Yaris Mil Light On

[Buffys mum]

Hello to all. Hope someone can help with some advice. We bought a 1999 Yaris 5 days ago which has only 38K miles on the clock. It had a full Mr T service at 30K in 2005 so has been almost on holiday since then! We've given her an oil change and a new Halford's air filter (haven't replaced the oil filter yet as we can't get it off..). Yesterday we noticed the engine MIL light has come on and we can't fathom why. She's running perfectly well, no funny noises and not doing anything suspicious - does anyone have any idea what could have caused this? All the book says is to take it to a dealer.

Also, we have a Gemini alarm on her - does anyone know whether we can take the Battery out without risking the system locking us out or setting off the alarm?? We thought we could do a 'system re-boot' to try to clear the MIL???

Anyone out there who can help at all?? Thanks!

[alfiejts]

Sorry to see no one's replied to you as a new member on the forum...

The first step would be to try and find someone with a code reader to read the error code that will help you diagnose the fault.

I have one, but suspect I'm too far away....

You could buy one from eBay for £15 people say or at worst, find a local garage who will just read the error code and reset it.

There is at least one "common" issue with older Yaris's - its error code P1071 and its caused by a dirty or faulty MAF sensor inside the air-filter intake box.

If you do a search on the forums there are guides to cleaning them, but firstly you really need to know what the error code is....

There's no point just trying to reset the MIL, as it will just come on again (I know cos I tried this too)....

If you end up looking for the error code readers yourself, its an "ODB II" compatible unit you want and the socket is in the driver's footwell....

[gar]

Sorry to see no one's replied to you as a new member on the forum...

The first step would be to try and find someone with a code reader to read the error code that will help you diagnose the fault.

I have one, but suspect I'm too far away....

You could buy one from ebay for £15 people say or at worst, find a local garage who will just read the error code and reset it.

There is at least one "common" issue with older Yaris's - its error code P1071 and its caused by a dirty or faulty MAF sensor inside the air-filter intake box.

If you do a search on the forums there are guides to cleaning them, but firstly you really need to know what the error code is....

There's no point just trying to reset the MIL, as it will just come on again (I know cos I tried this too)....

If you end up looking for the error code readers yourself, its an "ODB II" compatible unit you want and the socket is in the driver's footwell....

Hi, you mentioned the socket in the drivers footwell... under the steering rack, or under the fusebox cover?

[alfiejts]

Sorry - I can't really remember exactly where as it was some years ago and the car's now gone....

The socket looks a bit like a "scart" socket on the back of a TV, so its hard to mistake.

I think I just looked underneath the dashboard in the driver's footwell, perhaps somewhere near the bonnet opening lever...

But I might not be right.....

[gar]

Ok, I will go take a looky! might help others too, if we can nail it down.

[Kcs]

My engine light comes on & off all the time (2000 x reg 1.0 vvti) read the engine code,and

it always comes uo PO172 system to rich bank 1 ! runs perfect with light on so i just let it do

its thing, or plug in OBD11 and turn it off myself, bank 1 must be the first o2 senser, which i

think is a bit over sensitive to un-burnt fuel !

[MEP's Yaris GS]

My engine light comes on & off all the time (2000 x reg 1.0 vvti) read the engine code,and

it always comes uo PO172 system to rich bank 1 ! runs perfect with light on so i just let it do

its thing, or plug in OBD11 and turn it off myself, bank 1 must be the first o2 senser, which i

think is a bit over sensitive to un-burnt fuel !

You need to change the sensor then. Lambda's are a serivceable part that don't last forever. It's reaction toulerances change, which causes the MIL light in your case to come on.

[HowardL]

Diverting away from the more urgent part of the post...

The OP says he cant get the oil filter off,

this seem to be getting more common, I too had a very tight filter and was getting desperate as it was just crumbling to bits as I tried to undo it

eventually it came undone, why do they put them on so tightly?

[joker69]

same thing happened to my moms yaris.

all of a sudden her engine light came on as well. we took the car in to a toyota dealership.

the dude said it came on due to a sensor in the catalytic converter, and he said not to worry about it, it would be too pricey to replace it but he restarted the sytem to turn the light off, and the light came back the DAY after.

this was about 3 years ago, no problems what so ever, just a fried sensor.

[Kcs]

Hi, have you changed yours yet ? i have 74k on the clock from new and running well,

did you buy a toyota o2 sesor or a aspurious one ? and how much are they ? my Dad

picked up a copy o2 sensor for his Rav but it was more sensitive than the old one he

took off !

Cheers

Kcs

My engine light comes on & off all the time (2000 x reg 1.0 vvti) read the engine code,and

it always comes uo PO172 system to rich bank 1 ! runs perfect with light on so i just let it do

its thing, or plug in OBD11 and turn it off myself, bank 1 must be the first o2 senser, which i

think is a bit over sensitive to un-burnt fuel !

You need to change the sensor then. Lambda's are a serivceable part that don't last forever. It's reaction toulerances change, which causes the MIL light in your case to come on.