Volkswagen Golf / Golf GTI / Jetta. Manual — part 222

24-142

Functional check

- Connect VAG 1551 Scan tool (or VAG 1552)

and select engine electronics control module
with "Address word" 01. Engine must be running
at idle speed: ((VAG 1551 and Motronic Engine
Control Module (ECM) -J220-, connecting and
selecting

Page 01-12

).

Rapid data transfer

HELP

Select function XX

Indicated on display:

- Press buttons -0- and -8- for function "Read

measured value (data) block" and confirm entry
with -Q- button.

Read measured value block

Input display group number XXX

Indicated on display:

- Press buttons -0-, -3- and -0- for "Display group

number 30" and confirm entry with -Q- button.

Read measured value block 30

1

2

Indicated on display: (1 to 2

display zones)

- Check Oxygen Sensor control status after Three

Way Catalytic Converter (TWC) (display zone 2).

Specification: 111

Significance of figures in 3 digit number block

Page 01-217

.

Functions, checking

24-143

Note:

The bits in display zone 1 will not be set to 1 until
the Three Way Catalytic Converter (TWC)
temperature rises above 380 C (

display

groups 34, display zone 2) and a part load signal
is recognized by the Motronic Engine Control
Module (ECM) -J220-.

If the specification is not obtained:

- Press

button.

- Check Oxygen Sensor (O2S) heating after

Three Way Catalytic Converter (TWC)

Page

24-45

.

If the specification is obtained:

- Change to display group 36 as follows:

- Press -C- button.

Read measured value block

Input display group number XXX

Indicated on display:

- Press buttons -0-, -3- and -6- for "Display group

number 36" and confirm entry with -Q- button.

Read measured value block 36

1

2

3

4

Indicated on display: (1 to 4

display zones)

- Check Oxygen Sensor (O2S) voltage after

Three Way Catalytic Converter (TWC) in display
zone 1:

Specification: 0.100 to 0.900 V (must fluctuate

slightly)

Functions, checking

24-144

If the display in display zone 1 fluctuates:

- Press

button.

- Press buttons -0- and -6- for function "End

output" and confirm entry with -Q- button.

- Switch off ignition.

If the display in display zone 1 remains

constantly at a value:

- Press

button.

- Press buttons -0- and -6- for function "End

output" and confirm entry with -Q- button.

- Switch off ignition.

- Check basic voltage of Oxygen Sensor (O2S)

Behind Three Way Catalytic Converter (TWC) -
G130-

Page 24-146

.

- Check Oxygen Sensor (O2S) wiring of Oxygen

Sensor (O2S) Behind Three Way Catalytic
Converter (TWC) -G130-

Page 24-148

.

If the Oxygen Sensor control in display zone 1

does not fluctuate in the stated range:

- Press

button.

Functions, checking

24-145

- Press buttons -0- and -6- for function "End

output" and confirm entry with -Q- button.

- Road test vehicle to remove possible residue on

Oxygen Sensor (O2S) and repeat check.

Observe the valid safety precautions when

performing a road test

Page 24-33

.

If the specifications in display zone 1 are not

obtained even after a road test, or the value does
not fluctuate:

- Check Oxygen Sensor (O2S) Behind Three Way

Catalytic Converter (TWC) -G130- for aging

Page 24-154

Possible causes of Diagnostic Trouble Code

(DTC) if sensor regulation frequency is too
slow:

The slots or holes in sensor body are blocked

The sensor breather hole in area of connecting

cable is blocked

The sensor has been overheated (glazed)

The sensor has been damaged by leaded

fuel

Functions, checking