volkswagen Workshop Repair Guides

Volkswagen Workshop Service and Repair Manuals

Evaluating measured value blocks, display grps 30...49, 99 -Lambda regulation- > < Evaluating measured value blocks, display groups 0...9 -Basic functions-
Motronic inj. and ignition system (2-valve, roller rocker finger)
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 %

xxx.x %

xx.x°BTDC

1

2

3

4

◂ Display zones

Specification

Evaluation

Ignition angle

-5.0...10.0 ° BTDC

---

Throttle valve angle
(Potentiometer 1 -G187)


0.2...5.0 %

Engine load

15.0...30.0 %

=> Page 01-97

Engine speed (idling speed)

600...800 rpm

=> Page 01-85

Note on display zone 3:

With the accelerator pedal floored the display value must be approx. 100.0 %.

Evaluating display group 10, display zone 2 - Engine load

Appears on display

Possible fault cause

Fault elimination

Less than 15.0 %

- Lesser values can only occur when driving in overrun


---

Larger than 30.0 %

- Rough idling (not running on all cylinders)

- Check injectors => Page 28-1

- Throttle valve control part defective

- Check throttle valve control part
=> Page 24-46

- Electric consumers switched on

- Switch off electric consumers

- Steering wheel at full lock

- Set steering wheel to centre position

Evaluating display group 10, display zone 3 - Throttle valve angle potentiometer 1

Appears on display

Possible fault cause

Fault elimination

More than 5 %

- Engine control unit not adapted to throttle valve control part

- Adapt engine control unit to throttle valve control part => Page 24-141

- Throttle valve potentiometer in throttle valve control part defective

- Check throttle valve control part
=> Page 24-46

- Throttle valve sticking

- Eliminate cause

Only engines conforming to EU 4 standard (engine code AKP, AUC, AUD)

Display group14 -Ignition- Misfire recognition total

▪ Whilst driving

Read measured value block 14

◂ Indicated on display

xxxx rpm

xx.x %

xxx

Text

1

2

3

4

◂ Display zones

Specification

Evaluation

Misfire recognition
(activated, blocked)


activated


---

Misfire total

0

=> Page 01-100

Engine load

15.0...100.0 %

---

Engine speed

600...5700 rpm

---

Evaluating display group 14, display zone 3 - Total number of misfires

Appears on display

Possible fault cause

Fault elimination

More than 0

- Spark plug defective
- Spark plug connector defective
- Ignition coil defective
- Ignition coil output stage defective

- Check spark plugs and ignition/HT wiring with connector => Page 28-13

- Injector defective

- Check injectors
=> Page 24-76

Only engines conforming to EU 4 standard (engine code AKP, AUC, AUD)

Display group 15 -Ignition- Misfire recognition Cyl. 1 to Cyl. 3

▪ Whilst driving

Read measured value block 15

◂ Indicated on display

xxx

xxx

xxx

Text

1

2

3

4

◂ Display zones

Specification

Evaluation

Misfire recognition
(activated, blocked)


activated


---

Misfire Cyl. 3

0

=> Page 01-103

Misfire Cyl. 2

0

=> Page 01-103

Misfire Cyl. 1

0

=> Page 01-103

Only engines conforming to EU 4 standard (engine code AKP, AUC, AUD)

Display group 16 -Ignition- misfire recognition Cyl. 4

▪ Whilst driving

Read measured value block 16

◂ Indicated on display

xxx

---

---

Text

1

2

3

4

◂ Display zones

Specification

Evaluation

Misfire recognition
(activated, blocked)


activated


---

Misfire Cyl. 4

0

=> Page 01-103

Evaluating display group 15 display zones 1 to 3 or display group 16 display zone 1 - Misfire recognition Cyl. 1 to Cyl. 4

Appears on display

Possible fault cause

Fault elimination

More than 0

- Spark plug defective
- Spark plug connector defective
- Ignition coil defective
- Ignition coil output stage defective

- Check spark plugs and ignition/HT wiring with connector => Page 28-13

- Injector defective

- Check injectors
=> Page 24-76

Display group 20 -Ignition- Knock control Cyl. 1 to Cyl. 4

▪ Whilst driving

Read measured value block 20

◂ Indicated on display

xx.x °CA

xx.x °CA

xx.x °CA

xx.x °CA

1

2

3

4

◂ Display zones

Specification

Evaluation

Cyl. No. 4 retardation of ignition by knock control


0.0...12.0 °CA

=> Page 01-105

Cyl. No. 3 retardation of ignition by knock control


0.0...12.0 °CA

=> Page 01-105

Cyl. No. 2 retardation of ignition by knock control

0.0...12.0 °CA

=> Page 01-105

Cyl. No. 1 retardation of ignition by knock control

0.0...12.0 °CA

=> Page 01-105

Note on display zones 1 to 4:

Display value should be 0.0 °CA at idling speed.

Evaluating display group 20, display zones 1 to 4 - Cyl. 1 to Cyl. 4 ignition retardation

Appears on display

Possible fault cause

Fault elimination

All cylinders greater than 12.0 °CA

- Knock sensor defective

- Check knock sensor => Page 28-20

- 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 sensor => Page 28-20

- Engine damaged

- Check compression pressures:

- Ancillary components on engine loose

- Tighten ancillary components

Display group 22 -Ignition- Cyl. 1 and Cyl. 2 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

Cyl. No. 2 retardation of ignition timing by knock control


0.0...12.0 °CA

=> Page 01-108

Cyl. No. 1 retardation of ignition timing by knock control


0.0...12.0 °CA

=> Page 01-108

Engine load

15.0...100.0 %

---

Engine speed

600...5700 rpm

---

Note on display zones 3 and 4:

The display value should be 0.0 °CA at idling speed.

Display group 23 -Ignition- Cyl. 3 and Cyl. 4 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

Cyl. No. 4 retardation of ignition by knock control


0.0...12.0 °CA

=> Page 01-108

Cyl. No. 3 retardation of ignition by knock control


0.0...12.0 °CA

=> Page 01-108

Engine load

15.0...100.0 %

---

Engine speed

600...5700 rpm

---

Note on display zones 3 and 4:

The display value should be 0.0 °CA at idling speed.

Evaluating display groups 22/23, display zones 3 and 4 - Retardation of ignition

Appears on display

Possible fault cause

Fault elimination

All cylinders greater than 12.0 °CA

- Knock sensor defective

- Check knock sensor => Page 28-20

- 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 sensor => Page 28-20

- Engine damaged

- Check compression pressures:

- Ancillary components on engine loose

- Tighten ancillary components

Display group 28 -Ignition- knock control

▪ Whilst driving

▪ Control unit in mode 04-Basic settings

Read measured value block 28

◂ Indicated on display

xxxx rpm

xx.x %

xxx.x °C

Text

1

2

3

4

◂ Display zones

Specification

Evaluation

Knock sensor test result
(Test On / Test OFF / Sys. OK. / Sys. n.OK.


Sys. OK.


---

Coolant temperature

80.0...110.0 °C

=> Page 01-92

Engine load

15.0...100.0 %

---

Engine speed

2200...5700 rpm

---

Evaluating measured value blocks, display grps 30...49, 99 -Lambda regulation- > < Evaluating measured value blocks, display groups 0...9 -Basic functions-