Malfunction Indicator Lamp (MIL)

Sully

Hey,

Question for you car guys. Driving a Toyota Avensis, 03, and suddenly a warning light has came on when the engine is started. The warning is the Malfunction Indicator Lamp (MIL). I have no idea what could have caused this, it happened sometime day when we had a fairly heavy load in an attached trailer. It was when we had emptied the load and were returning home did we spot the light - and I don't think it was there earlier.

The last engine work I did was last night. I checked the Oil, and filled up the Washer with more water and cleaning solution for the spray which I bought in Tesco. I drove it home, and I am sure the symbol wasnt lighting. Nor was it earlier on today, but as the day went on it came up.

I know it says to bring it to the dealer, but what could have caused the problem? Can I continue to drive it or should it be attended to immediately? Any advise appreciated!

Cheers

crosstownk

The prudent thing to do would be to have it looked at by a Toyota dealer. What symbol was displayed when the light came on?

FredsWebHead

Hey Sully,
Just spotted this on the main page, thought I should put my tuppence in.
MIL or engine light on the dash lighting up is caused by a fault with the car.
There are many sensors around the car sending signal back to a central computer. If these signal are within spec no light shows up on the dash. If these signals are incorrect or not present theres something wrong somewhere with the car so it turns on the light on the dash.

Seeing as this problem showed up after you pulled a trailer, I wonder would it have something to do at the rear of the car.
First thing first would to find out if the fault is real. One way of doing this would be to disconnect the + lead of the battery for 30sec or so to in affect reset the pc with the car or ECU. This will wipe preset stations on the radio and reset the clock. When all is connected back the light should be gone when you restart the car. But if the fault is real the light will come back on after a couple of miles. Then its time to find out what the fault is, which means getting the fault code from the ECU. Don't know how much it is to get the fault code read. I have my own DIY OBD scanner. But then its a matter for the mechanic you use/dealership/or yourself if your handy enough with cars.
Hope I helped.
Fred.

colm_mcm

Is this an ECU light?

Sully

This is the symbol:-
http://i17.photobucket.com/albums/b69/SilverW0lf/Other%20Cars/light.jpg

Ill try persaude the father, who owns the car, to get it looked at. So far, he doesnt seem to pushed!

E92

Get it seen to immediately. It could be something very minor, or it could be very serious indeed. It's very hard to know, there are so many things that could get that light on from faulty ECU or O2 sensor to the light simply needing to be reset, the list is huge. The owners manual of the Avensis tells you to take it to a Toyota dealer immediately for a reason!

Sully

Fair enough.. Nobody seems to know what it means, I guess the warning is a vague one?!

FredsWebHead

Sorry sully,
I was away from the pc.
Yep thats the engine light or MIL. It's just a indicator light to tell you that there is a fault stored on the ECU. There is no way of finding out what the fault is unless you connect up a laptop to the car to retrieve the fault code. Hence why you have to bring it to a dealership or mechanic who has the right equipment. There are other basic ways of finding out like connecting up a light bulb to certain connectors in the fuse box and count how many times it lights up. Like i said it's basic. Did you disconnect the battery for 30secs to see if it lights up again?
Fred.

Sully

Dont suppose I can find this out myself (the code) or find out from a general mechanic?

nc19

i would say it most likely either an O2 sensor or the Cat. Both give problems on the avensis. This is not the type of fault I would recomend trying to fix on the cheap. If you get it to a toyota dealer and it is one these faults you may even get goodwill warrenty from toyota. i know of 2 7yr old yaris that got engines on goodwill

Oilrig

Sully!

Will you read FredsWebHead's advice and disconnect the battery first.

Step 1...

To my semi educated brain it would seem like he knows what he's talking about. ie good advice.

FredsWebHead

Just thought i would add abit more to the tread in case people might want to know more about car codes and sensor around the car. Now I'm still in the reading stages (so feel free to correct me if I'm wrong) and there is alot of material out there. First of all this is what I have.

http://cgi.ebay.ie/Diagnostic-Interface-Fault-USB-ISO-9141-Tool-ELM323-ELM_W0QQitemZ290201479370QQihZ019QQcategoryZ30921QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

And there is a link on that page that will send you sites where you can download the free software. Connect up the elm323 to the laptop then to the car. The connecter within the car is by law within 3 feet of the driver. Run the software it should tell you knonw to turn on your car cause it cant read anything. Just turn on the car not starting the engine and run the software again to read the ECU (PC within the car).
Now this works on my car (01 Lexus) I have disconnected a MAF sensor onthe engine to see what error it would throw up on the laptop. It threw up a P0 code like P0345 which when you search by google should throw up MAF sensor out of limits. Reconnected the sensor and then you can either reset the light on the dash by the software or you can leave will alone cause the ECU will check all sensor and if all is ok it should reset the light on the dash after a few miles. This also works on my fathers Avensis (01) but not on my wife's '99 avensis, this is because i need to send a command to the ECU to communicate tot he laptop which I'm still reading up on. This all might look simple to some of you. BUT beware I have read on some forums that people have had erased the ECU which means replacing it costing in the region of €500 to €1500, SO KNOW WHAT YOU ARE DOING......WARNING.
I'm here all day.
Fred.

