wiring AUDI A4 1998 B5 / 1.G AHA Engine Multiport Fuel Injection And Ignition System Workshop Manual

24-10

WARNING!

Be alert when working on or near the engine
and ignition wires. High secondary ignition
voltage can cause serious personal injury
and damage vehicle components.

DO NOT touch or disconnect ignition system
wires when the engine is running or being
cranked at starting RPM.
DO NOT operate the starter if fuel injectors
are removed.

Be sure the ignition is switched OFF, when:
Disconnecting or connecting the battery,
ignition wires, or test equipment leads
Disconnecting fuel injection system wiring
Washing the engine or engine
compartment.

BEFORE cranking the engine at starting RPM
(e.g. for compression testing) disable ignition
and fuel injection systems:
Disconnect connector for ignition coil power
Pa
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24-21
Evaluation of display group 1 Display
Group: 1


Display
field: 1
Possible malfunction cause
Corrective action
less than
620
(all-wheel
drive)
or
less than
740
(front-wheel
drive)
Driving mode engaged
Adaptation of throttle valve control module -J338- to
engine control module cannot be conducted
Throttle valve control module malfunction- Move selector lever into "P" or "N" position
- Carry out adaptation of throttle valve control
module -J338- to ECM page 24
-150

- Check -J338- page 24
-128
less than
740
(front-wheel
drive)
B+ (15) to terminal 10 of ECM missing- Check voltage supply to terminal 10 on ECM
per wiring diagram
greater than
740
(all-wheel
drive) Adaptation of throttle valve control module -J338- to
engine control module cannot be conducted
Closed Throttle Position (CTP) switch open
Throttle valve control module malfunction- Carry out adaptation of throttle valve control
module -J338- to ECM page 24
-150

- Check -J338- page 24
-128
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port Fuel In
jection
(MFI
) and i
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Wiring diagram

Test conditions
Engine Coolant Temperature (ECT) at least
80 C (176 F)
Pa
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port Fuel In
jection
(MFI
) and i
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pair&id=AUDI.B5.FU03.24.1

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
Pa
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port Fuel In
jection
(MFI
) and i
gnition s
ystem
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24-29

Checking HO2S reference voltage (Banks 1,
2)

- Disconnect 4-pin connector for respective
HO2S.

If voltage is NOT OK:
If voltage is OK: - Connect multimeter US1119 (Fluke 83 or equivalent) between harness
connector terminals 3 and 4 (to ECM), using adapter cables from
VW1594 connector test kit.
- Start engine and measure voltage.
Specified value: 0.40-0.50 volts
- Switch ignition off.
- Check HO2S wiring.

Bank 1, sensor 1 page 24
-30
.

Bank 2, sensor 1 page 24
-32
.
- Replace respective Heated Oxygen Sensor (HO2S).
Pa
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port Fuel In
jection
(MFI
) and i
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play?action=Goto&t
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24-30

Checking HO2S wiring, bank 1, sensor 1

- Disconnect 4-pin connector (black) for HO2S -
G39-.

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

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

Connector terminal 3 to ECM/test box socket 25
Connector terminal 4 to ECM/test box socket 26
Specified value: max. 1.5
- Check wiring for short circuits between terminals of 4-pin connector,
and between connector and ECM/test box.

Connector terminal 4 to ECM/test box socket 25
Specified value:
- Check wiring for short circuits to wiring harness shielding.

Connector terminal 4 to ECM/test box socket 14
Connector terminal 3 to ECM/test box socket 14
Specified value:
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
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pair&id=AUDI.B5.FU03.24.1

24-31
If wiring is OK:

- Replace Motronic ECM -J220- page 01
-68
.

- Carry out 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
.
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
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pair&id=AUDI.B5.FU03.24.1

24-32

Checking HO2S wiring, bank 2, sensor 1

- Disconnect 4-pin connector (black) for HO2S -
G108-.

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

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

Connector terminal 3 to ECM/test box socket 39
Connector terminal 4 to ECM/test box socket 40
Specified value: max. 1.5
- Check wiring for short circuits between terminals of 4-pin connector,
and between connector and ECM/test box.

Connector terminal 4 to ECM/test box socket 39
Specified value:
- Check wiring for short circuits to wiring harness shielding.

Connector terminal 3 to ECM/test box socket 14
Connector terminal 4 to ECM/test box socket 14
Specified value:
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
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pair&id=AUDI.B5.FU03.24.1

24-33
If wiring is OK:

- Replace Motronic ECM -J220- page 01
-68
.

- Carry out 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
.
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

24-34

Oxygen Sensor (O2S) heater before
TWC, checking


Notes:

Connector for Oxygen Sensor (O2S) heater -
Z19- (bank 1, sensor 1): 4-pin, black.
Connector for Oxygen Sensor (O2S) 2 heater -
Z28- (Bank 2, sensor 1): 4-pin, black.
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
Wiring diagram

Test requirements
Pa
ge 44 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