seat Workshop Repair Guides

SEAT Workshop Service and Repair Manuals

Evaluating measured value blocks, display groups 10...29 -Ignition- > < Performing final control diagnosis
Motronic injection and ignition system (1.8 l engine)
Evaluating measured value blocks, display groups 0...9 -Basic functions-
Evaluating measured value blocks, display groups 0...9 -Basic functions-

Display group 1 -Basic functions-

▪ Engine running at idling speed

Read measured value block 1

◂ Indicated on display

xxxx rpm

xx.x °C

x.x %

xxxxxxxx

1

2

3

4

◂ Display zones

Specification

Evaluation

Adjustment conditions for basic setting

1x111111

Lambda regulator before catalyst

-25.0...25.0 %

=> Page 01-131

Coolant temperature

80...110 °C

=> Page 01-115

Engine speed (idling speed):

760...880 rpm

=> Page 01-109

Significance of 8-digit number block for readiness code

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

Operating mode: idling speed

1

Air conditioner compressor switched off

1

Not relevant

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 760 rpm

- Throttle valve control unit sticking or defective

- Check throttle valve control part
=> Page 24-38

- Perform idling check => Page 24-79

Greater than 880 rpm

- Operating mode: idling speed not recognised

- Interrogate fault memory, => Page 01-18

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

- Check intake air system for leaks
=> Page 24-76

- Throttle valve control part sticking/defective

- Check throttle valve control part
=> Page 24-38

- Perform idling check => Page 24-79

Display group 2 -Basic functions- Air mass meter

▪ Engine running at idling speed

Read measured value block 2

◂ Indicated on display

xxxx rpm

xxx %

x.x ms

x.x g/s

1

2

3

4

◂ Display zones

Specification

Evaluation

Air mass drawn in

1.0...5.0 g/s

=> Page 01-111

Injection period

2.0...3.5 ms

=> Page 01-111

Engine load

10...25 %

=> Page 01-120

Engine speed (idling speed):

760...880 rpm

=> Page 01-109

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 01-88, Final control diagnosis

- Incorrect injectors with greater throughput installed

- Check injection rate => Page 24-60

Greater than 3.5 ms

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

- Eliminate increased load (air conditioning, P.A.S, etc.)

Evaluating display group 2, display zone 4 - Air mass drawn in

Appears on display

Possible fault cause

Fault elimination

Less than 1.0 g/s

- Large amount of unmetered air between intake manifold and air mass meter

- Rectify unmetered air

Greater than 5.0 g/s

- Gear selected (automatic gearbox)

- Place selector lever in P or N

- Engine loaded due to ancillaries

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

Display group 3 -Basic function- Air mass meter

▪ Engine running at idling speed

Read measured value block 3

◂ Indicated on display

xxxx rpm

x.xx ms

x.x %

xx.x°BTDC

1

2

3

4

◂ Display zones

Specification

Evaluation

Ignition timing

5...15° BTDC

---

Throttle valve angle (potentiometer 1 -G187)

---

---

Air mass drawn in

1.0...5.0 g/s

=> Page 01-111

Engine speed (idling speed):

760...880 rpm

=> Page 01-109

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

-40,5...135°C

=> Page 01-116

Coolant temperature

80...110 °C

=> Page 01-115

Voltage supply for engine control unit

11.5...14.5 V

=> Page 01-114

Engine speed (idling speed):

760...880 rpm

=> Page 01-109

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 11.5 V

- Alternator defective, battery heavily discharged

- Check alternator and battery voltage, charge battery:
=> Electrical system: Repair group 27

- 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 24-103

- Current draw when ignition is off

- Eliminate current draw

Greater than 14.5 V

- Voltage regulator on alternator defective

- Check voltage regulator, replace if necessary:

- Excess voltage due to jump starting or quick charging unit

- Interrogate fault memory => Page 01-18

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

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 -45.0 °C

- Open circuit or short to positive

- Check coolant temperature sender

Constant 143 °C

- Short to earth

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

Appears on display

Possible fault cause

Fault elimination

Constant -44.0 °C

- Open circuit or short to positive

- Check intake air temperature

Constant 143 °C

- Short between wires 1 and 2 or to earth

Display group 5 -Basic functions-

▪ Engine running at idling speed

Read measured value block 5

◂ Indicated on display

xxxx rpm

xxx %

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...25 %

=> Page 01-120

Engine speed (idling speed):

760...880 rpm

=> Page 01-109

Display group 6 -Basic function-

▪ Engine running at idling speed

Read measured value block 6

◂ Indicated on display

xxxx rpm

xxx %

xxx.x °C

xx.x %

1

2

3

4

◂ Display zones

Specification

Evaluation

Elevation correction factor

-100.0...100.0 %

---

Intake air temperature

-40.5...135 °C

=> Page 01-116

Engine load

10...25 %

=> Page 01-120

Engine speed (idling speed):

760...880 rpm

=> Page 01-109

Note on display zone 3:

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

Note on display zone 4:

The entire range is given as specification. The display value lies between -30 % (ca. 3000 m elevation) and 0 % (ca. 0 m elevation).

Evaluating measured value blocks, display groups 10...29 -Ignition- > < Performing final control diagnosis