sensor AUDI A4 1999 B5 / 1.G AC System Electrical Testing Workshop Manual

01-119
Electrical testing, 1996

Note:
Electrical testing, 1997 page 01
-135
.
Test
number Component(s) tested:
Page
1
- A/C control head -E87- voltage supply, ground connection and illumination. Page 01
-
120

2
- Temperature sensors G17, G56 and G89 Page 01
-
122

3
- Fresh Air Blower V2 and Control module for fresh air blower J126 Page 01
-
124

4
- Air/temperature distribution flap motors and related potentiometers V68/-G92-, -V70-/G112,
V71/G113 and V85/G114) Page 01
-
126

5
- A/C compressor speed sender G111
- Refrigerant pressure switches -F118- and -F73-
- Interior Temperature Sensor Fan V42
- "A/C compressor intervention" output
- "Excessive engine temperature" signal Page 01
-
128

6
- A/C Clutch Relay J44
- Actuation for coolant fan stage 1 Page 01
-
133

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01-122
Test No. 2 (temperature sensors G17, G56 and G89) VAG1598/11 adapter cable Measuring range: Resistance measurement (20 kohm)
Test
step VAG1598
socket Test of
Test conditions
- additional steps Specified values
Corrective action
2.1 48 + 52 Outside Air
Temperature
Sensor G17
Measure
temperature at
mounting location
of sensor - resistance table, page 01
-
123
(Resistance values
depend on measured
temperatures at mounting
location of sensor(s)
- Determine and rectify
short circuit, open circuit
in wiring or contact
resistance using wiring
diagram.
- Replace applicable
temperature sensor
page 87
-106

2.2 50 + 52 Instrument Panel
Interior
Temperature
Sensor G56
Measure
temperature at
mounting location
of sensor
2.3 47 + 52 Fresh Air Intake
Duct Temperature
Sensor G89 Measure
temperature at
mounting location
of sensor
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01-123
Temperature sensor resistances (based on ambient temperature, resistance in k ohm) Temperature measured at mounting
location of sensor Instrument Panel
Interior
Temperature
Sensor
-G56- Outside Air Temperature Sensor -G17- and Fresh Air
Intake Duct Temperature Sensor -G89-
-40 C (-40 F)
(100) (34.7)
-30 C (-22 F) (52.7) 18.1
-20 C (1 F) (28.6) 9.95
-10 C (14 F) 16.2 5.59
0 C (32 F) 9.40 3.28
5 C (41 F) 7.27 2.54
10 C (50 F) 5.66 1.99
15 C (59 F) 4.45 1.57
20 C (68 F) 3.50 1.25
25 C (77 F) 2.79 1.00
30 C (86 F) 2.23 0.80
35 C (95 F) 1.80 0.65
40 C (104 F) 1.45 0.53
50 C (122 F) 0.79 0.36
60 C (140 F) 0.67 0.25
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01-128
Test No. 5 (A/C Compressor Speed Sensor -G111-, refrigerant pressure switches -F118-, -F73- and Interior
Temperature Sensor Fan -V42-)
Note:
Electrical test steps 5.1 to 5.4 do not apply to vehicles equipped with Nippondenso compressors (A/C compressor speed
sensor G111 is not installed on Nippondenso compressors). VAG1598/11 adapter cable Measuring range: Resistance measurement (20 kilo ohm)
Test
step VAG1598
socket Test of
Test
conditions
- additional
steps Specified
values Corrective action
5.1 5 + 49 A/C Compressor
Speed Sender -G111-
- 0.8 kW to
1.5 kW - Determine and rectify open circuit in
wiring, contact resistance or short circuit
using wiring diagram.
- Replace -G111- page 87
-63
.
5.2 5 and
ground A/C Compressor
Speed Sender -G111-
- greater
than
2 kW - Determine and rectify short circuit using
wiring diagram.
- Replace -G111- page 87
-63
.
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01-131

VAG1598/11 adapter cable Measuring range: Voltage measurement (20 V)
Test
step VAG1598
socket Test of
Test
conditions
- additional
steps Specified
values Corrective action
5.6 3 + ground A/C Refrigerant Low
Pressure Switch -F73-
Ignition on- approx.
battery voltage - Determine and rectify open circuit in
voltage supply using wiring diagram.
- -F73- malfunction page 87
-66
- Refrigerant circuit empty, refrigerant
system pressure test page 87
-190

