Audi 90 1993 Series Quick start guide

Service
Electrical Wiring Diagrams
90
USA/Canada
m.y. 1993 ·
Technical Service Communications •

This publication contains electrical wiring diagrams for the Audi 90,
model year 1993, sold in the USA and Canada. Whenever working on
Audivehicles,followtheproceduresdescribedontheappropriateRepair
Manual Microfiche. Use of tools or procedures other than those
recommended maybe detrimental
to thesafe operation ofthe vehicleas
well as the safety of the person doing the repair.
Before working on any car, read Warnings and Cautions.
©Audi of America, Inc.
Technical Service Communications
Printed 9/94
W42 WD BOOK AU 04
All rights reserved. All information contained in this manual is based
on the latestproduct information available atthe time of printing. The
rightis reserved to make changes at anytime withoutnotice. No part
ofthispublication maybe reproduced, stored in a retrieval system, or
transmitted in any form or by any means, electronic, mechanical,
photocopying, recording or otherwise, without the prior written
permission of the publisher. This includes text, figures and tables.

General
90-AII Models
{Up to VIN: 8 CPA 000100)
USA/Canada
Cautions and warnings ..........................................·...i
How to read wiring diagrams.................................. iii
Standard circuit/terminal designations ..................vi
Standard wire/connector designations ..................vii
Symbols used in wiring diagrams........................ .. • iv
Test equipment ...•.............................................. ~ ... viii
Troubleshooting procedure................•..... .. ......... •. xv i
Wiring harness repairs .................................
.. ....•...xv
ABS combi relay (2-wheel dr ive system)............. 43
ABS Control Module (2-wheel drive system) ...... 41
ABS Quattro (with rear differential lock) .............. 63
Airbag triggering unit............................................. 55
AM / FM stereo radio (anti-theft) with 6-speakers. 69
Ashtray lights ......................................................... 49
Auto check system ................................................ 25
Automatic climate control.................... .. .......... .... .. 73
Automatic transmission and cruise control
(2-wheel drive)..................................................... 85
Auxiliary/relay panel, rear............ .. ...... .... ............... 7
Auxiliary relay panel with connector station.......... 6
Back-up light switch .............................................. 40
Brake light switch ..................... .. ........................... 40
Central locking system .......................................... 45
Cigarette lighters ..........................
.... . .. ........ ... .... ... 48
Connections and plugs on fuse/relay panel, rear . 9
Connector identification
on connector station ....... 8
Cruise control, Control Module................
... .......... 44
Daytime running lights (Canada only) ................. 97
Digital clock............................................................ 27
Dual horns...................... .. ...................................... 39
ECM (Engine Control Module).............................. 19
8-Way power front driver's seat
(w /o memory) ... 60
Emergency flasher relay ....................................... 37
Emergency switch .............................
... ................. 37
Engine compartment light ..................................... 35
Engine oil pressure sensor ................................... 57
Engine oil temperature sensor ............................. 57
Fuse panel
.... .. .. ........ .. ..... ...................................... 34
Fuse/relay panel ...................................................... 1
Generator (GEN) ...........
.. ...... .. .............................. 17
Glove compartment light ..... .................................. 35
Heated door locks ........................................
.. .. ... 105
Heated front seats .............................. .. ............. .. 107
Ignition/starter switch ............................................ 31
Instrument cluster........ .... ............................ .. ........ 29
Interior lights .......................................................... 50
Lamp Control Module, front .................................. 32
Lamp Control Module, rear ................................... 33
Main wiring diagram index
.. ... .. ............. .. .............. 10
Manual air conditioning ....................................... 1
09
Mini-check system ........... .. .............................. ... . 118
Mirror adjustment switch ............
.. ......................... 54
Index

