Page 141
196 Combined instrument
Contents
Oil pressure warning lamp (47D) ............ 196
Charging warning lamp (47E) ............... 196
Rheostat (16) a en en a: 197
Fuel gauge and warning lamp (47A, 47B) .... 197
Temperature gauge (47C) .........0..000005 197
Brake fluid level warning lamp (47F)......... 198
EXHiwaming lamp (4 7b) is. a3.5le. cloaca 199
Handbrake warning lamp (47M) ............. 200
Choke warning lamp (470) ................. 200
Check engine warning lamp (47P) ........... 201
Clock (49)2 .i05 soe ee ee 201
Oil pressure warning lamp (47D)
Operation (1987 model)
The oil pressure warning lamp is intended to warn the
driver that the engine oil pressure is below the prede-
termined value.
Lamp 47D in the combined instrument is supplied
(+15) from fuse 22, via 29-pole red connector
1528:
If the lubricating oil pressure should drop below 0.3 -
0.5 bar, oil pressure transmitter 44 will close and the
lamp will light up.
Operation (1988 model)
The oil pressure warning lamp is intended to warn the
driver that the engine oil pressure is below the prede-
termined value.
Lamp 47D in the combined instrument is supplied
(+54) from fuse 7, via 29-pole red connector 152B.
if the lubricating oil pressure should drop below 0.3 -
0.5 bar, oil pressure transmitter 44 will close and the
lamp will light up.
Fauit-tracing hints
The oil pressure warning lamp will be operative when
the ignition switch is in the drive position.
1. Check fuse 22 (1987) or 7 (1988) and check
that the supply to it is live.
2. Check the bulb and check that the supply to its
terminals in the combined instrument is live.
3. Disconnect the cable from the oil pressure
transmitter and earth it. If the lamp lights up,
the circuit is unbroken.
4. Check the connectors, cable harnesses and the
earth connection of the oil pressure transmitter.
Charging warning lamp (47E)
Operation
The charging warning lamp informs the driver of
whether or not the alternator is charging.
When the ignition switch is in the drive position, a
positive voltage will be supplied via fuse 7 and red
29-pole connector 152B to charging warning lamp
47E in the combined instrument. The other side of
the lamp is connected to alternator 2.
When the alternator is not rotating or when it is not
charging the battery for any other reason, the circuit
for the charging warning lamp will be earthed through
terminal D+ onthe alternator, ana the lamp will light
up.
When the alternator is charging, terminal D+ will be
at the same voltage as the supply from the fuse. The
same voltage will then be applied to both terminals of
the warning lamp, and the lamp will therefore be
extinguished.
For complete information, see the section entitled
"Engine electronics, Battery-charging system”.
Fauit-tracing hints
1. Check fuse 7 and check that the supply to it is
live.
2. Check that the bulb in the warning lamp is in-
tact.
3. Check the connectors, cable harnesses and the
earth connections of the alternator.
4. Check that terminal D+ of the alternator is live.
Saab 900
Page 142
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Combined instrument 197
Rheostat 16
Operation
When the ignition switch is in the drive position,
rheostat 16 is supplied via 29-pole red connector
152B and fuse 10.
The brightness of the following instrument lighting
can be steplessly adjusted by means of rheostat 16
in combined instrument 47:
18 Combined instrument lighting
148 Ashtray illumination
ips Lighting for the cigarette lighter
154 Lighting for the heater controls
In addition, the dial lighting for the radio (267) con-
nected to connector 98 is adjusted via rheostat 16.
For complete information, see the section entitled
"Lighting systems, Lighting for controls”.
Fault-tracing hints
1. Check the appropriate fuses and check that the
supply to them is live.
2. Check the bulbs and check that the supply to
them is live.
3. Check the connectors, cable harnesses and
earth connections.
Fuel gauge and warning lamp
(47A, 47B)
Operation
The fuel gauge and the warning lamp for the fuel
reserve keep the driver informed of the fuel level in
the tank.
When the ignition switch is in the drive position, a
positive supply (+15) is taken from fuse 22 to:
® Fuel level gauge 47A in the combined instrument
and then through a 3-pole connector (57) to fuel
level transmitter 46 in the fuel tank to earth, and
® Fuel reserve warning lamp 47B and then through
the fuel level transmitter in the fuel tank to earth.
Fuel level transmitter 46 adjusts the voltage so that
the fuel gauge reading will correspond to the level
sensed by the transmitter float in the tank.
When the fuel content of the tank has dropped to
about 7 dm (litres) or less, the fuel reserve warning
lamp will be earthed through the transmitter and the
lamp will light up.
Fault-tracing hints
The fuel gauge and the warning lamp for the fuel
reserve will be operative when the ignition switch is in
the drive position.
