AUDI A8 1997 D2 / 1.G AEB Engine Motronic MFI And Ignition System

function 06, and press -Q- button to confirm
input.

- Switch ignition off.
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Continuation

- Disconnect 4-pin connector (black) for Oxygen
Sensor (O2S) 2 -G108- behind Three Way
Catalytic Converter (TWC).

If resistance is NOT OK:
If resistance is OK: - Connect multimeter US 1119 (Fluke 83 or equivalent) between HO2S
connector terminals 1 and 2, using VW 1594 connector test kit.
- Measure resistance.

Specified value: 0.00-19.9 - Replace Heated Oxygen Sensor (HO2S) behind TWC -G108-.
- Switch multimeter to 20 VDC measuring range.
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If display = Htg.aC.ON:
If display is switching between "Htg.aC.ON" and "Htg.aC.OFF" - Connect multimeter between harness connector terminals 1 and 2 (to
ECM), using VW 1594 connector test kit.
- Measure voltage supply and check display in display group 41, display
field 4.
Specified value: 11.0-14.5 volts Specified value: 0.0-12.0 volts (oscillating)
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If there is no voltage:

If there is still no voltage: - Connect multimeter between harness connector terminal 1 (to ECM)
and vehicle Ground, using VW 1594 connector test kit.
Specified value: 11.0-14.5 volts
- Check wiring between terminal 1 and relay panel using appropriate
wiring diagram.
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If there is voltage:

If display = Htg.aC.ON:
If display switches between "Htg.aC.ON" and "Htg.aC.OFF:" - Connect multimeter between harness connector terminal 2 (to ECM)
and Battery Positive Voltage (B+), using VW 1594 connector test kit.
- Measure voltage supply and check display in display group 41, display
field 4.
Specified value: 11.0-14.5 volts Specified value: 0.0-12.0 volts (oscillating)
- Switch ignition off.
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If there is no voltage:

- Connect VAG 1598/22 test box to ECM harness
connector Page 01
-56
.

If wiring is OK: - Check wiring for open circuit between ECM/test box and 4-pin HO2S
harness connector (to ECM).

Connector terminal 2 to ECM/test box socket 28
Specified value: max. 1.5
- Replace ECM -J220- Page 01
-57
- Carry out adaptation of throttle valve control module to ECM Page
24
-119
.
- 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
.
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Oxygen Sensor (O2S) aging, checking


Required special tools and test equipment

VAG 1551 or VAG 1552 Scan Tool (ST) with
VAG 1551/3 adapter cable

Test requirements
Engine Coolant Temperature (ECT) at least
85 C (185 F)
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Function test

- 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-, -3- and -4- to input display group number 34, and
press -Q- button to confirm input.
System in Basic Setting 34 1 2 3 4

Indicated on display (1-4 = display fields)
Note:
To be sure that the temperature is within the specified range, the specified
RPM has to be maintained for at least 1 minute. Observe status of oxygen
sensor control in display field 4. - Increase engine speed to 1800-2200 RPM and compare display with
specified values for oxygen sensor aging (display fields 1-4).
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Display fields

1 2 3 4
Display group 34: Oxygen sensor aging (time period check of oxygen sensor)
Display xxxx RPM xx.xx ms xx.xx s Test OFF/Test ON
B1-S1 OK/B1-S1 n.OK
Indicates Engine speed
(in 40 RPM steps) Engine load Time period oxygen sensor Diagnostic status
Diagnostic result
Range 0-6800 RPM 0.00-8.50 ms 0.00-5.00 s ---
Specified value 1800-2200 RPM 0.8-2.0 ms 0.00-3.30 s B1-S1 OK

--- --- If not as specified Page 24
-54
, Continuation
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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
.
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yp
e=re
pair&id=AUDI.B5.FU02.24.1