SAAB 9000. Instruction - page 30

5A•6 Starting and charging systems

11.3a Remove the screws ...

11.3b ... lift off the cover...

11.4 Removing the circlip and shims

11.5 Unscrew the through-bolts . . .

11.7 Removing the brush holder assembly

3 Unscrew and remove the two screws
securing the cover to the end bracket. Lift off
the cover and remove the seal (see
Extract the circlip, and remove the shim(s)
and O-ring seal (see illustration).
Unscrew the through-bolts securing the
commutator end bracket and yoke to the
pinion end bracket (see illustration). Mark the
end bracket in relation to the yoke.
6 Remove the commutator end bracket (see
Withdraw the brush holder assembly, at the
same time releasing the feed cable grommet
from the yoke. If the commutator/armature
requires attention or cleaning, withdraw it from
the yoke at this stage, then remove the brush
holder assembly (see illustration). As the
holder assembly is removed, the brushes will

be pushed out of their holders by the springs,
but will be retained by the leads.

8 Check the brushes for wear, and renew as
necessary. It may be possible to obtain

11.9 Fitting the brush holders

individual brushes from a motor factor,
otherwise the complete brush holder may
have to be renewed. Clean all the components
before reassembly. Clean the commutator
using fine glasspaper. If it is worn excessively,
it may be possible to have it machined by an
auto-electrician. Make sure that the brush
holders are thoroughly cleaned, so that the
new brushes will move freely in them.
9 Locate the brush plate without the brush
holders part-way onto the commutator, then
centralise the brushes, and fit the holders and
springs over the brushes (see illustration).
If removed, refit the armature inside the
11 Slide the complete bush holder assembly
onto the armature commutator, while guiding
the feed cable grommet in the yoke slot.
12 Locate the commutator end bracket on
the armature, followed by the O-ring seal,
shim(s) and circlip. Make sure that the O-ring
seal is correctly fitted.
13 Refit the end bracket, making sure that the

11.3c . . . and remove the seal

11.6... and remove the commutator end


mark is aligned with the previously-made mark
on the yoke. Insert and tighten the through-
14 Refit the shims and circlip, then refit the
cover and seal to the end bracket, and tighten
the two screws.
15 Reconnect the feed cable to the solenoid
terminal, and tighten the nut.
16 Refit the starter motor with reference to
Section 10.


1 Refer to Chapter 10 and remove the ignition
switch/steering column lock.

2 To remove the ignition switch, unscrew the
socket-headed screws, and withdraw the
switch from the lock housing.
3 The lock cylinder may be removed by first
inserting the ignition key and turning it to
position "1". Using a suitable instrument
through the hole provided, depress the locking
tab, then withdraw the lock cylinder from the


4 To refit the lock cylinder, push it into the
housing until the locking tab is engaged.
5 Locate the ignition switch on the housing,
and tighten the two socket-headed screws.
6 Refer to Chapter 10 for details of refitting
the ignition switch/steering column lock.


Chapter 5 Part B: Ignition system


Crankshaft sensor (DI/APC system) - removal and refitting 10

Distributor (Hall-effect system) - removal, overhaul and refitting . . . 4
Electronic control unit (DI/APC system) - removal and refitting . . . . 13
General information 1
Ignition cartridge (DI/APC system) - removal and refitting 6
Ignition HT coil (Hall-effect system) - removal, testing and refitting . 3
Ignition HT coils (DI/APC system) - removal and refitting 7
Ignition system amplifier unit (Hall-effect system) - removal and

refitting 5

Ignition system check See Chapter 1
Ignition system - testing 2
Ignition timing - checking and adjustment 14
Knock detector (DI/APC system) - removal and refitting 8
Pressure sensor (DI/APC system) - removal and refitting 12
Slotted rotor for crankshaft sensor (DI/APC system) - removal and

refitting 11

Solenoid valve (DI/APC system) - removal and refitting 9
Spark plug renewal See Chapter 1


