RAM 2500 Van V8-5.9L VIN Z LDC (2000)
Ignition Relay: Description and Operation
IGNITION SYSTEM
The ignition Systems used on the 3.9L V-6, the 5.2L V-8 and the 5.9L V-8 are basically identical.
The ignition system is controlled by the Powertrain Control Module (PCM) on all engines.
The ignition system consists of:
-
Spark Plugs
-
Ignition Coil
-
Secondary Ignition Cables
-
Distributor (contains rotor and Camshaft Position Sensor)
-
Powertrain Control Module (PCM)
-
Crankshaft Position, Camshaft Position, Throttle Position and MAP Sensors
DISTRIBUTOR
Distributor And Camshaft Position Sensor
All 3.9L/5.2L/5.9L engines are equipped with a camshaft driven mechanical distributor containing a shaft driven distributor rotor. All distributors
are equipped with an internal camshaft position (fuel sync) sensor.
The Camshaft Position Sensor provides fuel injection synchronization and cylinder identification.
The distributor does not have built in centrifugal or vacuum assisted advance. Base ignition timing and all timing advance is controlled by the
Powertrain Control Module (PCM). Because ignition timing is controlled by the PCM, base ignition timing is not adjustable.
The distributor is held to the engine in the conventional method using a holddown clamp and bolt. Although the distributor can be rotated, it will
have no effect on ignition timing.
All distributors contain an internal oil seal that prevents oil from entering the distributor housing. The seal is not serviceable.
SPARK PLUGS
Resistor type spark plugs are used.
Spark plug resistance values range from 6000 to 20,000 ohms (when checked with at least a 1000 volt spark plug tester). Do not use an ohmmeter
to check the resistance values of the spark plugs. Inaccurate readings will result.
To prevent possible pre-ignition and/or mechanical engine damage, the correct type/heat range/number spark plug must be used.
Always use the recommended torque when tightening spark plugs. Incorrect torque can distort the spark plug and change plug gap. It can also pull
the plug threads and do possible damage to both the spark plug and the cylinder head.
Remove the spark plugs and examine them for burned electrodes and fouled, cracked or broken porcelain insulators. Keep plugs arranged in the
order in which they were removed from the engine. A single plug displaying an abnormal condition indicates that a problem exists in the
corresponding cylinder. Replace spark plugs at the intervals recommended.
