1987 PORSCHE 944 sensor

INDEX
A
ABS Acceleration diagram Accelerator pedal Air Bag System Air - cleaner
- conditioner
- filter
Alternator warning light Antifreeze Antilock, Brake system Anti-theft alarm Ashtray Automatic- garage door
- speed control
- transmission
- transmission fluid B
Battery
Boost pressure gauge
Brake - booster
- fluid
- fluid warning light
- pads
- parking
- pedal
- system
- warning light
Break-in hints
Bulb replacing
Buzzer 28,39
118-129
55
20, 21, 38, 3980, 8144-4680,81 39
74,75,11028, 39
11
42, 98
25
29
53-55
78,110,128
90-9234
27
39,79,11039
27,37,47,79,80 26
26, 27
26,27,11537
47
93-98
10,18,24,30
C/D
CASIS
Capacities
Car care instructions
Casis
Catalytic Converter
Cautions
Central locking
Central warning light
Cigarette lighter
Cleaning
Clock
Clutch pedal
Collapsible spare tire
Control warning light system
Coolant Temperature Gauge
Cooling system
Corrosion prevention
Dashboard
Defogging/defrosting
Dimensions
Doors
Driving hints
E/F
Electrical system
Emergency- flasher
- starting
Emission Control System
Engine - cooling
- exhaust
- hood
- number
- oil checking & changing
- oil
-speed, max 35
110
61-66
35
50,10267
13
37
41
61-66 40
27
85
36-39 36
74-77
65-66
24
44-46 114
12,138-9, 48, 49
89-92
41
92
100-103 74-77
48
586
69-72
69,110,111,128
34,47,52,106-
108
Fan control switch knob
Fan, radiator
Filling capacities
Fog lights
Fuel - economy
- evaporation control
- gauge
- recommendation
- tank
Fuses and relays
G/H
Gas Station Information
Gasohol
Gasoline
Gear ratio diagram
Gearshift lever
Glove compartment
Hatchback
Headlights
Headlight- dimmer
- flasher
- switch
- washing system
Heater/ventilation controls
Hood - front
- rear
Horn
I/J
Ignition/steering lock
Instrument illumination
Instruments
Interior ligh 44
36, 74 110
30, 96, 97
49
103 37
50, 51
50,110
89,126
126-129 51
50,51
122-125 52-55
42
56
30,95,99 30
30
30
31,32,81,11044-4658
56,57
21,24
24
30
33-40
43, 98
4

Jack
- supports
K/L
Keys
Kickdown
Lane changer
Leather
License plate light
Light switch
Lights - ashtray
- fog
- interior
- license plate
- parking
- turn signal
Locks - doors, wheels
Loudspeakers
Lubricants
Luggage compartment
M/O
Manual transmission
- oil
Mirrors
Oil- change
- consumption
- filter changing
- pressure gauge
- pressure warning light
Octane rating
Oxygen Sensor
P/R
Paint code number 68
87, 88, 129
10-11,86 55
30
65
98
30
98
30, 96, 97
43, 9898
30, 37, 93, 94
30,93,94
10-13, 86 89
110,111 57
52,122-125 77,11022,43
71,72
47, 69
71, 72 38
38
50, 51,106-108 101,102
7
Parking- brake
- lights
Performance
Power assisted steering
Power train
Power windows
Prop-up roof
Radiator fan
Rear - hood
- view mirrors
- window defogger
- wiper
Recirculation Switch
Refrigerant
Relays
Rims
Roof racks
Roof, removable S
Safe driving hints
Safetybelts
Safety belt warning light
Safety compliance sticker
Seat heating System
Seats
Sekuriflex windshield
Shift indicator
Shift points
Side marker lights
Ski racks
Snow- chains
- tires
Spare tire, collapsible
Spark plugs
Specifications, engine
26, 3730,37,93,94116731091259, 6036, 7456,572241424446,11089,12664,112,11357,11459, 60
8-9
17-21,6518,3771514-1631, 63, 643552-559457,11483, 84,112,113
83,84, 111,113
85106-108106-109
Speedometer
Starting procedures
Sun visors
T/U
Tachometer
Technical data
Tirepressure
Tires
Tool kit
Trip odometer
Transmission oil
Trunk
Turn signal lights
Undercoating
Unleaded fuel
V/W
Vehicle identification
Ventilation
Voltmeter
Warning/indicator lights
Washer reservoir
Washing
Water temperature gauge
Weatherstrips
Weights
Wheel alignment
Wheel nuts, lockable
Wheels
Wheel changing
Windows
Windshield- washer reservoir
- wiper/washer lever 3324, 2543
34, 35105-12582,112,113,12947,82-87,112,113683377, 78,11056,5730, 37, 93, 9465, 66,10050, 51,106-108,110
6-744-463835-4081,11061-6636641141158647,64,82-87,11285-8812,63,6481,11031
5