System type

Models manufactured up to approx 1989 Hall-effect ignition system with Bosch LH-Jetronic
Models manufactured from approx 1989 to 1993 (1985 cc)

or to 1992 (2290 cc) Direct Ignition (Dl) system with Bosch LH-Jetronic

Models manufactured from 1994 (1985 cc) or from 1993 (2290 cc). .. . Direct Ignition (Dl) system incorporated in Trionic engine management


Hall-effect ignition system

Ignition HT coil winding resistances:

Primary 0.52 to 0.76 ohms


Up to approx 1986 2400 to 3500 ohms
From approx 1986 7200 to 8200 ohms

HT lead resistances:

Coil-to-distributor 500 to 1500 ohms
Distributor-to-spark plug 2000 to 4000 ohms

Ignition timing (vacuum control disconnected):

Non-turbo models 14° BTDC @ 850 rpm

Turbo models 16° BTDC @ 850 rpm

Rotor arm resistance 1000 ohms

Direct Ignition (Dl) system

Ignition discharge cartridge:

Capacitor voltage 400 volts
Ignition voltage (maximum) 40 000 volts

Ignition timing Pre-programmed in ECU

Firing Order 1-3-4-2 (No 1 cylinder at timing chain end)

Torque wrench settings Mm lbf ft

Crankshaft pulley bolt 190 140
Ignition cartridge (discharge module) 12 9
Knock detector 13±2 10±1.5
Spark plugs 28 21

Degrees of difficulty

5B•2 Ignition system

Models manufactured up to approximately

1989 are fitted with a Hall-effect breakerless
ignition system, and these models are fitted

with the Bosch LH-Jetronic fuel injection
system described in Chapter 4. The Hall-effect
ignition and the LH-Jetronic fuel injection
systems operate independently of each other.

Models manufactured from approximately

1989 to 1993 (1985 cc) or from 1992 (2290 cc)

are fitted with a Direct Ignition (Dl) system.
This system has its own electronic control unit
(ECU), but additionally uses information from
the Bosch LH-Jetronic fuel injection system

ECU to control ignition timing.

Models manufactured from 1993 (2290 cc) or

from 1994 (1985 cc) onwards have a Direct
Ignition system which is incorporated into the

Trionic engine management system. With this

system, a single electronic control unit (ECU)
controls both the fuel injection and ignition
functions. The Trionic system was originally fitted
to Turbo models only, but from 1994 it is also
fitted to non-turbo engines. More information on
the Trionic system is given in Chapter 4.

Hall-effect ignition system

The system is a breakerless electronic

ignition system (see illustration), and

comprises an impulse generator (Hall sensor in
the distributor), an amplifier, the coil and spark
plugs. The impulse generator uses the Hall-
effect method to send signals to the amplifier,
which then switches the low-tension circuit by
means of transistors. The amplifier also
monitors and regulates the ignition dwell angle.

A separate ignition pulse amplifier (located

behind the glovebox) was introduced in 1986,

to reduce the effects of radio interference, and
to provide better control of the system.

The distributor incorporates centrifugal

advance weights, to automatically advance

the ignition timing according to the engine
speed. On some models (depending on
country), the distributor also incorporates a
double-acting vacuum capsule, which adjusts
the ignition timing according to the load on the

engine. The conventional vacuum control

advances the ignition timing under light
throttle conditions, but on Turbo models, it will
retard the ignition timing when the
turbocharger is in operation.

Direct Ignition (Dl) system

The Direct Ignition system uses a separate

HT coil for each spark plug (see illustration).

The system electronic control unit (ECU)

monitors the engine by means of various
sensors, in order to determine the most
efficient ignition timing.

The components of the system are a

crankshaft position/speed sensor, ignition
cartridge with one coil per plug, diagnostic
socket, ECU, pressure sensor in the inlet
manifold (to determine engine load), knock
detector, and a solenoid valve (to regulate the
turbocharger operation).

