Volkswagen Golf / Golf GTI / Jetta. Manual — part 169

01-218

Display group 31 - Oxygen Sensor (O2S) control constantly operating Oxygen
Sensors

Engine running at idle

Read measured value
block 31

Indicated on

display

x.xx

x.xx

---

---

1

2

3

4

Display zones

Specification

Evaluation

No display

---

---

No display

---

---

Oxygen Sensor (O2S) control,
specification

1.00

---

Oxygen Sensor (O2S) control, current
value

0.96...1.04

---

Measured value (data) blocks

01-219

Display group 32 - Oxygen Sensor (O2S) control - Oxygen Sensor (O2S) learned
values before Three Way Catalytic Converter (TWC)

Engine running at idle

Read measured
value block 32

Indicated on

display

xx.x

%

xx.x

%

---

---

1

2

3

4

Display zones

Specification

Evaluation

No display

---

---

No display

---

---

Oxygen Sensor (O2S) learned
value at part load (multiple
active)

before Three Way Catalytic
Converter (TWC)

-10.0...10.0 %

Page 01-221

Oxygen Sensor (O2S) learned value at
idle (additive)

before Three Way Catalytic Converter
(TWC)

-5.4...5.4 %

Page 01-221

Measured value (data) blocks

01-220

Note on display zones 1 and 2:

Low values indicate that the engine is running too rich and therefore the Oxygen

Sensor (O2S) control is leaning the mixture.

High values indicate that the engine is running too lean and therefore the Oxygen

Sensor (O2S) control enriches the mixture.

If there is no voltage supply to the control module all the values learned will be reset.

DTC memory, checking and erasing

Page 01-23

.

add = additive - The effects of the malfunction (e.g. unmetered air) will reduce as the

engine speed increases. The injection period will be modified by a fixed amount for
additive learned values. This amount is not dependent upon the basic injection
period.

mul. = multiple active - The effects of the malfunction (e.g. faulty fuel injector) will

increase as the engine speed increases. A multiple active learned value is a
proportional change to the injection period. This change is dependent on the basic
injection period.

Measured value (data) blocks

01-221

Evaluating display group 32, display zones 1 and 2 - Oxygen Sensor (O2S) learned
values before Three Way Catalytic Converter (TWC)

Appears on

display

Possible cause

Corrective action

Low Oxygen

Sensor (O2S)

learned

values

Low learned values at idling

but with normal learned
values at part throttle/load:
possible oil dilution (high
level of fuel in oil)

- Disappears after
freeway/expressway driving or oil
change

Fuel injector leaking

- Check fuel injectors

Page 24-97

Fuel pressure too high

- Check fuel pressure control and
holding pressure

Page 24-110

Evaporative Emission

(EVAP) Canister Purge
Regulator Valve -N80-
permanently open

Repair Manual, 2.8 Liter VR6 4V

Engine Mechanical, Engine Code(s):
BDF; Repair Group 20

- Check Evaporative Emission
(EVAP) Canister Purge Regulator
Valve -N80-

Page 01-100

,

Output Diagnosis Test Mode (DTM)

- Check Evaporative Emissions
(EVAP) Canister system:

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

Continuation

next Page

Measured value (data) blocks