Air Bag System

The "Air Bag" in combination with the safety
belt makes up a passive safety system which
offers the driver and front seat passenger the
greatest known protection from injuries in
case of accident.
The air bag system is composed of the
following 3 major groups:
Air bag with gas generator and ignition unit Control electronics Collision sensors
In case of frontal collision greater than a
certain severity, the collision sensors send a
signal via the control electronics to the igni- tion mechanism. In the ignition process, a
solid propellant in the gas generator is
combusted in a fraction of a second. This
combustion generates the gas quantity and
pressure necessary to fill the air bag.
The air bag is located behind the steering
wheel center pad on the driver's side, and on the passenger side behind the padding above
the glove compartment. Due to the rapid
deflation of the air bag after use, there is little
danger of obstructed vision. Likewise, the
noise of the inflation of the air bag generally
goes unnoticed because of the collision noise. The air bag protects the face and upper body,
and at the same time dampens the forward
motion of the driver and passenger.

Range of Effectiveness Even if your vehicle is equipped with an air bag, the safety belt must be worn, since the air bag system is only actuated by frontal collisions and at speeds of more than 13 to 19 mph (depending on collision angle). See
figure for range of effectiveness.
Below the actuation threshold of the air bag
system, and during types of collisions which
do not cause the actuation of the system, the
seat belts provide the primary protection to the occupants when correctly worn. Therefore, all persons within the vehicle should always
wear safety belts (in many states, state law
requires the use of safety belts). See also the
chapter "Safety Belts".
20

Maintenance / Monitor Lights
The air bag system monitors the operational
readiness of the igniter, sensors, warning
lamp, and control electronics itself.
Any malfunctions which may arise are announced by the monitor lights in the right
instrument cluster. Upon activation of the
vehicle ignition circuit, the "Air Bag" notation in
the instrument cluster lights up for
approximately 5 seconds and then goes out
again, indicating system readiness.
In the following cases you should immediately
consult an authorized Porsche dealer in order
to assure the air bag system is functioning
properly:
Illumination of the "Air Bag" light during travel
or repeated illumination longer than 5
seconds after the ignition circuit is turned on.
Illumination fails to light up during ignition
circuit activation.
In order to ensure long-
term functioning, the air bag system must be inspected by an
authorized Porsche dealer after 4, 8 and 10
years from the date of manufacture shown on
the safety compliance sticker, and then every 2 years.
WARNING
No changes must be made to the wiring or components of the air bag system. Do not
add any additional coverings or stickers to the steering wheel or in the area of the
passenger side air bag. Doing so may
adversely affect the functioning of the air
bag system.

Do not undertake any wiring for electrical accessory equipment in the vicinity of the air bag wiring harness. Doing so may
disable the air bag system.
The actuation of the air bag requires the immediate inspection of the system and
replacement of some parts of the system.
See your authorized Porsche dealer.
Defects should be repaired immediately. See your authorized Porsche dealer. When disposing of a used air bag unit, our safety instructions must be followed. These instructions can be obtained at any authorized Porsche dealer.

Important:
If you sell your Porsche, notify the
purchaser that the vehicle is equipped
with an air bag, and refer him or her to the
chapter, "Air Bag System", in the owner's
manual (safety and disposal rules).
Further information on the air bag system can
be found on stickers in the glove
compartment, at the interior light, as well as
on all air bag components.

