I have a 57 plate cmax with a 2.0 zetec petrol engine and when I start driving the engine warning light comes on but doesn't affect performance. After about a week the engine light goes out until a couple of days later when it comes back on. any ideas what this could be?
30,000 miles on the clock
The light goes out after a number of engine starts without the problem, it will come on again when the problem has reoccured several times. So ergo you have an intermitant fault. Its worth buying a scanner as the garage will probably charge at least £50 to scan it for you, be sure to print off a report if you take it in to be rectified, if they are a decent garage they shouldnt charge for a rescan. It's also possible that you can rectify the problem yourself. I got my plug in scanner on Ebay for about £14 a year or so ago you can get the same item from the site now V1.5 USB ELM327 OBD2 OBDII CAN-BUS Auto Car Diagnostic Interface Scanner Tool PC | eBay for £10 inc post. They also offer stand alone units but these are more expensive and will only run with the software that they come with. With the connected to a computer type you can download other software and use it with them.
You can get a list of Ford ODBII codes from this site OBD-II Check Engine Light Trouble Codes. I also note that the link to Ebay from Happykfc20 offers the item for £10 sourced in the UK with a quicker delivery.