engine AUDI A8 1996 D2 / 1.G AEB Engine Motronic MFI And Ignition System

24-13

- Compare display with specified values (display
fields 1-4):

Display fields

1 2 3 4
Display group 1: Engine idle speed
Display xxxx RPM
xxx.x C
xx.x% xxxxxx
Indicates Idle speed Engine Coolant
Temperature (ECT) Oxygen sensor control Adjustment
conditions
Range 0-6800 RPM
(in 40 RPM steps) --- -25.0 to 25.0 % ---
Specified
value 760-960 RPM
80.0 -105.0 C
In the range from -10.0 to 10.0 %,
the value must change by at least
2 % 111111

If not as specified Page 24
-99
,
Throttle valve control module,
checking
--- If not as specified Page 24
-99
,
Throttle valve control module,
checking
Explanation
Page 24
-15

If displayed values are OK (as specified):

- Press -C- button.

- Press buttons -0-, -5- and -6- to input display
group number 56, and press -Q- button to
confirm input.
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11/19/2002 htt
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.1

24-14

- Compare display with specified values (display
fields 1-4):
Display fields

1 2 3 4 Display group 56: Engine idle speed
Display xxxx RPM xxxx RPM x.xx g/s xxxx
Indicates Engine speed
(actual) Engine
speed
(specified) Mass air flow
(idle speed control) Operating
conditions
Range 0-2550 RPM
(steps of 10 RPM) --- -2.80 to 4.17 g/s ---
Specified
value 820-900 RPM 860 RPM -1.11 to 1.11 g/s 0000

If not as specified Page 24
-99
,
Throttle valve control module,
checking
--- If not as specified Page 24
-99
,
Throttle valve control module,
checking
Explanation
Page 24
-16


-
Press button to advance program
sequence.
- Press buttons -0- and -6- to select "End Output"
function 06, and press -Q- button to confirm
input.
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11/19/2002 htt
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yp
e=re
pair&id=AUDI.B5.FU02.24.1

24-15
Evaluation of 6-digit display:

"1" = Adjustment conditions fulfilled
"0" = Adjustment conditions not fulfilled
If adjustment conditions have been fulfilled (indicated in display field 4), a series of 6 numerals ("1") will be displayed. If
one of the digits in the 6-digit display is "0," the adjustment condition has not been fulfilled. Repair the cause of the
unfulfilled condition, and repeat the test.
Explanation (display = 1)
x
x
x
x
x
x
Adjusting conditions (display group 1)
1
Engine Coolant Temperature (ECT) above 80 C
1 Engine speed less than 2000 RPM
1 Throttle valve closed
1 Oxygen sensor control active
1 Closed Throttle Position (CTP) switch closed
1 A/C compressor off
Pa
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p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.1

Engine Coolant Temperature (ECT) at least
85 C (185 F)
Pa
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yp
e=re
pair&id=AUDI.B5.FU02.24.1

24-18

Checking

- Connect VAG 1551 or VAG 1552 scan tool and
press buttons -0- and -1- to insert "Engine
Electronics" address word 01 (with engine
running at idle) Page 01
-7 .
Rapid data transfer
HELP
Select function XX

Indicated on display
- Press buttons -0- and -8- to select "Read Measuring Value Block"
function 08, and press -Q- button to confirm input.
Read Measurin
g Value Block
HELP
Input displa
y group number XXX

Indicated on display
- Press buttons -0-, -3- and -2- to input display group number 32, and
press -Q- button to confirm input.
Read Measuring Value Block 32 1 2 3 4

Indicated on display (1-4 = display fields)
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24-22
Evaluation of display group 32 Display group:
32


Display fields: 1
+ 2
Possible cause
Corrective action
O2S control
learning value:
-26.0 to -8.0 %
Engine oil dilution (when partial load learning value
is normal, display field 2)
- Change engine oil, or carry out extensive road
test and check again.


Fuel pressure too high- Check fuel pressure regulator Page 24
-93


Fuel injector leaking- Check fuel injectors Page 24
-87


Oxygen Sensor (O2S) heater malfunction- Check O2S heater Page 24
-27
O2S control
learning value:
8.0-26.0 %
Intake air leaks ("false air") or exhaust manifold
leaks (when partial load learning value is normal,
display field 2)
Repair Manual, 1.8 Liter 4
-Cyl. 5V Turbo
Engine Mechanical, Engine Code(s): AEB, ATW, Repair Group 26
- Check intake air system for leaks Page 24
-
97

- Check exhaust system for leaks:


Fuel pressure too low- Check fuel pressure regulator Page 24
-93


Oxygen Sensor (O2S) heater malfunction- Check O2S heater Page 24
-27
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24-24

Checking HO2S reference voltage

- Disconnect 4-pin connector -1- (brown) for
HO2S -G39-.

If voltage is NOT OK:
If voltage is OK: - Connect multimeter US 1119 (Fluke 83 or equivalent) between harness
connector terminals 3 and 4 (to ECM), using adapter cables from VW
1594 connector test kit.
- Start engine and measure voltage.
Specified value: 0.40-0.50 volts
- Switch ignition off.
- Check HO2S wiring Page 24
-25
- Replace Heated Oxygen Sensor (HO2S) -G39-.
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.1

Engine Coolant Temperature (ECT) at least
85 C (185 F)
Pa
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(MFI
) and i
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11/19/2002 htt
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.1

24-28

Checking

- Connect VAG 1551 or VAG 1552 scan tool and
press buttons -0- and -1- to insert "Engine
Electronics" address word 01 (with engine
running at idle) Page 01
-7 .
Rapid data transfer
HELP
Select function XX

Indicated on display
- Press buttons -0- and -8- to select "Read Measuring Value Block"
function 08, and press -Q- button to confirm input.
Read Measurin
g Value Block
HELP
Input displa
y group number XXX

Indicated on display
- Press buttons -0-, -4- and -1- to input display group number 41, and
press -Q- button to confirm input.
Read Measuring Value Block 41 1 2 3 4

Indicated on display (1-4 = display fields)
Pa
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(MFI
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11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.1

Engine Coolant Temperature (ECT) at least
85 C (185 F)
Pa
ge 49 of 135 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.1