Volkswagen Golf / Golf GTI / Jetta. Manual — part 168

01-214

Evaluating display groups 22 to 24, display zones 3 and 4 - Ignition timing
retardation cyl. 1 to 6

Appears on

display

Possible cause

Corrective action

All cylinders

between

8.0...15.0 CA

and at the same

display values

Knock sensor

faulty

Connector

corroded

- Check knock sensors

Page 28-30

Knock sensor

incorrectly
tightened

- Loosen knock sensor and tighten to
20 Nm

Accessories on

engine loose

- Tighten accessories

Poor fuel quality

- Change type of fuel

One cylinder

deviates greatly from

the others

Connector

corroded

- Check knock sensors

Page 28-30

Engine damaged

Repair Manual, 2.8 Liter VR6 4V

Engine Mechanical, Engine Code(s):
BDF; Repair Group 15

- Check compression pressures:

Accessories on

engine loose

- Tighten accessories

Measured value (data) blocks

01-215

Display group 28 - Ignition - Knock control

Control module in function "04-Basic setting"

Vehicle stationary, engine running at increased idle speed (only with brake and

accelerator pedals depressed)

System in basic
setting 28

Indicated on display

xxxx
rpm

xxx.x

%

xxx.x

C

Text

1

2

3

4

Display zones

Specification

Evaluation

Result of knock control
diagnosis

(Test ON / Test OFF /
Sys. OK. / Sys. n.OK.)

Syst. OK.

---

Engine coolant temperature

85.0...110.0

C

Page 01-

195

Engine load

12.0...100.0 %

---

Engine speed

Approx. 2300

rpm

---

Measured value (data) blocks

01-216

Measured value blocks, display groups 30...33, 99 - Oxygen Sensor (O2S)
control, evaluating

Display group 30 - Oxygen Sensor (O2S) control

Engine running at idle

Read measured value
block 30

Indicated on display

xxx

xxx

---

---

1

2

3

4

Display zones

Specification Evaluation

No display

---

---

No display

---

---

Oxygen Sensor (O2S) control status after
Three Way Catalytic Converter (TWC)

Three Way Catalytic Converter

(TWC) temperature at least 380.0

C (

display group 34, display zone

2)

111

Page 01-

217

Oxygen Sensor (O2S) control status before
Three Way Catalytic Converter (TWC)

Three Way Catalytic Converter (TWC)

temperature at least 380.0 C (

display

group 34, display zone 2)

111

Page 01-

217

Note on display zone 2:

The 3rd character in the digit number block will not be set to 1 until in part load range.

Measured value (data) blocks

01-217

Significance of characters in 3 digit number block, display zones 1 and 2 - Status
of Oxygen Sensor (O2S) control before and after Three Way Catalytic Converter
(TWC)

Significance if display = 1

1 2 3

Significance

1 Oxygen Sensor (O2S) control active

1

Oxygen Sensor (O2S) operationally ready

1

Oxygen Sensor (O2S) heating on

Note:

Depending on the status of the Oxygen Sensor (O2S) control, 0 or 1 may appear

alternately in the 3 digit block, but the Oxygen Sensor (O2S) must always be
operationally ready.

The 1 set for the Oxygen Sensor (O2S) heating may sporadically be 0 because the

heating is pulsed.

Measured value (data) blocks