Volkswagen Golf / Golf GTI / Jetta. Manual — part 224

24-150

Heated Oxygen Sensor
(HO2S), checking aging

Special tools and equipment

Note:

All functions which could previously
be performed with VAG 1551/1552
can also be performed with the VAS
5051.

Test requirements

VAG 1551 Scan tool (or VAG

1552) with VAG 1551/3 adapter
cable

The fuses must be OK.

The battery voltage must be at

least 11.5 V.

All electrical accessories, e.g.

lights and rear window defroster
must be switched off.

If the vehicle is equipped with air

conditioning, it must be turned
off.

Functions, checking

24-151

Selector lever must be in position "P" or "N"

on vehicles with an automatic transmission.

Exhaust system between Three Way

Catalytic Converter (TWC) and cylinder head
must be free of leaks.

Engine Coolant Temperature (ECT) must be

at least 85 C, display group 1, display
zone 2.

Three Way Catalytic Converter (TWC)

temperature must be at least 380 C,

display group 34, display zone 2.

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 -4- for function "Initiate

basic setting" and confirm entry with -Q- button.

Basic setting

Input display group number XXX

Indicated on display:

- Press buttons -0-, -3- and -4- for "Display group

number 34" and confirm entry with -Q- button.

Functions, checking

24-152

System in basic setting 34

1

2

3

4

Indicated on display: (1 to 4

display zones)

When performing this test the Three
Way Catalytic Converter (TWC)
temperature in display zone 2 must
be at least 380 C.

Note:

This process can take approx. 90
seconds.

- Depress brake pedal and hold.

- Depress accelerator down to wide

open throttle position.

Engine speed will be increased by

Motronic Engine Control Module
(ECM) -J220- to approx. 2300
rpm.

- Depress brake pedal and

accelerator down and hold until
display in display zone 4 jumps
from "Test OFF" to "Test ON."

- Depress and hold brake pedal

and accelerator until display zone
4 displays specification "B1-P1
OK.".

- Release brake and accelerator

pedals.

- Press

button.

- Press buttons -0- and -6- for

function "End output" and confirm
entry with -Q- button.

Functions, checking

24-153

If the display does not indicate as described:

- 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 display does not indicate as described

again:

- Check Oxygen Sensor (O2S) and Oxygen

Sensor control before Three Way Catalytic
Converter (TWC)

Page 24-131

Functions, checking