1. Check fuse 22 and check that the supply to it is
live.
2. Check the bulb and check that the supply to its
terminals in the combined instrument is live.
3. Check that the terminals of the fuel gauge and
the fuel level transmitter are live.
4. Check the connectors, cable harnesses and the
earth connection of the fuel level transmitter.
Resistance of the fuel level transmitter
3.2 + 0.7 ohm when the tank is full
65.4 + 2.1 ohm when the tank is empty
Temperature gauge (47C)
Operation
The temperature gauge shows the engine coolant
temperature.
When the ignition switch is in the drive position,
coolant temperature gauge 47C is supplied (+15)
from fuse 22. The other terminal of the gauge is
earthed via coolant temperature transmitter 45.
Changes in the coolant temperature will affect the
resistance of the transmitter, and the gauge will thus
show the prevailing engine temperature.
Fauit-tracing hints
The temperature gauge will be operative when the
ignition switch is in the drive position.
1. Check fuse 22 and check that the supply to it is
live.
2. Check that the supply to the temperature gauge
is live.
3. Check that there is no open circuit in transmitter
45.
4. Check the connectors, cable harnesses and
earth connections.
Resistance of the temperature transmitter:
51.2 + 4.3 ohm at 90° C
Saab 900
Page 143
198 Combined instrument
Brake fluid level warning lamp
(47F)
Operation (1987 model)
The brake fluid level warning lamp is intended to warn
the driver that the brake fluid level in the reservoir is
low. Its operation can be checked by means of a
button on the brake fluid reservoir.
When the ignition switch is in the drive position, lamp
47F is supplied (+54) from fuse 5, via brake warning
switch 42 and 29-pole black connector L520:
If the fluid in the brake fluid reservoir should drop to
an inadmissibly low level, switch 42 will close and
the warning lamp will light up.
Lamp test
When the engine is started by the ignition switch
being turned to the start position, a positive voltage
is supplied from terminal 50 of ignition switch 20.
The current flows through the diode, thus lighting the
lamp. The diodes. prevent the current from flowing
back.
On cars with automatic transmission, the current
also flows through start inhibitor switch CTs
Fault-tracing hints
The brake fluid level warning lamp will be operative
when the ignition switch is in the drive position.
1. Check the brake fluid level warning circuit by
pressing the button on the brake fluid reservoir.
The circuit should close and the lamp should
light up.
2. Check fuse 5 and check that the supply to it is
live.
3. Check the bulb and check that the supply to its
terminals in the combined instrument is live.
4. Check the connectors, cable harnesses and the
earth connection.
Operation (1988 model)
The brake fluid level warning lamp is intended to warn
the driver that the brake fluid level in the reservoir is
low. Its operation can be checked by means of a
button on the brake fluid reservoir.
When the ignition switch is in the drive position, lamp
47F is supplied (+15) from fuse 22, via 29-pole
black connector 152C.
The other side of the lamp is connected to brake
warning switch 42, via 29-pole black connector
1526;
If the fluid in the brake fluid reservoir should drop to
an inadmissibly low level, switch 42 will close and
the warning lamp will light up.
Lamp test
When the ignition switch is turned to the start posi-
tion, terminal 15 of ignition switch 20 supplies pin 9
of lamp 47F, and the anode of the diode in the com-
bined instrument.
In the starting position, the +54 circuit is open, so
that the cathode of the diode in the combined in-
strument is earthed via pins 7, 9 and 8 of lamp 47E,
and via alternator 2. The diode prevents the current
from flowing back.
Fault-tracing hints
The brake fluid level warning lamp will be operative
when the ignition switch is in the drive position.
1. Check the brake fluid level warning circuit by
pressing the button on the brake fluid reservoir.
The circuit should close and the lamp should
light up.
2. Check fuse 22 and check that the supply to it is
live.
3. Check the bulb and check that the supply to its
terminals in the combined instrument is live.
4. Check the connectors, cable harnesses and the
earth connection.
Saab 900
Page 144
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Combined instrument 199
Full beam warning lamp (47G)
See the description in the section entitled "Lighting
systems, Headlamps”.
Direction indicator warning
lamps (47H: left-hand, 471:
right-hand)
See the description in the section entitled ’Lighting
systems, Direction indicators”.
Rear window heater warning
lamp (473)
See the description in the section entitled "Heating
and ventilation systems, Electric heating for the rear
window’.
Shift-up warning lamp (47K)
See the description in the section entitled ”Instru-
ments and warning systems, Shift-up indicator’.
