1997 AUDI A4 AFC Engine On Board Diagnostic Multiport Fuel Injection Workshop Manual

01-189
Display group 010 Display
shows Specified display value
Designation
Basic setting
10
1 2 3 4 Difference between display values 1 and 2
less than 8% 1 = Total of oxygen sensor control (bank 1) and momentary
oxygen sensor learning value (bank 1)
2 = Total of oxygen sensor control (bank 2) and momentary
oxygen sensor learning value (bank 2)

At times greater than 0.6 V and/or less than
0.3 V (display must fluctuate) 3 = Voltage signal-bank 1 heated oxygen sensor 1
4 = Voltage signal-bank 2 heated oxygen sensor 1 Note:
The total of the oxygen sensor control and oxygen sensor learning value shows the total effect of the oxygen sensor control.
Bank differences can be evaluated directly by comparing display field 1 with display field 2.
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01-190
Test table display group 010 Display
fields Display on VAG 1551 scan tool
Malfunction cause
Malfunction repair
1/2 Difference between display value
1 (bank 1) and display value 2
(bank 2) greater than 8%
Spark plug faultyIntake air leak on one side Fuel injectors faulty - Repair cause
- Check DTC memory page 01
-13

and/or check fuel injectors page 24-
29


Heated Oxygen Sensor
(HO2S) faulty (dirty) - Check DTC memory page 01
-13

and/or display fields 3 and 4

Mechanical engine basic
setting (valve/camshaft
timing) not OK
Repair Manual, 2.8 Liter V6 2V
Engine Mechanical, Engine Code(s): AFC, Repair Group 13
- Check valve/camshaft timing
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01-191

Display
fields Display on VAG 1551 scan tool
Malfunction cause
Malfunction repair
3/4 Display does not fluctuate-constant
between 0.0 - 0.3 V and/or between
0.6 - 0.9 V
Fuel injector faulty- Check fuel injectors page 24
-29

Spark plug faultyLarge intake air leak Engine Coolant Temperature
(ECT) sensor -G62- faulty EVAP canister purge
regulator valve -N80- - Check spark plug
- Repair cause
- Check DTC memory page 01
-13

and/or check -G62-
- Check using output diagnostic test
mode page 01
-145
and/or check -
N80-

Heated Oxygen Sensor
(HO2S) -G39- faulty or dirty Oxygen Sensor (O2S) heater
-Z19- does not function - Check DTC memory page 01
-13

and/or check -G39-
- Check -Z19- page 24
-49

Fuel system pressure too
high or too low - Check fuel pressure regulator and
residual pressure page 24
-20


Constant 2.550 V Short to positive (B+) through:
Heated Oxygen Sensor
(HO2S) -G39- wiring Engine Control Module
(ECM) -J192- - Check -G39- page 24
-49Pa
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continued
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01-192

Display
fields Display on VAG 1551 scan tool
Malfunction cause
Malfunction repair
3/4
Constant value between 0.350 -
0.450 V Open circuit in:
Heated Oxygen Sensor (HO2S) -G39-
wiring Engine Control Module (ECM) -J192-- Check -G39- page
24
-49


Constant 0.000 V Short to ground in:
Heated Oxygen Sensor (HO2S) -G39-
wiring Engine Control Module (ECM) -J192-- Check -G39- page
24
-49


Notes on display field 4:
The display value at times must drop below 0.3 V
and exceed 0.6 V. Display values less than 0.40
V indicate lean condition; greater than 0.40 V
indicate rich condition.

HO2S voltage U (mV) vs. Lambda ( ) A - HO2S voltage (mV) high
Rich mixture (fuel excess or lack of air)
High CO value
B - Oxygen sensor probes voltage (mV) low
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Lean mixture (lack of fuel or excess air)
Low CO value
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01-193
Display group 011 Display
shows Specified display
value Designation
Basic setting
11
1 2 3 4 ... BTDC
1 = Ignition timing point without knock control and without idle speed control

... BTDC 2 = Ignition timing point with knock control and digital idle speed control (average
value for all cylinders)

_._ crankshaft 3 = Ignition timing point access to digital idle speed control
0 and/or 1 4 = Closed Throttle Position (CTP) switch function:
Open = 0; Closed = 1
Notes on display field 1:

At idle-Closed Throttle Position (CTP) switch closed-an ignition timing point of 12 BTDC is displayed. When the engine speed is increased-CTP switch open-the current ignition timing point is displayed without knock control
and without digital idle speed control.
Notes on display field 2:
Digital idle speed control is only active with Closed Throttle Position (CTP) switch closed.
Knock control is active starting at an engine load greater than 40% Display group 013 and/or 014.
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Notes on display field 3:

Digital idle speed control (ISC) is only active with the Closed Throttle Position (CTP) switch closed.
Ignition timing point access to digital ISC with open CTP switch: 0.0 crankshaft. During "Basic Setting" function 04, digital ISC is blocked, display shows 0.0 crankshaft. Ignition timing point access to DLS during "Read Measuring Value Block" function 08 at idle without electrical consumers:
0.0 3.0 crankshaft.
Pa
ge 272 of 366 On Board Dia
gnostic
(OBD
) - Multi
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jection
(MFI
)
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1