Ford Ka engine light

[Stuw84]

Hi sorry another topic from me again. After being unable to remove the stuck sump plug on my wife's Ka I did the rest of the service anyway (air, pollen & fuel filters and spark plugs). I cleaned inside the HT leads and coated with silicone grease as per the manual and noticed the battery connections looked pretty bad so took them off cleaned them up. The car runs fine but the engine light is now on. The car has done nearly 120 miles since and its still on. Any ideas what could have caused it?

[john2443]

Stuw84 said:

Hi sorry another topic from me again. After being unable to remove the stuck sump plug on my wife's Ka I did the rest of the service anyway (air, pollen & fuel filters and spark plugs). I cleaned inside the HT leads and coated with silicone grease as per the manual and noticed the battery connections looked pretty bad so took them off cleaned them up. The car runs fine but the engine light is now on. The car has done nearly 120 miles since and its still on. Any ideas what could have caused it?

What caused it? Probably taking the battery connections off

How many wires went to the battery terminals? There may be more than the thick one to each terminal, are you sure you put them all back/ are the ring terminals still firmly crimped on / have you pulled the other end off somewhere?

[Stuw84]

All the leads were firmly put back on the terminals only disconnected each lead from the battery and cleaned it till I could see the metal again. In the Haynes manual it said the ECU should "re-learn" after disconnecting the battery? Its been driven 120 miles on varying roads now and seems to run perfectly fine?
I replaced a battery on my own car a few weeks ago and it caused no problems.

[Nick1point9]

There's no point trying to work out why the light is on by any means other than scanning it to check what code has brought to light on. Otherwise you're just stabbing in the dark.

[davepoth]

Nick1point9 said:

There's no point trying to work out why the light is on by any means other than scanning it to check what code has brought to light on. Otherwise you're just stabbing in the dark.

Yup, it won't be anything awful (it would have blown up already if it is) so plugging in is the easy answer. If you've got a smartphone you can get a bluetooth OBDII dongle thing off eBay, and an app to read and clear the fault codes for about £10 all in.

[ch427]

my guess is its logged a missfire, how much grease did you put on the ht leads?

[andyiley]

Pardon me for my ignorance as I ma not familiar with the ka precisely, but how do you clean "inside the HT leads" surely these are sealed??? I don't think I have ever come across any that aren't.

Also where exactly did you put silicone grease?

I can only assume you mean you cleaned inside the plug caps and smeared grease over the rubber cap seals.

Either way I think you need to listen to the comment above by Nick1point9 and simply get the engine codes read & reset, it only normally costs around £20 & takes 10 minutes at your local garage.

[Pumaracing]

Same thing happened to my Focus once many years ago. The ecu had logged a low battery voltage warning code during the battery change and it took days before the light went out but it eventually did by itself so I wouldn't worry. Give it a week or so.

[annodomini2]

Pumaracing said:

Same thing happened to my Focus once many years ago. The ecu had logged a low battery voltage warning code during the battery change and it took days before the light went out but it eventually did by itself so I wouldn't worry. Give it a week or so.

If it's that, start the engine, drive the car round the block, stop, ignition off, repeat.

10 times or until the light goes out usually does it.

[Stuw84]

Thought I'd update this again for anyone searching the web with a similiar problem. Had the car read on a proper scanner and it picked up that both lambda sensor failed and intermittment coolant sensor. The coolant sensor was a half a year old and had come with a cheap thermostat housing from ebay I fitted earlier in the year so replaced the sensor with a delphi one and the lambda with Ngk part. Was a bit annoying the coolant sensor failed so early on the cheap housing but the whole housing/thermostat was still £60 cheaper than the ford one and the replacement sensor only £10.
The car runs perfect now and even seems more economical. The engine light did stay on after the new parts were fitted however after I think about 5 starts it went out on its own.