Misfiring mystery
The owner of this 2005 Ford Focus was pretty handy with the spanners and owned an EOBD code reader. When the car developed a misfire and the EML illuminated, he used his reader to find the code ‘P2303 Ignition Coil ‘B’ Primary Control Circuit Low’, then bought a new coil pack. This fixed the problem for three weeks, after which it reoccurred. Suspecting that he may have fitted a faulty coil pack, he asked us to take a look.
The problem was that code ‘P2303’ indicates a problem in the primary circuit – this might not necessarily be in the coil pack, but the wiring loom. An inspection of the loom revealed a nick which had exposed the wire, allowing the cable to corrode and weaken.
The new plug comes with a complete loom at just over £132. Our more economical answer was to source a plug from a breakers and solder the wire into position.