'Check' Amber engine warning light

kuepper

This warning light in my Kia Picanto came on about 2 months ago and I went straight to a garage who said first let's try a reset and see if it comes back on. No sign of it since until yesterday when it came on again. Today I just started the engine and the warning light went out and hasn't come on again. Does this mean a sensor needs replacing? I'm worried about causing serious damage to the car if I carry on driving as I can't trust the warning light but what could a garage do if there's no warning light on to diagnose?

mgfvvc

Modern engine management systems save the code so, even if the light goes out, it will have a record until the storage is cleared. I had this with a Peugeot 207 recently and the Peugeot specialist was still able to diagnose the issue and replace a sensor.

NSG666

I had this with several different cars and vans over the years. A code will be stored but often turning the ignition off and on will put the light out. I've always worked on the basis that if the fault is serious/continuous then the light will stay on and there's usually another red light comes on if you have to stop using the car immediately.

That's not a recommendation just what I have done over the years without issue and you might want to check the handbook for your car.

AdrianC

Some faults are transient, and codes/light won't be stored across ignition off/on, unless the fault is detected again.

Some are permanent, and codes/light will be stored until cleared.

The only way to find out what it is is to read the codes. Anything else is guessing. Code readers are very, VERY cheap - less than a tenner plus a free phone app.

kuepper

It's been diagnosed as faulty camshaft sensor and been quoted £95 fitted inc vat

Goudy

Hopefully that's the problem, but it's worth mentioning a fault recorded by a sensor isn't necessarily a faulty sensor.
It could be the sensor is working and actually reading a fault with the cam position.

I write this as it's very common for garages to drive straight in and swap the sensor first in hope, then if the problem doesn't go away, investigate further.

It's a shame they do this, but sometimes the diagnostic tool they use don't quite delve deep enough to get enough information or they misread the meaning of the code.

Generally codes that relate to open/shorted circuits are broken sensors or wiring issues.
Codes that relate to above/below tolerance often means the sensor is really reading a problem.

It's not uncommon to get cam and crank sensor faults when the cam belt is old and a little stretched, or the belt has been replaced and the new position needs relearning/resetting or the cam phase variator/solenoid has a problem.

kuepper

Goudy said:

Hopefully that's the problem, but it's worth mentioning a fault recorded by a sensor isn't necessarily a faulty sensor.
It could be the sensor is working and actually reading a fault with the cam position.

I write this as it's very common for garages to drive straight in and swap the sensor first in hope, then if the problem doesn't go away, investigate further.

It's a shame they do this, but sometimes the diagnostic tool they use don't quite delve deep enough to get enough information or they misread the meaning of the code.

Generally codes that relate to open/shorted circuits are broken sensors or wiring issues.
Codes that relate to above/below tolerance often means the sensor is really reading a problem.

It's not uncommon to get cam and crank sensor faults when the cam belt is old and a little stretched, or the belt has been replaced and the new position needs relearning/resetting or the cam phase variator/solenoid has a problem.

The cam belt was replaced just before the first warning light occurrence 2+ months ago when a garage reset it and the warning light hadn't come on again until last weekend, so presumably it would have come on again before then if the cam belt needed adjusting? Now the sensor is being replaced if it comes on again I suppose at least I'll be armed with that info so thanks

Goudy

I've had a couple of cars that have needed a "phonic wheel relearn" after a cam belt change.
That's unlikely to be the correct term, but that's what everyone calls it.

What tended to happen is the old belt would have stretched a little and the ECU via the cam and crank sensors would have adjusted for it.
So when the new, tighter belt went on and the car started the cam and crank positions are now suddenly slighlty different so the ECU needed to be told to relearn the positions again, otherwise it threw a crank/cam related code when ran.

The relearn is usually done via the manufacturers diagnotic system, but I know with most Fiat/Alfa's you can force it by reving to 5000rpm for a few seconds, letting it idle for a few seconds (repeat 3 or 4 times) before switching of the igntion and restarting.

I'm not up with Kia's, but you might find some more info searching around the Kia forums.

Who replaced the belt? A Kia Dealer or indie.
Does the car run ok?

kuepper

Goudy said:

Who replaced the belt? A Kia Dealer or indie.
Does the car run ok?

indie. car runs fine. hopefully it was the sensor but i'll remember what you've desribed if it happens again

[Deleted User]

That light is a scam, mine came on all the time but when I looked under the bonnet the engine was still there.

Richard53

[Deleted User] said:

That light is a scam, mine came on all the time but when I looked under the bonnet the engine was still there.

Oh, is that what they mean when they say the engine is 'missing'?