Index
90-AII Models
(Up to VIN: 8 CPA 000100)
USA/Canada
(Continued)
90-AII Models
(From VIN: 8 CPA 000100)
USA/Canada
Power window Control Module ............................. 51
Power windows...................................................... 53
Reading lights .....
.. .............................. .. ................. 50
Seat belt warning Control Module........................ 36
Servotronic Control Module .................................. 56
Starter .... ................................................................. 17
Tilt and slide power sunroof .. ... .......................... 128
Windshield wiper intermittent switch... .. ... .. ... .... . .. 38
ABS Control Module ... .. ....................................... 157
ABS Quattro ...... .... ................................. ... ........... 165
Airbag Control Module ............
.. ........................ .. 153
AM/FM stereo radio with 6-speakers .......
... ....... 171
Auto check system .............................................. 142
Automatic climate control
(Automatic transmission) .. .... .......................... .. 176
Automatic climate control
(Manual transmission) ....................................
.. 183
Automatic transmission ................
.. ....... .. ............ 189
Auxiliary/relay panel, rear................................. .. 132
Auxiliary relay panel with connector station ...... 132
Battery .
.. .... .................................. ... ...................... 134
Central locking system .. .............. .. ...................... 151
Cruise control, Control Module ........................... 158
Daytime running lights (Canada only) ....
.. ......... 195
ECM (Engi ne Control Module) .. .... ...................... 135
8-Way power front driver's seat (w/o
memory). 162
Engine compartment light ....
.. ............................. 146
Emergency flasher relay
.. .................. .... .. ........... 147
Emergency flasher switch
.. .......................... .... ... 147
Engine oil pressure sensor
.. ............. .. ................ 160
Engine oil temperature sensor ........................... 160
Fog lights................................................ .. ............ 149
Fuel pump .................... .. ... .. ............................... .. 138
Fuse/relay panel ......................... .... .................. .. . 131
Generator.......... .... ............................. ... ............... 134
Glove compartment light ................................... .. 146
Ground connectors .............
.. ............................... 133
Heated door locks
.. ......... .. .................................. 202
Heated front seats .... ........................................... 205
Ignition/starter switch ............ ... ..... .. ............ ........ 139
Instrument cluster .... ....................................... ... .. 140
Interior lights ........................................................ 150
Lamp Control Module, front . .... ........................... 144
Lamp Control Module, rear ................................. 143
Light switch .......................................................... 145

90-AII Models
(From VIN: 8 CPA 000100)
USA/Canada
(Continued)
Manual air conditioning
(Manual transmissi on ) . ... .................................. 210
Mini-check system ......................................... .. .... 215
Mirror adjustment switch ..................................... 154
Power sunroof............................................
.. ........ 220
Power windows ............................................. .. ..... 156
Power windows Control Module .................
.. . ... .. 155
Radio
.. .............................................. .... ... ...... ... .... 159
Reading lights .. ........ .. ............... .. . .. ............... .. ..... 150
Servotronic Control Module .......................... .. .... 157
Starter......... .. ................................... .. ................... 134
Windshield wiper intermittent switch.................. 148
Index