VAG1598/11 adapter cable Measuring range: Amperage (20 amps (A))
Test
step VAG1598
socket Test of
Test
conditions
- additional
steps Specified
values Corrective action
5.7 44 +
ground Interior
Temperature
Sensor Fan -V42-
Ignition
on - less than
1 A
- Blower
V42 runs - Determine and rectify open circuit, short circuit to
positive/ground in the wiring/connections between
V42 and -E87- using wiring diagram.
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01-135
Electrical testing, 1997

Note:
Electrical testing, 1996 page 01
-119
.
Notes:

VAG1598 test box must not be connected to A/C control head -E87- when performing On Board Diagnostic with VAG1551
Scan Tool (ST)
Further notes, test requirements, connecting adapter cables and test equipment page 01
-115
.
From m.y. 1997, do not connect VAG1598 test box to -E87- for test steps 1.1 through 5.7. (Test box only to be connected
for test steps 5.8, 5.9 and 5.10). Test
number Component(s) tested:
Page
1
- A/C control head -E87-, voltage supply and ground connection
- Signal for time span ignition off Page 01
-
136

2
- Temperature sensors -G17-, G56, -G89- -G191- and -G192- Page 01
-
138

3
- Fresh air blower -V2-, Control module for fresh air blower -J126- Page 01
-
140

4
- Air/temperature distribution flap motors and related potentiometers (-V68-/-G92-, -V70-/-
G112-, -V71-/-G113-, -V85-/-G114-) Page 01
-
141

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5
- A/C pressure switch -F129-
- "A/C compressor intervention" output
- "Excessive engine temperature" signal
- Interior temperature sensor fan -V42- Page 01
-
142

6
- A/C clutch relay -J44-, A/C clutch -N25-, actuation
- Coolant fan -V7-, actuation Page 01
-
146

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01-138
Test No. 2 (Temperature Sensors -G17-, -G56-, -G89-, G191-, G192-. ) Adapter cable VAG1598/11
Measuring range: Resistance measurement (20 K / 200 K ) Test
Step VAG1598
socket Test of
Test conditions
- additional work Specified Value
Corrective action
2.1 to
2.3 page 01
-122

2.4 26 + 49 Sender for outlet
temperature,
center -G191-. - Measure
temperature at
mounting location
of sensor. - Dependant on temperature
at mounting location of
sensor - Diagnose and repair short,
open circuit or contact
resistance in
wiring/connections using
wiring diagram.
2.5 25 + 49 Sender for outlet
temperature, floor
outlet -G192-. - Measure
temperature at
mounting location
of sensor. Confirm using
temperature/resistance
table page 01
-139

- Replace sensor(s)
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01-139
Temperature sensor resistances (based on ambient temperature, resistance in k ohm)
Temperature measured at mounting
location of sensor Sender for outlet temperature,
center -G191- Sender for outlet temperature, floor
outlet -G192-
-30 C (-22 F)
(141) (52,7)
-20 C (1 F) (85) (28,6)
-10 C (14 F) (47) 16,2
0C (32F) (29) 9,40
5C (41F) (23,2) 7,27
10 C (50 F) 18,6 5.66
15 C (59 F) 15 4,45
20 C (68 F) 12,2 3,50
25 C (77 F) 10 2,79
30 C (86 F) 8,2 2,23
35 C (95 F) 6,8 1,80
40 C (104 F) 5,7 1,45
50 C (122 F) 4,0 0,97
60 C (140 F) 2,9 0,67
70 C (158 F) 2,1 0,47
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01-142
Test No. 5 (A/C pressure switch -F129-, "A/C compressor intervention" signal, engine temperature signal from
instrument cluster and Interior Temperature Sensor Fan -V42-) Adapter cable VAG1598/11
Measuring range: Resistance measurement (200 )
Test
Step VAG1598 socket
Test of
Test conditions
- additional work Specified Value
Corrective action
5.1 to
5.6 Not for 1997. A/C compressor speed sender -G111-, A/C high pressure switch -F118- and Low pressure switch -
F73- are no longer installed
Adapter cable VAG1598/11
Measuring range: Current measurement (20 A)
Test Step
VAG1598 socket
Test of
Test conditions
- additional work Specified Value
Corrective action
5.7 page 01
-131

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