Horn Button


In vehicles equipped with an AIR BAG, the
horn buttons are mounted in the two upper
spokes of the steering wheel (arrow).
21

Rear View Mirrors

Do not put decals or other signs on the
windows that may interfere with the driver's
vision.
Adjust the outside and inside mirrors before driving. It is important for safe driving that you have good vision to the rear.
Inside day-night mirror

You can adjust the day-
night mirror from clear daylight visibility to non-glare visibility at night by moving the lever at the bottom of the
mirror forward or rearward.
Heated outside mirrors with remote
control


When you turn on the rear window defogger,
the outside rear view mirror is also heated.
The outside mirrors are ad
justable from inside of the vehicle by a four direction switch
located on the left door and a rocker switch
located on the center console ahead of the
gear selection lever. The rocker switch (A)
selects either the left or right mirror for
adjustment. Push
the rocker switch forward to select the left mirror, and rearward to select
the right mirror. Then the four direction switch
will adjust the selected mirror in any of the four directions.
The mirror housing is hinged and can be
folded flat against the c
ar in either direction to prevent damage in tight parking spots.
If necessary, the outside mirrors can also be
adjusted manually.
22

1 Side-window vents 2 Fog light switch
3 Instrument illumination dimmer control
4 Turn signal / headlight dimmer and flasher
switch
5
Left instrument cluster / coolant temperature gauge and fuel gauge
6 Speedometer
7 Central warning light
8 Tachometer
9 Right instrument cluster / oil pressure gauge and voltmeter

10 Intermittent wiper control
11 Rear window defogger switch
12 Fresh air vents
13 Center dashboard vent cut -
off slide14 Temperature rotary switch
15 Emergency flasher switch
16 Glove compartment lock
17 Hatchback release switch
18 Front hood release
19 Light switch
20 Horn
21 Turn signal indicator


22 Ignition / steering lock
23 Wiper / washer lever
24 Trip odometer reset
25
Air volume control knob / defroster switch
26 Fan switch
27 Heating and ventilation control levers -
dashboard / floor
28
Air conditioning switch
29 Clock
30 Cigarette lighter
31 Temperature sensor

23

Ignition/Starter Switch with Steering Lock
The steering is equipped with an anti-theft
ignition lock.
Switch positions
0
The steering is blocked by the steering lock: all circuits wired through the ignition
are switched off.
The ignition key can only be withdrawn in the
"0" position. The parking lights can be
operated in this position by pushing the turn
signal indicator lever up and down (also see
"Parking lights").
1 Position for radio. Steering unlocked. If it is difficult to turn the key, gently move the
steering wheel until the key turns freely.
Note: all circuits which are disconnected in
position "3" can be switched on.
To conserve battery power, switch off other
electrical consumers while playing radio in
position "1".
2
Ignition on. All electric circuits are
operational. With the engine stationary, the
central warning light and all individual
warning lights located in both combination
instruments will light up for a bulb check.
3
The starter is operated by turning the
ignition key to the right. As soon as the
engine starts, release the key. It will spring
back to position "2". With the engine
running, the central and individual warning
lights should go out (see "Central warning
light").
To conserve battery power, the electric
circuits for headlights, rear window de-
fogger/defroster, temperature control and
wiper/washer system are temporarily interrupted during the starting process.
The starter should not be operated for more
than 10 to 15 seconds at a time. If the engine
does not start the first time or stalls at any
time, the ignition key must be returned to the
"0" position. The non-repeat lock in the switch
prevents the
starter from being operated when the engine is running and guards against
starter damage.
To remove the key and to lock the steering
wheel
, turn the key back to position "0" and
pull out. Turn the steering wheel until it locks.

WARNING
Never remove key from ignition lock or
turn key off while vehicle is moving. The
steering wheel will lock, causing loss of
control.
Instrument panel lights
Warning lights for alternator, oil pressure, and
brake system will light up for a bulb check
when the ignition is turned on. They should go out after the engine is started. The brake
warning light will go out after the parking
brake has been fully released. See
"Warning lights" for more details.
Buzzer
If you leave the key in the ignition/steering
lock, the buzzer will sound when the driver's
door is opened. This is a reminder to remove
the key.
For further details see "Starting Procedures"
on the following page.

24

Starting Procedures

WARNING
Fasten safety belts before driving.
Never start or let the engine run in an enclosed, unventilated area. Exhaust
fumes from the engine contain carbon
monoxide, which is a colorless and
odorless gas. Carbon monoxide can be
fatal if inhaled.

Never leave engine idling unattended. An unattended vehicle with a running engine
is potentially hazardous.
Do not park or operate the vehicle in areas where the hot exhaust system may
come in contact with dry grass, brush,
fuel spill or other flammable material.
Never leave engine idling. When starting engine, be ready to drive immediately.
Maintain moderate speed until engine is
warm.

