display AUDI A8 1999 D2 / 1.G AHA Engine Multiport Fuel Injection And Ignition System User Guide

24-28
Evaluation of display group 33 Display group:
33


Display fields:
2, 4
Possible malfunction cause
Corrective action
approx. 0.435 V

Open circuit in wiring between HO2S connector terminal
4 and ECM - Check reference voltage page 24
-29
approx. 0.435 V

Open circuit in wiring between HO2S connector terminal
3 and ECM
approx. 1.085 V
Short circuit to positive (B+) between HO2S connector
terminal 4 and ECM - Check HO2S wiring, bank 1, sensor 1
page 24
-30

- Check HO2S wiring, bank 2, sensor 1
page 24
-32

approx. 0.000 V

Short circuit to Ground between HO2S connector
terminal 4 and ECM
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24-35

Checking

- Connect VAG1551 or VAG1552 scan tool and
press buttons -0- and -1- to insert "Engine
Electronics" address word 01 (with engine
running at idle) page 01
-8 .
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 -0- to input display group number 40 (040),
and press -Q- button to confirm input.
Read Measuring Value Block 40 1 2 3 4

Indicated on display (1-4 = display fields)
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24-36

- Compare display and specified values (display
fields 1 and 2):

Display fields

1 2 3 4
Display group 40: Oxygen Sensor (O2S) heating (before and after TWC)
Display
xx.x
Htg.bC.ON/Htg.bC.OFF
xx.x
Htg.aC.ON/Htg.aC.OFF
Indicates Resistance of O2S heater
(before TWC)
(B1-S1 and B2-S1) O2S heater ON
or
O2S heater OFF
(before TWC)
(B1-S1 and B2-S1) Resistance of O2S heater
(after TWC)
(B1-S2 and B2-S2) O2S heater ON
or
O2S heater OFF
(after TWC)
(B1-S2 and B2-S2)
Range
0.0 - 65.0
--- --- ---
Specified value
2.4 - 9.2
Htg.bC.ON --- ---

If not as specified page 24
-37
, Continuation
--- ---
If displayed values are OK (as specified):

-
Press button.
-
Press buttons -0- and -6- to select "End Output"
function 06, and press -Q- button to confirm
Pa
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24-38
If resistance is OK:

- Switch multimeter to 20 VDC measuring
range.

If display = Htg.bC.ON:
If display switches between "Htg.bC.ON" and "Htg.bC.OFF:" - Connect multimeter between harness connector terminals 1 and 2 (to
ECM), using VW1594 connector test kit.
- Measure voltage supply and check display in display group 40, display
field 2.
Specified value: 11.0-14.5 volts Specified value: 0.0-12.0 volts (oscillating)
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11/23/2002 htt
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play?action=Goto&t
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24-40
If there is voltage:

If display = Htg.bC.ON:
If display switches between "Htg.bC.ON" and "Htg.bC.OFF:" - Connect multimeter between harness connector terminal 2 (to ECM)
and Battery Positive Voltage (B+), using VW1594 connector test kit.
- Measure voltage supply and check display in display group 40, display
field 2.
Specified value: 11.0-14.5 volts Specified value: 0.0-12.0 volts (oscillating)
- Switch ignition off.
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24-43

Function test

- Connect VAG1551 or VAG1552 scan tool and
press buttons -0- and -1- to insert "Engine
Electronics" address word 01 (with engine
running at idle) page 01
-8 .
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 -6- to input display group number 36 (036),
and press -Q- button to confirm input.
Read Measuring Value Block 36 1 2 3 4

Indicated on display (1-4 = display fields)
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24-44

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

Display fields

1 2 3 4
Display group 36: Oxygen Sensor (O2S) behind Three Way Catalytic Converter (TWC), Banks 1, 2
Display x.xxx V Test OFF/Test
ON
B1-S2 ok
B1-S2 n.ok x.xxx V Test OFF/Test
ON
B2-S2 ok
B2-S2 n.ok
Indicates Voltage supply to O2S behind
TWC
(Bank 1, Sensor 2) Diagnostic status
Diagnostic result Voltage supply to O2S 2 behind
TWC
(Bank 2, Sensor 2) Diagnostic status
Diagnostic result
Range 0.000 - 1.000 V --- 0.000 - 1.000 V ---
Specified
value 0.000 - 1.000 V
(can oscillate slightly) B1-S2 OK 0.000 - 1.000 V
(can oscillate slightly) B2-S2 OK

If not as specified page 24
-45
, Continuation
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24-45

Continuation

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

- Check Oxygen Sensor (O2S) heater(s) page
24
-52
.

- Briefly accelerate engine over 3000 RPM.
If the value in either display field 1 or field 3
remains constant:
page Page 24
-46
, Evaluation of display group
36.
Pa
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24-46
Evaluation of display group 36 Display group:
36


Display fields:
1, 3
Possible malfunction cause
Corrective action
approx. 0.435 V

Open circuit in wire -4- between oxygen sensor and
ECM - Check reference voltage page 24
-47
approx. 0.440 V

Open circuit in wire -3- between oxygen sensor and
ECM
approx. 1.085 V
Short circuit to B+ in wire -4- between oxygen sensor
and ECM - Check O2S wiring, bank 1, sensor 2
page 24
-48

- Check O2S wiring, bank 2, sensor 2
page 24
-50

approx. 0.000 V

Short circuit to Ground in wire -4- between oxygen
sensor and ECM
Pa
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port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1

24-53

Checking

- Connect VAG1551 or VAG1552 scan tool and
press buttons -0- and -1- to insert "Engine
Electronics" address word 01 (with engine
running at idle) page 01
-8 .
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 -0- to input display group number 40 (040),
and press -Q- button to confirm input.
Read Measuring Value Block 40 1 2 3 4

Indicated on display (1-4 = display fields)
Pa
ge 67 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1