Mechanics

COIL PACK

2004 Renault Clio

Engine Performance problem
2004 Renault Clio 4 cyl Front Wheel Drive Manual 42000 miles

hi could anyone tell me how to test a coil pack many thanks
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Bean172
January 27, 2009.



Is it a coils pack or COP. To check a coil pack. Check you have a hot/live feed to it during cranking. If you have a hot feed and no spark @ plug then the coil pack is bad ! To check a COP (coil on plug). Start engine. Unplug each COP wire one by one. If the engine doesn't die (stall) when you remove the wire from any one of them the COP is bad !

Coil Pack
A coil in a coil pack is turned on (for example is coil charging) by the PCM, and is turned off when firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the order is reversed. The next pair of spark plugs fire according to the engine firing order.

Coil On Plug
The coil on plug (COP) ignition operates similar to standard coil pack ignition except each plug has one coil per plug. COP has three different modes of operation: engine crank, engine running, and CMP Failure Mode Effects Management (FMEM).
Engine Crank/Engine Running
During engine crank the PCM will fire two spark plugs simultaneously. Of the two plugs simultaneously fired one will be under compression the other will be on the exhaust stroke. Both plugs will fire until camshaft position is identified by a successful camshaft position sensor signal. Once camshaft position is identified, only the cylinder under compression will be fired.

Dave H
Jan 27, 2009.