1998 AUDI A4 display

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.
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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
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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)
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24-54

- Compare display and specified values (display
fields 3 and 4):

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.aC.ON

--- --- If not as specified page 24
-55
, 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
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24-56


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 VW1594 connector test kit.
- Measure voltage supply and check display in display group 40, display
field 4.
Specified value: 11.0-14.5 volts Specified value: 0.0-12.0 volts (oscillating)
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24-58
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 VW1594 connector test kit.
- Measure voltage supply and check display in display group 40, 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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24-60

Oxygen Sensor (O2S) aging, bank 1,
sensor 1, checking


Required special tools and test equipment

VAG1551 or VAG1552 Scan Tool (ST) with
VAG1551/3 adapter cable

Test requirements
Engine Coolant Temperature (ECT) at least
80 C (176 F)

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

Indicated on display
- Press buttons -0-, -3- and -4- to input display group number 34 (034),
and press -Q- button to confirm input.
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