Please read these WARNINGS and CAUTIONS before
proceeding with maintenance and repair work.
• If you lack the skills, tools and equipment, or a
suitable workshop for any procedure described in
this manual,we suggestyou leavesuch repairs toan
authorized Audi dealer or other qualified shop. We
especially urge you to consult an authorized Audi
dealer before beginning repairs on any car that may
still be covered wholly or in part by any of the
extensive warranties issued by Audi.
• Audi is constantly improving its cars and some-
times these changes, both in parts and specifica-
tions, are made applicable to earliermodels. There-
fore, part numbers listed in this manual are for
reference only. Always check with your authorized
Audi dealer parts departmentfor the latest informa-
tion.
• Never work under a lifted car unless it is solidly
supported on stands designed for this purpose. Do
not support a car on cinder blocks, hollow tiles or
other props that may crumble under continuous
load. Neverwork undera carthat is supportedsolely
by ajack. Neverwork underthe carwhile the engine
is running.
• Ifyou aregoing to workunderacar on the ground,
make sure thatthe ground is level. Block the wheels
to keep the car from rolling. Disconnect the battery
Ground (GND) strap to prevent others from starting
the car while you are under it.
• Neverrun the engine unless the work area is well
ventilated. Carbon monoxide kills.
• Tie long hair behind your head. Do not wear a
necktie, a scarf, loose clothing, ora necklace when
you work near machine tools or running engines. If
your hair, clothing, or jewelry were to get caught in
the machinery, severe injury could result.
• Illuminate the work area adequately but safely.
Use a portable safety light for working inside or
underthe car. Make sure the bulb is enclosed by a
wire cage. The hot filament of an accidentally
broken bulb can ignite spilled fuel or oil.
• Finger rings should be removed so that they
cannotcause electrical shorts, getcaught in running
machinery, or be crushed by heavy parts.
• Disconnectthe batteryGround (G NO) strapwhen-
ever you work
on the fuel system or the electrical
system. Do notsmoke orwork nearheaters orother
fire hazards. Keep an approved fi
re extinguisher
handy.
• Anytime the battery has been disconnected itwill
be necessary to reestablish Basic Settings for the
Engine Control Module (ECM) and, on vehicles with
automatic transmissions, the Transmission Control
Module (TCM), using the VAG 1551 Scan Tool (ST).
• On cars equipped with anti-theft radios, make
sure you know the correct radio activation code
before disconnecting the battery or removing the
radio. If the wrong code is entered into the radio
when power is restored, that radio may lock up and
be rendered inoperable, even if the correct code is
then entered.
• Do not attempt to work on your vehicle if you do
not feel well. You increase the danger of injury to
yourself and others if you are tired, upset or have
taken medicine or any other substance that may
impair you from being fully alert.
• Always observe good workshop practices. Wear
goggles when you operate machine tools or work
with battery acid. Glovesorotherprotectiveclothing
should be worn whenever the job requires working
with harmful substances.
• Do not re-use any fasteners that are worn or
deformed in normal use. Many fasteners are de-
signed to be used only once and become unreliable
and may fail when used a second time. This in-
cludes, but is not limited to, nuts, bolts, washers,
self-locking nuts or bolts, circlips, cotter pins. Al-
ways follow recommendations given in this publica-
tion. Always replace these fasteners with newparts.
• Friction materials such as brake pads and clutch
discs may contain asbestos fibers. Do not create
dust by grinding, sanding, or by cleaning with com-
pressed air. Avoid breathing asbestos fibers and
asbestos dust. Breathing asbestos can cause seri-
ousdiseasessuch as asbestosis orcancer, and may
result in death.
IGeneral Information I Warnings/Cautions

Please read these WARNINGS and CAUTIONS before
proceeding with maintenance and repair work.
• Catch draining fuel, oil or brake fluid in suitable
containers. Do not use empty food or beverage
containers that mightmislead someone into drinking
from them. Store flammable fluids away from fire
hazards. Wipe up spills atonce, but do not store the
oily rags, which can ignite and burn spontaneously.
• Keep sparks, lighted matches, and open flame
away from the top of the battery. Ifescaping hydro-
gen gasis ignited, itwill ignitegas trapped inthe cells
and cause the battery to explode.
• The air-conditioning (A/C) system is filled with a
chemical refrigerant that is hazardous. The AIC
system should be serviced only by trained techni-
cians using approved refrigerant recovery/recycling
equipment, trained in related safety precautions,
andfamiliarwith regulations governingthe discharg-
ing and disposal of automotive chemical refriger-
ants.
• Do not expose any part of the A/C system to high
temperatures such as open flame. Excessive heat
will increase system pressure and may cause the
system to burst.
• Some of the vehicles covered by this manual are
equippedwith asupplementalrestraintsystem (SRS),
that automatically deploys
an airbag in the event of
a frontal impact. The airbag is operated by an
explosive device. Handled improperly or without
adequate safeguards, it can beaccidently activated
andcause serious personal injury. To guard against
personal injuryorairbag system failure, only trained
Audi Service technicians should test, disassemble
or service the airbag system.
• Never use a test light to conduct electrical tests
on the airbag system. The system must only be
tested by trained Audi Service technicians using the
Audi VAG
1551 Scan Tool (ST) or an approved
equivalent. The airbag unit must never be electri-
cally tested while it is not installed in the vehicle.
ii Wa rnings/Cautions IGeneral Information I
• Before starting a job, make certain that you have
all the necessary tools and parts on hand. Read all
the instructions thoroughly, do not attempt short-
cuts. Use tools approp
ri ate to the work and use only
replacement parts meeting Audi specifications.
Makeshift tools, parts and procedures will not make
good repairs.
• Use pneumatic and electric tools only to loosen
threaded parts and fasteners, especially on light
alloy parts. Always use a torque wrench to tighten
fasteners
to the tightening torque listed.
• Be mindful of the environment and ecology. Be-
fore you drain thecrankcase, find outthe properway
to dispose of the oil. Do not pour
oi lontothe ground,
down a drain, or into a stream,pond orlake. Consult
local ordinances that govern the disposal ofwastes.
• Before doing any electrical welding on vehicles
equipped with ABS, disconnect the battery Ground
(GND) strapand the ABS Control Moduleconnector.
• When boostcharging the battery,firstremove the
fuses for the Engine Control Module (ECM), Trans-
mission Control Module (TCM), ABS Control Mod-
ule, and the On-Board computer. In cases where
one or more of these components is not separately
fused, disconnect the Control Module connector(s).
• Do not quick-charge the battery (for boost start-
ing) for longer than one minute, and do not exceed
16.5 Volts at the battery with the boosting cables
attached. Wait at least one minute before boosting
the battery a second time.
• Some aerosol tire inflators are highly flammable.
Be extremelycautiouswhen repairing atirethatmay
have been inflated usi
ng an aerosol tire inflator.
Keep sparks, open flame orothersources ofignition
awayfrom the tire repairarea. Inflateanddeflate the
tire atleastfour times before breaking the bead from
the rim. Completely remove the tire from the rim
before attempting any repair.