EXH warning lamp (47L) — 1987
I8 Lambda: US, CA, JP, AU
Operation
Cars with 8-valve engines and the Lambda exhaust
gas emission control system are equipped with a
warning lamp (EXH) which reminds the driver that
components of the emission control system require
maintenance.
When the ignition switch is in the drive position, EGR
selector 86 is supplied from fuse 5, via 29-pole red
connector 152B. When the car has travelled about
48 000 km (30 000 miles), the selector will close
and lamp 47Lwill light up. The lamp will then remain
alight until the selector is reset to zero.
Fault-tracing hints
The lamp will be operative when the ignition switch is
in the drive position.
1. Check fuse 5 and check that the supply to it is
live.
2. Check that the selector is live.
Check the lamp.
4. Check the connectors, cable harnesses and
earth connections.
Saab 900
Page 145
ne
200 Combined instrument
Handbrake warning lamp (47M)
Operation
The handbrake warning lamp warns the driver that the
handbrake is applied.
Lamp 47M in the combined instrument is supplied
(+15) from fuse 22 via 29-pole red connector 152B.
As long as the handbrake is applied, handbrake
switch 43 will be closed and the lamp will stay alight.
Lamp test (1987 model - U.S.A., Canada and
Japan)
When the ignition switch is turned to the start posi-
tion, terminal 15 of ignition switch 20 will be live.
Current will flow to pin 7 of lamp 47M and the anode
of diode 84. When the switch is in the start position,
the supply from +54 is opened, and the cathode of
diode 84 is therefore earthed via pins 10 and 9 of
lamp 47E and alternator 2. If lamp 47M is in good
condition, it should then light up. Correct indication
will be obtained only if the handbrake is not applied.
The diode prevents the current from flowing back.
Lamp test (1988 model)
When the ignition switch is turned to the start posi-
tion, terminal 15 of ignition switch 20 will be live.
Current will flow to pin 11 of lamp 47M and the anode
of the diode in the combined instrument.
When the switch is in the start position, the supply
from +54 is opened, and the cathode of the diode in
the combined instrument is therefore earthed via
pins 7, 9 and 8 of lamp 47E and alternator 2.
If lamp 47M is in good condition, it should then light
up. Correct indication will be obtained only if the
handbrake is not applied. The diode prevents the
current from flowing back.
Fault-tracing hints
The handbrake warning lamp will be operative when
the ignition switch is in the drive position.
1. Check fuse 22 and check that the supply to it is
live. Check also fuse 7.
2. Check the bulb and check that the supply to its
terminals in the combined instrument is live.
3. Disconnect the cable from the handbrake switch
and earth it. If the lamp lights up, the circuit is
unbroken.
4. Check the connectors, cable harnesses and the
earth connection of the handbrake switch.
Rear fog light warning lamp
(47N)
See the description in the section entitled "Lighting
systems, Rear fog lights”.
Choke warning lamp (470)
Operation
The choke warning lamp lights when the choke is
partially or totally withdrawn. This lamp is fitted only
to cars with carburetor engines.
When the ignition switch is in the drive position,
choke warning lamp 470 is supplied (+54) from fuse
7, via 29-pole red connector 152B.
When the choke control is withdrawn, switch 34 will
close, and the lamp will light up.
Fault-tracing hints
Choke warning lamp 470 will be operative when the
ignition switch is in the drive position.
1. Check fuse 7 and check that the supply to it is
live.
2. Check the bulb and check that the supply to its
terminals in the combined instrument is live.
3. Disconnect the cable from the choke control
switch and earth it. If the lamp lights up, the
circuit is unbroken.
4. Check the connectors, cable harnesses and
earth connections.
Saab 900
Page 146
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Combined instrument 201
Check engine warning lamp
(47P)
Operation
Should a fault occur in the fuel system and/or ignition
system, flashing codes will be obtained on warning
lamp 47P. This lamp is fitted only to cars with
16-valve engines.
When the ignition switch is in the drive position,
warning lamp 47P is supplied (+54) from fuse 7, via
29-pole red connector 152B. Warning lamp 47P then
supplies control unit 200 for the LH system and/or
control unit 176 for the EZK ignition system.
Warning lamp 47P lights up with a steady light when
the ignition switch is in the drive position, before the
engine is started.
For complete information, see the section entitled
"Engine electronics”, ”LH fuel system” and ”EZK igni-
tion system”.
Fault-tracing hints
Warning lamp 47P will be operative when the ignition
switch is in the drive position.
1. Check fuse 7 and check that the supply to it is
live.
2. Check the bulb and check that the supply to its
terminals in the combined instrument is live.
3. Check the connectors, cable harnesses and
earth connections.
Passive seat-belt warning lamp
(47S)
See the description in the section entitled "Other
systems, passive seat belts”.