Automatic Transmission - Start with selec-
tor lever in Park.
Manual Transmission - Start with gearshift
lever in Neutral.
Temperature sensors on the engine auto- matically provide the correct fuel/air mixture
required for starting.
Therefore, do not depress the accelerator
pedal while starting a cold or a warm engine.
When starting at very low outside
temperatures , fully depress the clutch pedal,
so that the starter only has to crank the
engine.
As soon as the engine starts, release the ignition key.
If the engine fails to start after 10 to 15
seconds of cranking, wait about 10
seconds before engaging starter again.
Do not let engine idle to warm it up. After
starting, drive vehicle at moderate speeds and with gradual accelerations. Avoid high rpm
and full throttle operation until the engine has
reached normal operating temperature.
Stopping engine
Turn key back to position 0.
Do not stop engine immediately after hard
or extended driving. Keep engine running
at increased idle for about two minutes to
prevent excessive heat buildup before
turning off engine.
WARNING
Before you check anything in the engine compartment, let the engine cool down.
Hot components can burn skin on
contact.

The radiator fan switches on automatically when the coolant reaches a
certain temperature and continues to run
(even with ignition off) until the coolant
temperature drops. Therefore, never
touch the fan blades as they will rotate
spontaneously when the thermoswitch
turns the fan on.

If you have an automatic garage door...
The transistorized ignition system in your
Porsche may interfere with your electronically
operated garage door. To check this: drive
your Porsche close to the garage door and
run the engine at different speeds.
If the garage door opens or closes without
your operating the garage door unit in your
car, contact the dealer who installed the
automatic garage door to have the frequency
and/or coding of the garage door signal
modified.
25

ABS Brake System (Antilock brake system)
The ABS system represents a major
contribution to the enhancement of active
safety in your vehicle. This system prevents
the wheels from locking in a panic stop on
almost all road surfaces.
With ABS system in your vehicle, the
following areas are enhanced:
Full steerability , vehicle remains steerable
under all braking forces.
Good directional control , no swerving
caused by locking of wheels under braking
conditions.
Excellent stopping distance , stopping
distances are usually reduced because
controlled braking is maximized.
Prevention of wheel lock up , no brake-
induced sliding and thus no localized tire wear from emergency braking.
The crucial advantage of ABS system over a
conventional brake system is in the area of
maintaining directional control and
maneuverability of the car in emergency
situations, including panic braking in turns.
WARNING:
In spite of the improved handling afforded
by the ABS system, it still remains the
responsibility of the driver to adapt the
driving style to the prevailing road and
weather conditions, as well as, obeying
traffic laws. In no case, should the higher
degree of safety offered by ABS be
regarded as a

justification for taking greater risks. Other vehicles not equipped with the ABS
system may not be able to maintain
control, especially on wet or poor road
surfaces and thus may be more likely to
impact you in the rear. To minimize that r
isk, use your ABS system to increase your ability to maneuver to avoid dangerous
situations and not merely to try to stop in
the shortest distance possible.
Driving with the ABS System
A wheel speed sensor is fitted to each of the four wheels. If wheel slippage of either of the
front wheels or the rear wheels is sensed
during braking, the brake pressure is adjusted
automatically until the wheel no longer slips.
The brake pressure is regulated for each front
wheel individually and for both rear wheels together.
On a road surface which is slippery on only
one side, the rear wheel which is braking on
the slippery surface determines the brake
pressure which will be applied equally to both
rear wheels. This ensures that directional
stability is maintained. However, if braking
force approaches the wheel locking-up point
for all wheels (panic braking) the ABS system
will intervene in a way comparable with rapid rhythmic braking. The proper operation of ABS is perceived by the driver as a pulsating brake pedal in conjunction with audible noise
and perhaps some vibration. The driver is
thereby warned to reduce vehicle speed
appropriate for the prevailing road conditions.