Fuse/Relay
panel
internal circuits
(see Standard
CircuiVferminal
~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~lgnations)
1
. ~~
.. J!Sm5coo I ~
Fuse/Relay
panel
---·-t:;~ FAN~
1.....-0,_ ____ -+___. sPEHAeLAv m/~~n~:~e:age
~-~--~~~~~~~~~------~k
Relay
(mounted on main
fuse/relay panel)
Relay location
(Example:
position #2)
Welded connection
in wiring harness
(see Positive
(+)connections
in each
Circuit Section)
Internal connections
(not actual wires)
designation
E87La
Tr
2.5 0.5
RIBL R/G
Component~
COOLANT Mi----.it<--1
Component symbol FAN
(see Symbols Used
in Wiring Diagrams)
Wire size 1
3
and color ------
(see Wiring Color --------2.5
Code and BR
Wire Size)
D75a
1.0
BUR
0.5
BUR
2.5
RIG
2.5
RIG
l
Fuse
designation
(position #20
30 amp rating)
L---+-----Fuse/Relay panel
3/7sa
2130
terminal designation
n====::z::;;:;;;:::l:::::::::::::::zi=rJ· COOLANT FAN (Example:
~b'J~~~~ODULE conn_ector D
L.!:z;&&:;:z:::::::SS::;&::::::::::;::ll mJ termlnal75a)
5fT ---- Relay location
COOLANT FAN
AFTER-RUN
RESISTOR
2.5
R/W
2.5
RIBL
l
0.5
BR
0.5
BRIG
fr-
6.0
BR
on auxiliary
relay panel
(Example:
position #18)
Terminal
designation
(Example:
panel socket
#6
terminal #31
on component)
Wire connector
(Example:
connector T3a
terminal #3)
Ground (GND) path
(Example: from
welded harness
Current track
number
lo,-------...,F-------_....,-------~------41~e---tl~--connection 82
206 208 209
Ground (GND) connection
(see Ground (GND) Connections
in each Circuit Section)
212 213
Current track reference
(Example: wire continues
at current track #238)
216 to chassis ground
connection 32)
Component ground (GND)
(through housing
mounted to ground [GND])
IGeneral Information IHow to read wiring diagrams iii

