wiring AUDI A4 2000 B5 / 1.G AHA Engine Multiport Fuel Injection And Ignition System Owner's Manual

24-57
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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24-59
If specified value is not attained:

- 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 O2S
harness connector (to ECM).

Connector terminal 2 to ECM/test box socket 28
Specified value: max. 1.5
- Replace 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
.
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24-68

Mass Air Flow (MAF) sensor, checking


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
All electrical consumers switched off (coolant
fan must not run during test).
A/C must be switched off
Fuse for MAF sensor OK
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24-72
Evaluation of display group 2, display field 4 Display
group: 2


Display field:
4
Possible malfunction cause
Corrective action
less than 2.8
g/s
Large amount of false air between intake air duct and
Mass Air Flow (MAF) sensor - Check intake air system for leaks (false
air) page 24
-126

larger than 5.6
g/s
Shift lever in drive range (auto. transmission)
Engine affected by additional consumers- Move shift lever into P or N
- Eliminate load (A/C, power steering,
generator)

Open circuits in wire 1 or 2 between MAF sensor and
ECM - Check voltage supply page 24
-73


Open circuit in wire 3 between MAF sensor and relay
panel - Check wiring page 24
-73
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Checking voltage supply

If there is no voltage:
Checking wiring - Disconnect 3-pin harness connector from Mass Air Flow sensor (MAF).
- Connect multimeter US1119 (Fluke 83 or equivalent) between harness
connector terminals 2 (Ground) and 3 (B+), using adapter cables from
VW1594 connector test kit.
Specified value: 9.0-14.5 volts
- Switch ignition off.
- Check wiring using applicable wiring diagram.
- Switch ignition off.
- Connect VAG1598/22 test box to ECM harness connector page 01
-
67
.
- Check wiring for open circuits, between ECM/test box and 3-pin MAF
sensor harness connector.

Connector terminal 1 to ECM/test box socket 13
Connector terminal 2 to ECM/test box socket 12
Specified value: max. 1.5
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24-74

- Check wiring for short circuits between terminals
of 3-pin connector, and between connector and
ECM/test box.


Connector terminal 1 to ECM/test box
socket 12

Specified value:

- Switch multimeter to 20 VDC measuring
range.

- Check wiring at 3-pin connector for short circuit
to B+ (battery positive voltage), according to
applicable wiring diagram.


Connector terminal 1 to vehicle Ground

Connector terminal 2 to vehicle Ground

Specified value: 0 volts
If wiring is OK:

- Replace Mass Air Flow sensor (MAF) -G70-.

-
Check readiness code page 01
-70
. If
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24-75

Engine Coolant Temperature (ECT)
sensor, checking


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
Engine cold
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24-77

- Compare display with specified value for engine
coolant temperature sensor (display field 3):

Display fields

1 2 3 4
Display group 4: General engine data
Display xxx RPM xx.xxx V
xxx.x C
xxx.x C
Indicates Engine
speed
(in 40 RPM
steps) Battery Positive
Voltage (B+) Engine coolant temperature Intake air
temperature
Range 0 - 6800
RPM 0.000 - 16.500 V -46.5 to 141.0 -46.5 to 141.0
Specified
value 0 RPM 10.000 - 14.500 V approx. ambient temperature 1), 2) ---

--- --- If specified value is not attained page 24
-79
,
Evaluation of display group 4
---
1) After a long standing period (approx. 12 hours). 2) If indicated temperature deviates significantly from the ambient temperature, check ECT sensor wiring for resistance or
open circuits.
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24-79
Evaluation of display group 4 Display group: 4


Display field: 3
Possible malfunction cause
Corrective action
approx. -46.5 C
Open circuit or short circuit in wiring to B+ - Check wiring page 24
-79
approx. 141.0 C
Short circuit to Ground

Checking wiring

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

- Disconnect 4-pin connector from ECT sensor -
G62-.

- Check wiring resistance for open circuit between ECM/test box and 4-pin
ECT sensor connector.

Connector terminal 1 to ECM/test box socket 53
Connector terminal 3 to ECM/test box socket 67
Specified value: max. 1.5
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24-80


- Check wiring for short circuit between ECM/test box and 4-pin harness
connector according to wiring diagram.

Connector terminal 1 to vehicle Ground
Connector terminal 1 to ECM/test box socket 67
Connector terminal 1 to terminal 3
Connector terminal 3 to vehicle Ground
Specified value:
- Check wiring between ECM and 4-pin harness connector for short
circuit to battery B+.

Connector terminal 1 to vehicle Ground
Connector terminal 3 to vehicle Ground
Specified value: 0 volts
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port Fuel In
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) and i
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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