Volkswagen Golf / Golf GTI / Jetta. Manual — part 220

24-134

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).

If the specification is not obtained:

- Press

button.

- Check Heated Oxygen Sensor (HO2S)

Page

24-38

.

If the specification is obtained:

- Change to display group 32 as follows:

- Press -C- button.

Read measured value block

Input display group number XXX

Indicated on display:

- Press buttons -0-, -3- and -2- for "Display group

number 32" and confirm entry with -Q- button.

Read measured value block 32

1

2

Indicated on display: (1 to 2

display zones)

- Check Oxygen Sensor learned values at idle

speed (additive) in display zone 1.

Specification: -5.4 to 5.4 %

Functions, checking

24-135

- Check Oxygen Sensor learned values at part

load (multiple active) in display zone 2.

Specification: -10.0 to 10.0%

If the specifications are not obtained:

- Press

button.

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

output" and confirm entry with -Q- button.

- Switch off ignition.

- Evaluate display group 32

Page 01-221

.

If the specifications are obtained:

- Change to display group 33 as follows:

VAG 1551: Press button -3-

VAG 1552: Press button

Read measured value block 33

1

2

Indicated on display: (1 to 2

display zones)

- Check Oxygen Sensor control in display zone 1.

Display must fluctuate in range of -10.0 to 10.0%

by at least 2%.

- Check Oxygen Sensor control in display zone 2.

Display must fluctuate in range of 1.400 to 1.600

V.

Functions, checking

24-136

If the displays in display zones 1 and 2 fluctuate:

- Press

button.

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

output" and confirm entry with -Q- button.

- Switch off ignition.

If one or both of the displays in zones 1 and 2

display a value constantly:

- Press

button.

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

output" and confirm entry with -Q- button.

- Switch off ignition.

- Check wiring of Heated Oxygen Sensor (HO2S)

Page 24-138

.

If the Oxygen Sensor control in display zone 1

does not fluctuate in the stated range:

- Press

button.

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

output" and confirm entry with -Q- button.

Functions, checking

24-137

- Road test vehicle to remove possible

contaminates 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 by at least 2%:

- Check Heated Oxygen Sensor (HO2S) for aging

Page 24-150

.

Possible causes of Diagnostic Trouble Code

(DTC) when continuous regulation of sensor
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