-
-
Fuse
Thermo-fuse
(Circuit Breaker
Battery
Starter
Generator (GEN)
Ignition coil
Distributor
(Mechanical)
Distributor
(Electronic)
Spark plug connector
and plug
Glow plug
Heater element
Automatic
choke
Engine Coolant
Temperature switch (ECT)
S.j_
T
iv Symbols used in wiring diagrams IGeneral Information I
Warm-up regulator
Auxiliary air valve
Solenoid valve
Motor
Wiper motor,
2-speed
Switch
(Manually operated)
Switch
(Thermally operated)
Push button switch
(Manually operated)
Switch
(Mechanically operated)
Switch
(Pressure operated)
Multiple switch
(Manually operated)
Variable resistor
(Rheostat)
Resistor,
temperature dependent
Relay
Relay
(Electronically controlled)
!97-24291

*
~
~
cp
~
117\ lfllllll ~
~~nono1
Resistance
Diode
Zener diode
LED
Instrument
(Gauge)
Electronic
Control Module
Analog clock
Digital clock
Multi-function
indicator
Buzzer
Consumption
indicator
Speed sensor
Light bulb
Light bulb
(dual-filament)
Interior light
Cigarette lighter
Rear window defogger
heat element
Horn
Push-on connector
Multi-point connector
on component
Wiring junction
Wiring connection
detachable '
Wiring connection
fixed '
Internal connection
in a component
Resistance wire
Control motor,
headlight range adjustment
Crankshaft Positi on (CKP)
sensor
Slip contact
197-24291
I General Information I Symbols used in wiring diagrams v

Standard Circuit/terminal Designations
Circuit Number Circuit Description Most Common
Wire Color
15 Powered when ignition switch is Black (BK)
in "On"
or "Start" positions
X Load-reduction circuit Black/Yellow (BKIY)
Powered by load-reduction relay when
ignition switch in
in "On" position
(Not powered
in "Start" position)
30 Battery positive(+) Voltage Red (R)
Powered whenever battery
is connected
31
Ground (GND) or battery negative(-) Brown (BR)
50
Powered only when ignition Red/Black (RISK)
switch is in "Start" position
8+
From generator (GEN) Red (R)
Charging Voltage to battery
D+ Generator (GEN) warning lightand
field energizing circuit
85 Ground (GND)
(-) side of switching relay Brown (BR)
86 Power-input(+) side
of switching relay
87 Relay change-over contact
vi How to read wiring diagrams I General Information l

Wire Color-Code
BK
BL
BR
CL
G
GY
LT.G
OR
R
v
w
y
Black
Blue
Brown
Clear
Green
Gray
Light Green
Orange
Red
Violet
White
Yellow
Combined codes indicate a multi-colored wire.
Example: The code R/G indicates a red wire with a green
tracer stripe.
Note
Sometimes the wire coloron the car maybe different than
the oneonthe wiringdiagram. Don'tbeconcerned, just be
sure to confirm that the wires connect to the proper
terminals.
Wire Size
The wiring diagrams in this manual identify wires by their
metric wire size. Metric wire sizes indicate cross-sectional
area in square millimeters (mm2
). The table below lists metric
wire sizes and their equivalents in American Wire Gauge
(AWG) sizes.
Metric size
(Cross-sectional
area-mm2)
0.35
0.5
0.75
1.0
1.5
2.5
4.0
6.0
16.0
25.0
35.0
American
Wire Gauge
(AWG)
22
20
18
16
14
12
10
8
4
2
2
Connectors
T1 .......................................... .. .................................Single-point
T2 ........
.... .... ..................................................................... 2-point
T3 ......................................
... ......... .. ......... .. .................... .. 3-point
T4..................................................................................... 4-point
T6 ..................................................................................... 6-point
T8 ..................................................................................... 8-point
T1 o .............. ...... ........ . ..................... .. ............................. 10-point
T12 ............................
.. ................................................... 12-point
T26 ................................................................................. 26-point
Each connector has a unique number. Example: T6, T6a and
T6b are three different 6-point connectors.
Wiring diagrams usually also identify a particularconnector
terminal. Example: T3a/2 is terminal two of connector T3a.
T3a
1 2 3
(T3a/2) I96-902 I
IGeneral Information I How to read wiring diagrams vii

