Volkswagen Golf / Golf GTI / Jetta. Manual — part 170

01-222

Appears on

display

Possible cause

Corrective action

High Oxygen

Sensor

(O2S)

learned

values

High learned values at idle, not so

high learned values at part throttle:
Possible unmetered air in area of
intake manifold

- Check intake air system for
leaks

Page 24-121

Unmetered air between Mass Air

Flow (MAF) Sensor -G70- and
throttle valve

- Repair cause

Fuel injector blocked

- Check fuel injectors

Page

24-97

Fuel pressure too low

- Check fuel pressure control
and holding pressure

Page

24-110

Mass Air Flow (MAF) Sensor -G70-

faulty

- Check Mass Air Flow (MAF)
Sensor -G70-

Page 24-52

Oxygen Sensor (O2S) heating

faulty or Oxygen Sensor (O2S)
contaminated

- Check Oxygen Sensor
(O2S) heating before Three
Way Catalytic Converter
(TWC)

Page 24-38

Unmetered air at exhaust manifold

gasket

Repair Manual, 2.8 Liter

VR6 4V Engine Mechanical,
Engine Code(s): BDF; Repair
Group 26

- Check exhaust system for
leaks:

Measured value (data) blocks

01-223

Display group 33 - Oxygen Sensor (O2S) control - Oxygen Sensor (O2S) learned
values before Three Way Catalytic Converter (TWC)

Engine running at idle

Read measured
value block 33

Indicated on

display

xx.x

%

x.xxx

V

---

---

1

2

3

4

Display zones

Specification

Evaluation

No display

---

---

No display

---

---

Oxygen Sensor (O2S) voltage,
Oxygen Sensor (O2S) before
Three Way Catalytic Converter
(TWC)

1.400...1.600 V

Page 01-

225

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

-10.0...10.0 %

Page 01-

224

Note on display zone 1:

The display must swing around 0.0%. If 0.0% is constantly displayed, the Oxygen
Sensor (O2S) control has switched from control to control because a malfunction has
occurred in the Oxygen Sensor (O2S) control. Check DTC memory

Page 01-23

, DTC

memory, checking and erasing

Measured value (data) blocks

01-224

Evaluating display group 33, display zone 1 - Oxygen Sensor (O2S) control before
Three Way Catalytic Converter (TWC)

Appears on

display

Possible cause

Corrective action

Outside

tolerance

range

Minus range: Mixture too rich,

Oxygen Sensor (O2S) control
weakens mixture

Positive range: Mixture too lean,

Oxygen Sensor (O2S) control
enriches mixture

- Wait 30 seconds until
display has stabilized

Oxygen Sensor (O2S) learned

value on limit

- Check Oxygen Sensor
(O2S) learned value in
display group 32

Fuel injector faulty

- Check fuel injectors

Page 24-97

Unmetered air

- Check intake air system for
leaks

Page 24-121

Measured value (data) blocks

01-225

Evaluating display group 33, display zone 2 - Oxygen Sensor (O2S) control before
Three Way Catalytic Converter (TWC)

Appears

on display

Possible cause

Corrective action

Constant

1.5 V

Wiring open circuit via: Oxygen

Sensor (O2S), sensor wiring,
Ground (GND) wiring, Motronic
Engine Control Module (ECM) -
J220-

- Check Oxygen Sensor (O2S)
heating before Three Way
Catalytic Converter (TWC)

Page 24-138

Measured value (data) blocks