1997 AUDI A4 AHA Engine Multiport Fuel Injection And Ignition System Workshop Manual

24-37

Continuation

- Disconnect 4-pin connector (black) for
respective Heated Oxygen Sensor (HO2S).

If resistance is NOT OK: - Connect multimeter US1119 (Fluke 83 or equivalent) between HO2S
connector terminals 1 and 2, using VW1594 connector test kit.
- Measure resistance.

Specified value: 0.0-19.9 - Replace respective Heated Oxygen Sensor (HO2S).
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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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24-39
If there is no voltage:

If there is still no voltage: - Connect multimeter between harness connector terminal 1 (to ECM)
and vehicle Ground, using VW1594 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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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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24-41
If there is no voltage:

- Connect VAG1598/22 test box to ECM harness
connector page 01
-67
.

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 27
Specified value: max. 1.5
- Replace Motronic ECM -J220- page 01
-68
- Initiate adaptation of throttle valve control module to ECM page 24
-
150
.
- Check readiness code page 01
-70
. If Diagnostic Trouble Code
(DTC) memory has been erased, or ECM was disconnected, generate
new readiness code page 01
-73
.
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24-42

Oxygen Sensor (O2S) and Oxygen
Sensor (O2S) control behind TWC,
checking


Notes:

Connector for Oxygen Sensor (O2S) behind
Three Way Catalytic Converter (TWC) -G130-
(bank 1, sensor 2): 4-pin, green
Connector for Oxygen Sensor (O2S) 2 behind
Three Way Catalytic Converter (TWC) -G131-
(bank 2, sensor 2): 4-pin, brown
Component locations page 24
-1

Required special tools and test equipment

VAG1551 or VAG1552 Scan Tool (ST) with
VAG1551/3 adapter cable
VAG1598/22 test box
Multimeter US1119 (Fluke 83 or equivalent)
VW1594 connector test kit

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Wiring diagram

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