HOLDEN GEN III V8, Обучение по обслуживанию

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GEN III V8 ENGINE MANAGEMENT
IGNITION SYSTEM
The ignition system on the GEN III V8 engine features a multiple coil ignition and is known as coil near plug.
The spark plug leads are short compared with a distributor ignition system. Eight ignition coils/modules are
individually mounted above each cylinder on the rocker covers and fire sequentially. There is an Ignition Control
(1C) circuit for each ignition coil/module. The eight ignition control circuits are connected to the PCM. All timing
decisions are made by the PCM, which triggers each coil/module individually. Each ignition coil/module has a
power feed, an earth circuit and a reference low circuit.
Ignition System Overview
The electronic ignition system provides a spark to ignite the compressed air/fuel mixture at the correct time. To
provide optimum engine performance, fuel economy, and control of exhaust emissions, the PCM controls the
spark advance of the ignition system.
The electronic ignition system does not use the conventional distributor and coil. The ignition system consists of
the following components:
• Eight ignition coils/modules
• Eight Ignition Control (1C) circuits
• Camshaft Position (CMP) sensor
• 1 X Camshaft reluctor wheel
• Crankshaft Position (CKP) sensor
• 24X Crankshaft reluctor wheel
• Powertrain Control Module (PCM)
Ignition Coils
This system puts out very high ignition energy for plug firing. Because the spark plug leads are shorter, less
energy is lost to spark plug lead resistance. Also, since the firing is sequential, each coil has far more time to
saturate as opposed to the three in a waste spark arrangement. Furthermore, no energy is lost to the resistance
of a waste spark system. The ignition coil/modules are fused separately for each bank of the engine are
supplied with the following circuits:
• Ignition feed circuit • Ignition control circuit • Earth circuit • Reference low circuit
Circuits Affecting Ignition Control
To properly control ignition timing, the PCM relies on the following information:
• Mass Air Flow
• Engine Load (manifold pressure or vacuum)
• Atmospheric (Barometric) Pressure
• Engine Coolant Temperature
• Intake Air Temperature
• Throttle Position Sensor
• Crankshaft Position
• Engine Speed (RPM)
• Automatic Transmission Range from the Transmission Range switch.
The PCM is responsible for maintaining correct spark and fuel injection timing for all driving conditions. To
provide optimum driveability and emissions. The PCM calculates the desired spark advance from information
received from the sensors and triggers the appropriate ignition coil/modules at the desired time to provide the
spark advance needed.
Results Of Incorrect Operation
An ignition control circuit that is open, earthed, or short circuited will set an ignition control circuit DTC. If a fault
occurs in the 1C output circuit when the engine is running, the engine will experience a misfire. DTCs P0351-
P0358 will set when a malfunction is detected with an Ignition Control circuit.
If the engine cranks but will not run or immediately stalls, Engine Cranks But Will Not Run diagnostic table must
be used to determine if the failure is in the ignition system or the fuel system. If DTC P0341, P0342, P0343,
P0335, P0336 is set, the appropriate diagnostic trouble code table must be used for diagnosis.
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