Clock (49)
Operation
Clock 49 is located in combined instrument 47. The
positive supply to the clock is taken from fuse 28, via
29-pole red connector 152B. The supply to the clock
is live (+30) regardless of the position of the ignition
switch.
Fault-tracing hints
1. Check fuse 28 and check that the supply to it is
live.
2. Check that the positive terminal of the clock is
live, and that the negative terminal is earthed.
3. Check the connectors, cable harnesses and
earth connection.
Tachometer (110)
See the description in the section entitled "Engine
electronics, Ignition systems”.
Saab 900
Page 147
202 Combined instrument
Locations of components
1
16
18
20
PHAN
22A
34
42
43
44
45
46
ATA
47B
47C
47D
A47E
ATF
47G
47H
47
47J
47K
ATL
47M
47N
470
47P
Battery
on the right-hand side of the engine com-
partment
Alternator
on the left-hand side of the engine
Earthing point in the facia
Earthing point, radiator cross-member
Instrument lighting rheostat
in the combined instrument
Combined instrument lighting
Ignition switch
on the centre console between the front
seats
Ignition switch relay
Fuse holder
in the electrical distribution box, in the en-
gine compartment, on the left-hand wheel
housing
Choke control switch
on the centre console between the front
seats
Brake warning switch
on the brake fluid reservoir
Handbrake switch
under the plastic cover at the handbrake
lever, between the seats
Oil pressure transmitter
on the left-hand side of the engine block,
above the oil filter
Coolant temperature transmitter
on the right-hand side of the thermostat
Fuel level transmitter
in the fuel tank - the terminals are acces-
sible from the luggage compartment
Fuel level gauge
Fuel reserve warning lamp
Coolant temperature gauge
Oil pressure warning lamp
Charging warning lamp
Brake warning lamp
Full beam warning lamp
Left-hand direction indicator warning lamp
Right-hand direction indicator warning lamp
Rear window heater warning lamp
Shift-up warning lamp (US, manual)
EXH warning lamp (1987 I8 Lambda: US, CA,
JP, AU)
Handbrake warning lamp
Rear fog light warning lamp (SE, FI, EU, GB)
Choke warning lamp (C8)
CHECK ENGINE warning lamp (116, 116
Lambda, T16, T16 Lambda)
47S
49
Dil
58
59
60
61
(65)
ThE
83
84
86
110
a Ee tz
152A
152B
152C
158
159
211
257
Passive seat-belt warning lamp (US: 18
Lambda, 116 Lambda)
Clock
3-pole connector
one in the luggage compartment, under the
cover for the spare wheel
one under the back seat, on the left-hand
side (US: I8 Lambda, 116 Lambda)
12-pole connector
on the angle bracket, under the facia on the
left-hand side (behind the knee shield)
2-pole connector (Convertible)
in the electrical distribution box in the en-
gine compartment, on the left-hand wheel
housing
Single-pole connector (auto.)
under the centre console, at the selector
lever
Windscreen wiper stalk switch
on the right-hand side of the steering co-
lumn
Distribution block
in the engine compartment, on the right-
hand side
Start inhibitor switch (auto.)
under the centre console, at the selector
lever
Relay for intermittent operation of the wind-
screen wipers
under the facia, to the left of the steering
column (behind the knee shield)
Diode for brake lamp test (US, CA, JP)
on the handbrake
EGR selector
under the facia, to the left of the steering
column (behind the knee shield)
Tachometer
in the combined instrument
Earthing point
at the handbrake (1987)
between the ignition switch and the hand-
brake (1988)
29-pole white connector’
29-pole red connector
29-pole black connector
Negative distribution terminal
Distribution terminal +15
in the electrical distribution box, in the en-
gine compartment, on the left-hand wheel
housing
Earthing point on the gearbox
Earthing point, alternator bracket
Saab 900
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Page 148
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Combined instrument
203
Components
1987 1988
16 16
18,18 18,18
47A-47M 47A-47K
47N/47S ALN
61(M1987)
(OO
OL
2a
86
Saab 900
Page 149
208
Cigarette lighter
Cigarette lighter
GB, FE, AU
214
BL 0.75
or
1 [11152B
Fe)
214
BL 0.75
© st
a
128 128
SV 0.75 SV 0.75
59 .
318B
SV 0.75
Saab 900
Page 150
Cigarette lighter 209
Operation
When the ignition switch is in the drive position, the
cigarette lighter is supplied from fuse 13, via 29-pole
red connector 152B. The circuit is closed when the
cigarette lighter is depressed.
Fault-tracing hints
1. Check fuse 13 and check that the supply to it is
live.
2. Check that the filament of the cigarette lighter is
unbroken.
3. Check the earth connection.
Saab 900