During starting at a crankshaft speed in

excess of 150 rpm, HT sparks are triggered in
the cylinder pair with the pistons at TDC. Under
difficult conditions, multi-sparking occurs during
this period, to aid starting. The ECU determines
in which cylinder combustion is taking place by
monitoring the flow of current across the spark

plug electrodes, and then uses this information

to determine the firing order.

When the engine starts, the ignition timing is

always set to 10° BTDC, and will remain at this
setting until the engine speed exceeds
850 rpm. The ECU will regulate the ignition

timing at engine speeds above 850 rpm.

When the ignition is switched off and the

engine stops, the main relay remains
operational for a further 6 seconds. During this
period, the Trionic control module earths all
the trigger leads 210 times a second for
5 seconds, in order to burn off impurities from
the spark plug electrodes.

Because the system does not use any HT

leads, radio suppression must be incorporated
in the actual spark plugs, so resistor-type
plugs must always be used.

The Direct Ignition system uses the

capacitive discharge method of producing an
HT spark. Approximately 400 volts is stored in
a capacitor (see illustration), and at the time
of ignition, this voltage is discharged through
the primary circuit of the relevant coil.
Approximately 40 000 volts is induced in the

1.7 Direct Ignition cartridge

1 Transformer (12 volts/400 volts)

2 Capacitor 3 Ignition coil 4 Spark plug

1.13 Direct Ignition capacitor (arrowed)

located in the cartridge

HT secondary coil, and this is discharged
across the spark plug electrodes.

Should a fault occur in the system, a fault

code is stored in the ECU. This code can only
be accessed by a Saab dealer, using
dedicated equipment.

Note that the starter motor must never be

operated with the ignition cartridge
disconnected from the spark plugs but still
connected to the wiring loom. This can cause
irreversible damage to the cartridge.

Automatic Performance Control


All Turbo models are fitted with an

Automatic Performance Control system. The
APC system controls the turbo wastegage. If
pinking is detected, the APC system opens
the wastegate to reduce boost pressure, thus
eliminating the pinking. On models from 1989
the APC and Dl operations were control by the
one ECU. With this sytem, when pinking is
detected, the ignition timing and wastegate
position are adjusted. Refer to Chapter 4 for
more information.

Trionic ignition system

The Saab Trionic engine management

system uses the Direct Ignition and Automatic
Performance Control systems described
above, but integrated into its own ECU.

With the Trionic system, the spark plugs

themselves are used as knock sensors,

instead of employing a separate knock
detector in the cylinder block.

Ignition system 5B•3

Warning: Voltages produced by

an electronic ignition system are

considerably higher than those

produced by conventional ignition

systems. Extreme care must be taken
when working on the system with the
ignition switched on. Persons with
surgically-implanted cardiac pacemaker
devices should keep well clear of the
ignition circuits, components and test
equipment. Refer to the precautions in
Chapter 5A, Section 1 before starting
work. Always switch off the ignition before
disconnecting or connecting any
component, and when using a multi-meter
to check resistances.

Hall-effect ignition system

1 The components of the Hall-effect ignition
system are normally very reliable; most faults
are far more likely to be due to loose or dirty

connections, or to "tracking" of HT voltage
due to dirt, dampness or damaged insulation,

than to the failure of any of the system's

components. Always check all wiring

thoroughly before condemning an electrical

component, and work methodically to

eliminate all other possibilities before deciding
that a particular component is faulty.
2 The old practice of checking for a spark by
holding the live end of an HT lead a short

distance away from the engine is not
recommended; not only is there a high risk of
a powerful electric shock, but the HT coil or
amplifier unit may be damaged. Similarly,

never try to "diagnose" misfires by pulling off

one HT lead at a time.