If your ABS system should ever malfunction,
the ABS system is automatically switched off,
but the normal brake system, without ABS,
would remain fully operational. Such a malfunction would be indicated by the illumination of the central warning light, as well as the "ANTILOCK" light on the right hand
side of the instrument cluster.
If the ABS system becomes inoperative,
take your vehicle to your authorized dealer immediately.
Note
The control unit of the ABS brake system is
set for standard tire sizes. If non-standard
tires are fitted, the control unit may
misinterpret the speed of the vehicle, because of the variant data it receives from the sensors on the axles.
If the difference in rolling radius exceeds
approx. 17%, the control unit deactivates the
ABS system and the ABS warning lamp lights up.
28


1 Set accelerate
2 Reset
3 Cancel

Automatic Speed Control
The automatic speed control allows you to
maintain a constant cruising speed of 25 mph
(40 km/h) or higher, without actuating the
accelerator pedal. Any manual operation,
such as accelerating, gearshifting or braking
can be done independent of the automatic
speed control. The spring loaded control lever
operating the automatic speed control is
located just below the wiper/ washer lever.
While driving with the automatic speed
control set at speeds above 25 mph (40
km/ h), do not bring shift lever into the
Neutral position as excessive engine rpm
will result.
To operate the automatic speed control Accelerate to the desired cruising speed, push lever toward instrument cluster (arrow 1) and
release. This sets the cruising speed and
stores it in a memory.
After a second or two, automatic speed control will take over and you can remove
your foot from the accelerator pedal. The set
cruising speed will be maintained
automatically.
WARNING
Do not use the cruise control when it may
be unsafe to keep the car at a constant
speed. For example, a constant speed may not be safe in heavy traffic, or on winding
or slippery roads. With the cruise control
system engaged, the engine speed will not
return to idle when removing the foot from
the accelerator pedal.
Please observe all local and national speed limits.

Passing: If you want to drive faster for a brief
moment, for example when passing another
vehicle, actuate the accelerator. When you
take your foot off the accelerator pedal, the
preset speed will automatically be resumed.
Gearshifting: When shifting gears, the
automatic speed control is only disengag
ed as long as the clutch pedal is depressed. The
preset speed will be resumed as soon as you
take your foot off the clutch pedal.
Braking and stopping: Whenever you apply
the brake or come to a stop, the automatic
speed control is disengaged. Move the lever
down (arrow 2), and the preset speed will be
resumed.

Switching system off: To switch off the
automatic speed control, move the lever
toward you (arrow 3). To resume the preset
speed, move the lever down (arrow 2).
To change the preset cruising speed
Increase preset speed:
Accelerate by depressing the accelerator pedal. When the desired speed is reached push lever toward instrument cluster (arrow 1) and take your foot off the accelerator pedal.
Now the new cruising speed is set and stored
in the memory. As an alternative, you can hold the lever in the front position (arrow 1), without depressing the accelerator pedal. The car will
accelerate on its own. When the desired
speed is reached, release the lever.
Decrease preset speed:
Apply the brake, which will disengage the automatic speed control. When the vehicle
has slowed down to the desired speed, push
lever toward instrument cluster (arrow 1) to
set the new cruising speed.
As an alternative, disengage the automatic
speed control by moving the lever toward you
(arrow 3). When the vehicle has slowed down
to the desired speed, push lever toward
instrument cluster (arrow 1) to register the
new cruising speed in the memory.
Note: When driving up a hill, if the engine
power is insufficient in a particular gear, the
speed control will be disengaged
automatically. Shift to a lower gear to avoid
stalling the engine.

29

Automatically Controlled
Air Conditioner
The air conditioning system works only when
the engine is running. Its refrigerating capacity depends on engine speed. If a high
refrigerating capacity is desired, it is
necessary to rev up the engine -
particularly in city or bumper-to-bumper traffic.
The air conditioning system can be turned on
at any air distribution position by pressing the
air conditioner switch. When the system is
turned on, the air conditioning compressor is
activated via a magnetic clutch.
Optimal cooling is achieved when the fan
control switch is at position 4, the windows are closed and the lateral as well as the
center dashboard vents are fully opened and
the temperature switch is set at maximum
cooling power.
When the air conditioning system is on,
additional cooled air enters the glove
compartment through a vent.
After prolonged exposure to sun, it is recommended that you ventilate the
passenger compartment with the windows
down and air conditioning on.
Should the air conditioning system fail, i. e.
uncooled air flows through the vents while the
system is switched on, have it checked in an
authorized workshop.


