

More than 4.0 ms

- Increased engine load due to electric consumers, air conditioner, gear selected or P.A.S. on full lock

- Eliminate increased load (air conditioner, power assisted steering etc.)

- Incorrect injectors with smaller throughput installed

- Check injectors => Page 24-71

- Check injector part number:
=> Parts micro-fiche

Evaluating display group 2, display zone 4 - Intake manifold pressure

Appears on display

Possible fault cause

Fault elimination

Less than 240 mbar

- Large amount of unmetered air between intake manifold and air cleaner

- Rectify unmetered air

More than 420 mbar

- Gear selected (automatic gearbox)

- Place selector lever in P or N

- Engine loaded due to ancillaries

- Eliminate load (air conditioner, power assisted steering etc.)

- Air filter element heavily soiled

- Renew air filter element => Page 24-25

Display group 3 -Basic functions-

▪ Engine running at idling speed

Read measured value block 3

◂ Indicated on display

xxxx rpm

xxx mbar

xx°

xx.x°BTDC

1

2

3

4

◂ Display zones

Specification

Evaluation

Ignition timing

0...10 ° BTDC

---

Throttle valve angle (potentiometer 1 -G187)

0...11 %

=> Page 01-104

Intake manifold pressure

240...420 mbar

=> Page 01-94

Engine speed (idling speed)
Vehicles with engine code AUA
Vehicles with engine code AUB
Vehicles with automatic gearbox


800...900 rpm1)
790...890 rpm1)
630...730 rpm1)


=> Page 01-90

     1)     Up-to-date specifications:

=> Exhaust emissions test binder

Display group 4 -Basic functions-

▪ Engine running at idling speed

Read measured value block 4

◂ Indicated on display

xxxx rpm

xx.xxx V

xxx.x °C

xxx.x °C

1

2

3

4

◂ Display zones

Specification

Evaluation

Intake air temperature

-30.0...120.0 °C

=> Page 01-99

Coolant temperature

80...110 °C

=> Page 01-98

Voltage supply for engine control unit

12.0...15.0 V

=> Page 01-97

Engine speed (idling speed)
Vehicles with engine code AUA
Vehicles with engine code AUB
Vehicles with automatic gearbox


800...900 rpm1)
790...890 rpm1)
630...730 rpm1)


=> Page 01-90

     1)     Up-to-date specifications:

=> Exhaust emissions test binder

Note on display zone 3:

The engine control unit will use the intake air temperature as a replacement value for an engine start (start temperature - replacement value) as soon as there is a fault stored in the fault memory, which affects the coolant temperature sender (G62). The temperature then rises according to a model stored in the control unit. When the engine has reached normal working temperature a fixed replacement value will be displayed after a certain period. This fixed value is also dependent upon the intake air temperature.

Note on display zone 4:

The total temperature range is given as the specification. The displayed value must be above ambient temperature.

Evaluating display group 4, display zone 2 - Control unit voltage supply

Appears on display

Possible fault cause

Fault elimination

Less than 12.000 V

- Alternator defective, battery heavily discharged

- Check alternator and battery voltage, charge battery:

- Battery heavily charged shortly after starting due to high charging current and current consumers

- Increase revs slightly for a few minutes and switch off current consumers

- Transfer resistance in the current supply or the engine control unit earth connection

- Check engine control unit voltage supply => Page 24-112

- Current draw when ignition is off

- Eliminate current draw

More than 15.000 V

- Voltage regulator on alternator defective

- Check voltage, replace regulator if necessary:

- Excess voltage due to jump starting or quick charging unit

- Interrogate fault memory => Page 01-16

Evaluating display group 4, display zone 3 - Coolant temperature

Appears on display

Possible fault cause

Fault elimination

Less than 80 °C

- Engine too cold

- If necessary carry out test drive

- Coolant temperature sender or wiring to engine control unit

- Check coolant temperature sender

- Thermostat defective

- Check thermostat

Greater than 110 °C

- Radiator soiled

- Clean radiator

- Radiator fan not functioning

- Check function
=> Binder Electrical system

- Thermostat defective

- Check thermostat

- Coolant temperature sender or wiring to engine control unit

- Check coolant temperature sender

Constant -40.0 °C

- Wiring open circuit or short to positive

- Check coolant temperature sender

Constant 120.0 °C

- Short to earth

Evaluating display group 4, display zone 4 - Intake air temperature

Appears on display

Possible fault cause

Fault elimination

Constant -40.0 °C

- Wiring open circuit or short to positive

- Check intake air temperature sender

Constant 120.0 °C

- Short to earth

Display group 5 -Basic functions-

▪ Engine running at idling speed

Read measured value block 5

◂ Indicated on display

xxxx rpm

xxx.x %

xxx km/h

Text

1

2

3

4

◂ Display zones

Specification

Evaluation

Operating mode (idling, part throttle, enrichment, overrun)


Idling

---

Road speed

0 km/h

---

Engine load

10...20 %

=> Page 01-103

Engine speed (idling speed)
Vehicles with engine code AUA
Vehicles with engine code AUB
Vehicles with automatic gearbox


800...900 rpm1)
790...890 rpm1)
630...730 rpm1)


=> Page 01-90

     1)     Up-to-date specifications:

=> Exhaust emissions test binder

Display group 6 -Basic function-

▪ Engine running at idling speed

Read measured value block 6

◂ Indicated on display

xxxx rpm

xxx.x %

xxx.x °C

xx.x %

1

2

3

4

◂ Display zones

Specification

Evaluation

Elevation correction factor

-30.0...5.0 %

---

Intake air temperature

-40...120.0 °C

=> Page 01-99

Engine load

10...20 %

=> Page 01-103

Engine speed (idling speed)
Vehicles with engine code AUA
Vehicles with engine code AUB
Vehicles with automatic gearbox


800...900 rpm1)
790...890 rpm1)
630...730 rpm1)


=> Page 01-90

     1)     Up-to-date specifications:

=> Exhaust emissions test binder

Note on display zone 3:

The total temperature range is given as the specification. The displayed value must be above ambient temperature.

Evaluating measured value blocks, display groups 10...29 -Ignition- > < Read measured value block