9.2. Check of system of ignition

Tension used in electronic systems of ignition is rather higher than tension, applied in usual systems of ignition. During the work with system at the included ignition it is necessary to observe extreme care. Persons with the implanted warm stimulator should steer clear of components of an electric chain in system of ignition and the test equipment.

Before connecting or disconnecting any of components, or to connect a tester for measurement of resistance always switch off ignition.

System of ignition with Hall's sensor

Components of system of ignition on Hall's effect usually are the highest degree reliable, usually malfunctions of system of ignition are connected with the easing or pollution of electric contacts or breakdowns of high voltage caused besides by pollution, the increased humidity or damage of isolation. Damages of components of system happen extremely seldom. Before pronouncing a final sentence any of system components, always carefully check fastenings of all wires and integrity of their isolation, working methodically, passing from one component of system to another.

It is not recommended to make check of spark plugs in the old way at which the electrode of a spark plug is brought on short distance to the engine block, it is connected not only with high risk of receiving electric shock, but also with a possibility of damage of high-voltage coils or the switchboard. Also never try to make diagnostics of the admission of ignition, disconnecting in turn high-voltage wires.

The engine is not started


1. If the engine either does not rotate absolutely, or is turned very slowly, check the battery and a starter. Connect the voltmeter to battery plugs (the positive probe of the measuring instrument to the positive plug of the battery). Connect a high-voltage wire of the coil of ignition from a cover of the distributor and ground it. Record indications of the voltmeter at an engine provorachivaniye a starter during time no more than 10 seconds. If indications less than about 9.5 In, first of all check the battery, a starter and system of a charge (see the Head Sistemy of start and a charge).
2. If the engine rotates with normal turns, but is not started, check a high-voltage contour by connection of a stroboscope (following instructions of the manufacturer) and an engine provorachivaniye a starter; if the stroboscope flashes, then it means that tension moves on spark plugs and it is necessary to check candles first of all. If it does not light up, check high-voltage wires, then a distributor cover, coal brushes and the runner (see the Head Routine maintenance.
3. If spark plugs generate a normal spark, check serviceability of fuel system (see the Head Toplivnaya and exhaust systems).
4. If there is no spark, check the positive plug of the high-voltage coil of ignition; on it there has to be same tension, as on the battery (i.e. at least 11.7 B). If tension on the coil more, than 1 V less, than on the battery, check a contour of power supply from the battery to the place of failure detection.
5. If power supply of the high-voltage coil of ignition as it should be, take measurement of resistance of primary and secondary windings of the coil of ignition
(see below in this Chapter); if the coil is faulty, replace it, however before it carefully check a condition of low-voltage electric contacts with the purpose to make sure that malfunction is not caused by their bad fastening.
6. If the high-voltage coil is in good shape, malfunction, perhaps, is in the block of the switchboard or in a contour of the sensor of Hall in the distributor. Check of these components has to be made in representative office of SAAB.

Admissions of ignition in the engine

Irregular admissions of ignition are usually connected or with bad contacts, or with interruptions in primary contour, or with damage of high-voltage wires.


1. After switching off of ignition carefully check system, having made sure that all contacts are pure and are reliably fixed.
2. Make sure that the high-voltage coil of ignition, the cover of the distributor and high-voltage wires are pure and dry. Check wires and spark plugs (by their replacement if necessary), then check a distributor cover, coal brushes and the runner (see the Head Routine maintenance).
3. Regular admissions of ignition are almost for certain connected with malfunctions of a cover of the distributor, high-voltage wires or spark plugs. For check of presence of high-voltage tension on all wires use a stroboscope.
4. If on any of wires there is no high-voltage tension that, or there is a damage of the wire, or there is a malfunction in a distributor cover. If tension is present at all wires, malfunction is in spark plugs; examine spark plugs and at the slightest doubts in the relation of their state - replace candles.
5. If high-voltage tension is absent, check the ignition coil; the break in its secondary winding can result from influence of loadings.

System of direct ignition (DI)

If in the DI system malfunction appeared, first of all check a state and reliability of fastening of all wires. If necessary separate components of system for visual survey can be removed. Coils of ignition can be checked by replacement of the suspicious coil by obviously serviceable.

As spark plugs are located under the ignition block, it is not so simple to make check of a high-voltage contour. Further checks have to be made in representative office of SAAB having the corresponding equipment for reading of codes of the malfunctions which are written down in the electronic actuation device of system.