Engine will not start

3 If the engine either will not turn over at all, or

only turns very slowly, check the battery and
starter motor. Connect a voltmeter across the
battery terminals (meter positive probe to
battery positive terminal). Disconnect the

ignition coil HT lead from the distributor cap,

and earth it. Note the voltage reading obtained

while turning over the engine on the starter for

(no more than) ten seconds. If the reading

obtained is less than approximately 9.5 volts,

first check the battery, starter motor and

charging system as described in Part A of this


4 If the engine turns over at normal speed but

wiII not start, check the HT circuit by
connecting a timing light (following its
manufacturer's instructions) and turning the

engine over on the starter motor; if the light

flashes, voltage is reaching the spark plugs, so

these should be checked first. If the light does

not flash, check the HT leads themselves,

follwed by the distributor cap, carbon brush

and rotor arm (see illustration),using the

inormation given in Chapter 1.

5 If there is a spark, check the fuel system for

faults, referring to Chapter 4A for further
6 If there is still no spark, check the voltage at

the ignition HT coil "+" terminal; it should be
the same as the battery voltage (ie, at least

11.7 volts). If the voltage at the coil is more

than 1 volt less than that at the battery, check
the feed from the battery until the fault is

7 If the feed to the HT coil is sound, check the
coil's primary and secondary winding
resistance as described later in this Chapter;
renew the coil if faulty, but be careful to check
carefully the condition of the LT connections

themselves before doing so, to ensure that the
fault is not due to dirty or poorly-fastened
8 If the HT coil is in good condition, the fault is

probably within the amplifier unit or Hall
generator circuit inside the distributor. Testing
of these components should be entrusted to a
Saab dealer.

Engine misfires

9 An irregular misfire suggests either a loose
connection or intermittent fault on the primary
circuit, or an HT lead fault.
10 With the ignition switched off, check
carefully through the system, ensuring that all
connections are clean and securely fastened.
11 Check that the HT coil, the distributor cap
and the HT leads are clean and dry. Check the
leads themselves and the spark plugs (by
substitution, if necessary), then check the
distributor cap, carbon brush and rotor arm as
described in Chapter 1.
12 Regular misfiring is almost certainly due to
a fault in the distributor cap, HT leads or spark
plugs. Use a timing light (paragraph 4 above)
to check whether HT voltage is present at all
13 If HT voltage is not present on any
particular lead, the fault will be in that lead, or
in the distributor cap. If HT is present on all
leads, the fault will be in the spark plugs;
check and renew them if there is any doubt
about their condition.
14 If no HT is present, check the HT coil; its
secondary windings may be breaking down
under load.

Direct Ignition system

15 If a fault appears in the Direct Ignition
system, first check that all wiring is secure and
in good condition. If necessary, individual
components of the Direct Ignition system may
be removed for visual investigation as
described later in this Chapter. Coils are best
checked by substituting a suspect one with a
known good coil, and checking if the misfire is
16 Due to the location of the spark plugs
beneath the Dl cartridge, it is not possible to
easily check the HT circuit for faults. Further

testing should be carried out by a Saab dealer,
who will have equipment to access fault codes
stored in the system ECU.

2.4 Rotor arm inside the distributor cap

3.1 Ignition coil located on the front



1 The ignition HT coil is located at the front of

the engine compartment, above the radiator
on the front crossmember (see illustration).
First roll back the rubber dust cover and
disconnect the HT lead.
2 Identify the low-tension leads for position,
then disconnect them from the terminals on
the coil.
3 Unscrew the mounting clamp bolts, and
remove the coil from the crossmember.


4 Testing of the coil is carried out using a
multi-meter set to its resistance function, to
check the primary (LT "+" to "-" terminals) and
secondary (LT "+" to HT lead terminal)
windings for continuity. Compare the results
obtained to those given in the Specifications
at the start of this Chapter. The resistance of
the coil windings will vary slightly according to
the coil temperature.


5 Refitting is a reversal of removal, but make
sure that the mounting clamp and coil are
thoroughly cleaned, and that the wiring
connectors are fitted correctly.

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