2000 AUDI A4 coolant temperature

24-2


1 -
Heated Oxygen Sensor (HO2S) -G39- with
Oxygen Sensor (O2S) heater -Z19-
2 -
Engine Coolant Temperature (ECT) sensor
-G62-
4-pin connector
3 -
Harness connector for: Heated Oxygen Sensor (HO2S) -G39- and
Oxygen Sensor (O2S) heater -Z19- (4-pin,
brown) Oxygen Sensor (O2S) behind Three Way
Catalytic Converter (TWC) -G130- with
Oxygen Sensor (O2S) heater -Z29- (4-pin,
black) Engine speed (RPM) sensor -G28- (3-pin,
gray) Knock sensor (KS) 1 -G61 (3-pin, green)Knock sensor (KS) 2 -G66- (3-pin, blue)
4 -
Electronics box (E-box) with: Motronic Engine Control Module (ECM) -
J220- Barometric Pressure (BARO) sensor -F96-
Pa
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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
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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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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
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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 26 of 135 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
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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 39 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

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

Engine Coolant Temperature (ECT) at least
85 C (185 F)
Pa
ge 58 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