2. Test Equipment
Special Tools
The most basic electrical troubleshooting calls for specialized
electrical test equipment. Dealer Service Department techni-
cians do this work using Special Tools, many of which are
designed specifically for working on electrical systems.
Proper tools are essential to ensure accurate test results and
to prevent damage to sensitive components.
The Special Tools shown in this manual are identified by the
order numbers that can be used to special-order the tools
through your authorized dealer Parts Department.
viii Test equipment IGeneral Information I
2.1 LED Test Light
A test light is an inexpensive tool used to perform many
simple electrical tests that would otherwise require a multime-
ter. It lights to indicate when there is Voltage potential
between any two test-points in a circuit.
With one probe contacting the battery
negative(-) terminal or
a known ground (GND) connection, the other probe can be
used to checkfor Voltage at other points in the circuit. The
test light will light when the test probe contacts a Voltage
source, and current flows from the Voltage source to ground
(GND).
With one probe contacting a known source
of Voltage, the
other probe can be used to check for continuity to ground
(GND) at other points in the circuit. Current will flow and the
test light will light when the test-point provides the known
Voltage source with a path to ground (GND).
Caution
A common test light (with incandescent bulb) may no
longerbe used.
The bulb's highcurrentdraw will damage
sensitive electronic components.

LED Test Light (US 1115)
Used to check for Voltage reaching components or when
searching for malfunctions in a circuit.
Voltage range: 3 to 48 VDC
CAUTION
A common test light (with incandescent bulb} may no
longer
be used. The bulb's highcurrentdraw willdamage
sensitive electronic components.
Note
This tool has been superseded by Special Tool VAG
15278, LED Tester. (US 1115 is still considered an
acceptable equivalent
to VAG 15278).
LED Tester (VAG 15278)
Order Number: TAG 152 780 28 ZEL
Two-pole Voltage tester with two LEOs (light emitting diodes),
suitable for measuring from 3 to 48 Volts DC or AC.
When used to test
DC circuits, the positive(+) or negative(-)
LED will light, depending on polarity. When used to test AC
circuits, both LEOs will light.
Supplied with banana clip and detachable probe-can be used
directly with VAG 1598 Test Box.
For troubleshooting all common electrical and electronic
components in automobiles. Safe for testing electronic
components and circuits because of extremely low current
consumption (1 .5 rnA maximum).
Voltage range: 3 to 48 Volts (AC
or DC)
CAUTION
A common test light (with incandescent bulb) may no
longerbe used. The bulb's high current draw will damage
sensitive electronic components.
Note
This tool supersedes Special Tool US 1115 LED Test
Light.
IGeneral Information I Test equipment ix

Making an LED Test Light
A lower-cost alternative to buying an LED Test Light such as
US 1115 or VAG 15278 is to make one, using parts available
from most any electronics supply outlet.
Assemble the components as shown. Use needle nose pliers
to hold the parts and to act as a heat dam while soldering.
Insulate the connections with heat-shrinkable tubing
or
electrical tape.
1/4 watt,
3300hm
resistor
Do-it-yourselfLED Test Light for safely testing sensitive solid-
state circuits.
Parts:
1. LED(1)
2. 1/4 watt, 330 0 resistor (1}
3. Alligator clips (2)
4. Wire, Solder and Soldering Iron
5. Heat-shrinkable tubing or electrical tape
x Test equipment IGeneral Information I
2.2 Multimeter or Volt/Ohm Meter
(VOM)
A multimeter or Volt-Ohm meter (VOM) is used to measure
Voltage, resistance (Ohms) or current (amps or millamps).
Two types of meters are in common use. The analog or
swing-needle Volt-Ohm meter displays test values according
to the position of a needle on the meter face. A digital
multimeter displays test values as numbers. The meters
shown here and recommended are digital multimeters.
Accuracy is an important consideration when choosing a
meter. Analog or swing-needle Voltmeters are generally rated
for accuracy as a percentage of full-scale on the meter face.
A typical analog meter may be rated as accurate to ± 3% of
full scale. Some analog meters offer 10-Volt and 50-Volt
scales, with no range in between. For 12-Volt automotive
electrical systems, this means testing on the 50-Volt scale,
with a corresponding decrease in accuracy. On a 50-Volt
scale, ± 3% accuracy is equal to ± 1.5 Volts. While still useful
for testing circuits such as lights and horns, analog meters
may not be accurate enough for use where precise measure-
ments are required.
Digital multimeters are preferred for precise measurement and
for electronics work because most digital multimeters are
more accurate then most analog meters. Another advantage
of digital multimeters is that they are less likely to be misread,
since there is no needle position to
be misinterpreted or
distorted by reading at an angle.
Perhaps the most important consideration is input impedance-
how much of a load the meter places on the circuit being
tested. Meters with low input impedance place a greater load
on the circuit because they allow more currentflow through
the meter. This can exceed design limits and be damaging to
sensitive electronic components.
Most digital multimeters have very high input impedance-10
megohms (10,000,000 0) or higher-and make their measure-
ments while allowing very little current flow through the meter.
The meter itself is not a load in the circuit, and does not
induce damaging current flow.

