transmission AUDI A4 2000 B5 / 1.G AC System Electrical Testing Workshop Manual

01-115


A/C system, electrical testing

Notes:

Vehicles 1997 page 01
-135
.

VAG1598 test box must not be connected to -
E87- when performing On Board Diagnostic
with VAG1551 Scan Tool (ST)

Test equipment required

Requirements
CAUTION!
Switch multimeter to the appropriate measuring range before
VAG1598 test box with adapter cables VAG1598/11, VAG1598/12
and VAG1594 adapter set Fluke 83 multimeter (US 1119) or equivalentUS 1115 LED tester ThermometerBattery Positive Voltage (B+) OK Ground (GND) connections on engine and transmission OK Fuse No. 42 (S42), 51 (S51), 225 (S225) and 15 (S15) OK
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01-143

A/C control head -E87- connected to test box with adapter cable VAG1598/11
LED Voltage tester VAG1527B
Test
Step VAG1598
socket Test of
Test conditions
- additional work Specified
Value Corrective action
5.8 14 + 12 "A/C compressor
intervention"
output.
Engine
running. A/C
compressor
off
- Switch on A/C
compressor - LED lights
up


- LED lights
up slightly
dimmer. - Diagnose and repair open or short circuit in
wiring/connections using wiring diagram.
- Diagnose and eliminate A/C compressor
cut-off condition(s) from Engine Control
Module (ECM) or Transmission Control
Module (TCM)
- Diagnose and repair short circuit to ground
in wiring/connections using wiring diagram.
5.9 Ground
and
51 "Engine
temperature too
high" signal. Engine
running. - LED lights
up. - Diagnose and repair short circuit to ground
in wiring/connections using wiring diagram.
- Diagnose and eliminate A/C compressor
cut-off condition from Instrument cluster
Pa
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ystem, electrical testin
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11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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pair&id=AUDI.B5.HA01.01.2

01-144

A/C control head -E87- connected to test box with adapter cable VAG1598/11
Measuring range: Current measurement (200 mA)
Test
Step VAG1598
socket Test of
Test conditions
- additional work Specified
Value Corrective action
5.10 Ground
and
12
"A/C compressor
intervention"
output.
Engine running. A/C compressor
off

- Switch on A/C
compressor



- Remove multimeter
connector probes
from test box - Less than 5
mA



- Less than
50 mA
- Compressor
does not en-
gage
- Compressor
engages
Repair Manual, Fuel Injection and
Ignition
Repair Manual, Automatic
Transmission - Diagnose and repair short circuit to
positive in wiring/connections using
wiring diagram.
- Replace A/C control head -E87-.



- Diagnose and eliminate A/C
compressor cut-off condition(s) from
Engine Control Module (ECM) or
Transmission Control Module (TCM)
- Diagnose and repair short circuit to
ground in wiring/connections using
wiring diagram.
Pa
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ystem, electrical testin
g
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.2