45

Functioning
The automatic system controls the passenger
compartment temperature in accordance with
the temperature preset by the temperature
knob.
The passenger compartment temperature is
kept constant under varying climatic
conditions.
Cold and warm air is automatically mixed by
means of air flaps operated by a servo motor.
The servo motor is controlled by a passenger
compartment temperature sensor, an ambient
temperature sensor and a temperature sensor located in the air conditioner.
There are several options to satisfy the
requirements of individual comfort with an
automatically controlled air-conditioning
system:
The upper level (2) is operated to direct the air flow towards the windshield (right position:
open; left position: closed).
The lower level (3) can be used to direct the
air flow to the footwell outlets (right position:
open; left position: closed). The positions of
these two levers are infinitely variable and can be set independently of one another. A higher or lower temperature range can be preselected by means of the temperature
control knob.

Air Conditioning System Maintenance The air conditioning system must be turned on for a short period of time at least once a
month. This instruction should be observed
particularly during the cold season to ensure
proper lubrication of the sealing rings and
compressor bearings.
For this purpose, set the temperature control
knob at maximum cooling temperature
(extreme counterclockwise position).
Check the compressor polyrib belt for proper
tension during regular maintenance.
Due to the loss of refrigerant, which is
technically inevitable, the refrigerant level in
the fluid reservoir should be checked at least
once a year.
If gas bubbles are visible over an extended
period of time in the inspection window of the
fluid reservoir while the air conditioner is
running, there is a deficit of refrigerant in the
air conditioning system. The brief appearance
of gas bubbles is due to technical reasons.
Should the air conditioning system fail, i. e.
uncooled air flows through the vents while the
system is switched on, have it checked by
your Porsche dealer.


46

How Emission Control Works

When an automobile engine is running, it uses energy generated through the combustion of a mixture of air and fuel. Depending on whether
a car is driven fast or slowly or whether the
engine is cold or hot, some of the fuel
(hydrocarbons) may not be burned completely but be discharged into the engine crankcase
or exhaust system. Additional hydrocarbons
may enter the atmosphere through
evaporation of fuel from the fuel tank. These
hydrocarbons (HC), when released into the
air, contribute to undesirable pollution.
In addition, carbon monoxide (CO) and oxides of nitrogen (NOx) contribute to engine
emissions. They, too, are formed during the
combustion process and discharged into the
exhaust system.
To reduce these pollutants, your Porsche is
equipped with a precisely calibrated fuel
injection system to assure a finely balanced
air/fuel mixture under all operating conditions.

Oxygen Sensor
The oxygen sensor, installed in the exhaust
pipe continuously senses the oxygen content
of the exhaust and signals the information to
an electronic control unit. The control unit
corrects the air/fuel ratio, so that the engine
always receives an accurately metered air fuel mixture. .
Crankcase Ventilation
Through Crankcase Ventilation undesirable
emissions from the engine crankcase are not
permitted to reach the outside atmosphere.
These emissions are recirculated from the
crankcase to the air intake system. From here
the emissions mix with the intake air and are
later burned in the engine.
Catalytic converter
The catalytic converter is an efficient
"cleanup" device built into the exhaust system
of the vehicle. The catalytic converter burns
the undesirable pollutants in the exhaust gas
before it is released into the atmosphere.
The exclusive use of unleaded fuel is critically important for the life of the
catalytic converter. Therefore, only
unleaded gasoline without additives must
be used.
The catalytic converter will be damaged by

push or tow starting your vehicle
misfiring of the engine turning off the ignition while the vehicle is moving or
by other unusual operating conditions.
Do not continue to operate your vehicle
under these conditions, as otherwise fuel
can reach the catalytic converter. This
could result in overheating of the
converter.
Federal law prohibits use of leaded
gasoline in this car.
The Emission Control System and its other
related components are illustrated and
described on the following pages.
101

Emission Control System
1 Fuel pump
2 Fuel filter
3 Pressure damper
3a Pressure regulator
4 Injector
5 Auxiliary air valve
6 Air flow meter
7 Throttle valve switch
8 Temperature sensor
9 Engine temperature sensor
10 Speed sensor
11 Reference mark sensor (TDC)
12 Control unit
13 Ring gear
14 Ignition coil
15 Distributor
16 Relay (fuel pump / control unit)
17 Oxygen sensor
18 Catalytic converter
19 Muffler

102