Multimeter Kit • digital (US 1119, VAG 1526)
Order Number:
TU1119 000 00 KTM
Used for monitoring electronic engine controls (Example:
setting/checking the idle speed control system) and for
general electrical troubleshooting.
Note
This tool has been superseded by the Fluke 83" Digital
Multimeter. (US 1119
or VAG 1526 are still considered
acceptable equivalents).
Fluke sa• Digital Multlmeter
Order Number: TFL UKE 830 00 RSE
Used for monitoring electronic engine controls (Example:
setting/checking the idle speed control system) and for
general electrical troubleshooting.
- 1
0 Megohm input impedance
- ± 0.3% DC Voltage accuracy
-fully overload-protected
Note
This tool supersedes Special Tool US 1119 Digital
MultimeterKit.
I General Information I Test equipment xi

2.3 Test Kits
Adaptor Kit (VW 1594)
Order Number: TV1 594 400 97 KTM
Used to connect electrical measuring equipment to various
harness connectors in the electrical system.
CAUTION
Test connections made carelessly or withoutpropertools
can damage harness connectors, causing poor connec-
tions and future problems.
xii Test equipment IGeneral Information I
Test Box (VAG 1598)
Order Number: WAG 159 800 00 VOA
Used to perform static and dynamic tests of electrical and
electronic systems without damaging miniature contacts,
especially where limited access to connectors makes testing
difficult.
:J
'
~~-~
~
,
.
·-
. ..
w
Ell U!J
J

Tester (VAG 1466)
Used
to systematically troubleshoot electrical circuits. 2.4 Computer Memory Saver
Used on vehicles with theft-protected radios to prevent the
radio from electronically locking when battery power is
disconnected. Use of this tool eliminates the need to re-
activate the radio (reenterthe correct code) after reconnecting
battery power.
WARNING
Always separate the airbag Voltage supply connector
before using a computermemorysaver. Failure to
do so
may resultin accidentalactivation of the airbag. For more
information, seethe CircuitSection in this manual entitled
Airbag,
or see the RepairManual.
Snap-On
Computer Memory Saver
Part No. YA960
Home-made computer memory saver
j91-A051I
l91-A052j
I General Information I Test equipment xiii

3. Handling Components and
Connectors
Harness Connectors
The harness connectors used throughout the vehicle are
designed to positively lock into place. Press on wire lock as
shown to release the connector.
CAUTION
To disconnect, pull onlyon the connectorbody. Never pull
on the wires themselves.
I91-A051I
Typicalwiringharnessconnector. Push onwirelock(arrow) and
gently
pull on connectorto release.
Making Test Connections
Many electrical troubleshooting tests will require hooking up
to wiring harness connectors, or socket connectors on
electrical components. Test connections made carelessly or
without proper tools can easily damage the connectors,
causing poor connections and future problems.
To avoid connector damage, test connections to wiring
harness connectors must be made using small, flat-blade
terminals which will mate properly with the connectors. The
Special Tools recommended include special adapters which
can be used to make test connections safely and prevent
connector damage. See 2. Test Equipment.
All test connections to harness connectors should be made
using the proper adapter or correct size flat connectors that
will not deform the connector cavities.
Alligator-clip test leads with flat connectors
(Part Number: N 17 457 2)
xiv Components and connectors I General Information I