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

24-11

Idle speed, checking


Notes:

Idle speed, ignition timing and CO-content
cannot be adjusted.
Idle speed is maintained by the Throttle valve
control module.
CO-content is maintained and adjusted by
Oxygen Sensor (O2S) control. Malfunctions in
O2S control are recognized by On Board
Diagnostic (OBD) and stored in DTC memory.

Required special tools and test equipment
VAG 1551 Scan Tool (ST) with VAG 1551/3
adapter cable

Test conditions
No malfunctions stored in DTC memory
Page 01
-15


Engine Coolant Temperature (ECT) at least
85 C (185 F)

All electrical consumers switched off
Pa
ge 15 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

24-12

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 -4- to select "Basic Setting" function 04, and
press -Q- button to confirm input.
System in Basic Settin
g
HELP
Input displa
y group number XXX

Indicated on display
- Press buttons -0-, -0- and -1- to input display group number 1, and
press -Q- button to confirm input.
System in Basic Setting 1 1 2 3 4

Indicated on display (1-4 = display fields)
Note:
After selecting function 04, the ECM initiates the following:
Continue with the test only when the operating conditions in display field 4
are satisfied.
EVAP canister purge regulator valve is closedA/C compressor is switched of
f
-
Briefly raise engine speed (acceleration burst) and let engine run at idle
Pa
ge 17 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

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.
Pa
ge 19 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

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.
Pa
ge 21 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

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
ge 23 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

24-17

Heated Oxygen Sensor (HO2S) and
oxygen sensor control (before TWC),
checking


Notes:

Connector for Heated Oxygen Sensor (HO2S)
before Three Way Catalytic Converter (TWC):
4-pin, brown
Component location Page 24
-1

Required special tools and test equipment

VAG 1551 or VAG 1552 Scan Tool (ST) with
VAG 1551/3 adapter cable
VAG 1598/22 test box
Multimeter US 1119 (Fluke 83 or equivalent)
VW 1594 connector test kit
Wiring diagram

Test conditions

Pa
ge 25 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

24-21

Continuation
If the value in display field 1 is NOT OK, or if the
value does not fluctuate by at least 2 %:

- Road test to condition oxygen sensor (eliminate
possible contamination) and repeat test.
If the value in display field 1 is still NOT OK, or if
it still does not fluctuate by at least 2 %:

- Check Oxygen Sensor (O2S) heater Page 24
-
27
.
If the value in display field 1 remains constant:

- Check oxygen sensor voltage (display field 2).

-
Press button to advance program
sequence.
- Press buttons -0- and -6- to select "End Output"
function 06, and press -Q- button to confirm
input.

- Switch ignition off.
Pa
ge 31 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

24-38

Continuation
If displayed values are NOT OK (not as
specified):

- Road test to condition oxygen sensor (eliminate
possible contamination) and repeat test.
If the values in display fields 1 and 2 are still
NOT OK:

- Check Oxygen Sensor (O2S) heater Page 24
-
43
.

- Briefly accelerate engine over 3000 RPM.
If the value in display field 1 remains constant:
page Page 24
-39
, Evaluation of display group
36.
Pa
ge 52 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

24-54

Continuation
If displayed value is NOT OK (not as specified):

- Road test to condition oxygen sensor (eliminate
possible contamination) and repeat test.
If displayed value is still NOT OK:

- Replace HO2S -G39-.

- Check readiness code Page 01
-59
. If
Diagnostic Trouble Code (DTC) memory has
been erased, or ECM was disconnected,
generate new readiness code Page 01
-62
.
Pa
ge 70 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

24-55

Engine operating conditions (engine
electronics), checking


Note:
This test checks whether the Motronic Engine
Control Module (ECM) -J220- recognizes the
engine operating conditions.

Required special tools and test equipment

VAG 1551 or VAG 1552 scan tool with VAG
1551/3 adapter

Test requirements
Engine oil temperature at least 80 C (176
F)

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.
Pa
ge 71 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