Sully

Bringing the car to the mechanic on Monday all going to plan.

Rather not go resetting the PC just yet!

Thanks for your help, Ill keep you posted!

Sully

Toyota dealer said it was probably nothing to worry about and they are "finiky". As said, it needs to be connected to a computer to find the error. A local mechanic here said he will do it for us, so ill be arranging that with him tommrow.

FredsWebHead

Good to hear that it mightened be anything serious. Still get it least read. Post the reasults up here so we can figure out a solution.
Fred.

Sully

Mechanic had a look at it today, the error is to do with the oxygen sensor? You will have to excuse me, I am not into cars much and the description he gave me was thats its down to imissions and he needs to find out which sensor (or something to do with it anyway) is gone - and he will ask the Toyota Dealer in town. Apparently, it would cause the NCT to fail. So, should have it properly fixed within the few days.

FredsWebHead

Yeah, It happens alright. There is a couple of sensors on the exhaust usually before and after the cat. It measures the emissions of the exhaust fumes. It knows then if the car is running rich (burning more petrol than it should be) or running lean (burning less fuel than it should be). Its a good way to make the car run as efficient as it should. Seeing as the mechanic knows that the sensor is at fault and its a oxygen sensor it should cost at around €30 here

http://search.ebay.co.uk/oxygen-sensor_W0QQ_trksidZm37QQdfspZ1QQfromZR40QQfsooZ2QQfsopZ32QQlredZoxygenQ20sensor

But its more than likely the mechanic will go to the dealership and pay way over the odds. In sayin' that he wants to make sure he's putting in the right part for you. Has the meach. given you a quote yet?

Sully

So I take it the car should be burning more / less petrol then normal while the problem is there?

He said he is just asking them about which sensor is gone and he will either have the replacement himself or get it somewhere else. He normally isn't that expensive, but Dad gives him a good bit of work. No quote.

He looked at the breaks (they were acting oddly when I braked, mainly sudden breaking to slow the car down (not instant stop)) and said he wasn't able to replace the bulb for one of the knobs for the heating. Said the panel would need to be taken of and he wasn't sure he had the bulb for it.

Sully

Mechanic has taken it for the night, and will hopefully have it fixed when it arrives back in the morning

Sully

All fixed. Turned out to be a wiring issue!

Thanks for all your help, appreciated!

Sully

... and im back. Light went again a few weeks ago. Been pretty busy but the mechanic is collecting it on Monday evening to see what the problem is.

Frustrating!

WHITE_P

Check out the following.

http://www.ecufix.com/shop/index.php?main_page=index&cPath=69

FredsWebHead

Hey Sully,
I see the MIL is back on again,
Did your father bring the car to the mechanic yet.
If known can you post the DTC (diagnostic trouble code) here if you can.
Thxs.

AMurphy

A simple code reader will work. Just read the "P" codes. and relay.

Fred and White seem to know the drill, True it could be wiring... but lets assume it is not for the moment.

99 times out of 100 it's a sensor not the ECU, so if given a "bad ECU" diagnosis, seek a 2nd opinion... and it it is not actually stalling on the road, blowing smoke and steam...runing rough, failing to start, chances are it's a simple sensor or adjustment.

Sully

Okay the mechanic only got around to taking it today and came back. Apparently the catalytic converter is gone and its going to cost 1,000euro to replace! Im a bit supprised it was never spotted the first time and I think its a strange considence the MIL comes on so soon after the first check. Also, I have not found the car to be sluggish or acting anyway differently in recent months..

Sully

WHITE_P wrote: »

Check out the following.

http://www.ecufix.com/shop/index.php?main_page=index&cPath=69

Expensive but id say they would come in pretty handy!

Sully

Im curious as to how the catalytic converter would be gone if the car is showing no strange symptoms apart from the MIL light (its now off, but he said it will come back again). When my sisters went, her car broke down on the side of the road!

WHITE_P

Sully wrote: »

Expensive but id say they would come in pretty handy!

Depends on which one you buy £29.99 to £94.99 isn't exactly expensive if you don't have to go to a dealer / mechanic every time a fault light comes on.

Sully

Light came on again, as the mechanic said it would.

FredsWebHead

Hey Sully,
Did the mechanic tell you what code is coming up?
How many miles has te car done. Converters can be expensive,
Could be the sensor thats at fault too, broken wire, or damaged itself.
Butter,
Fred.

Sully

Nope, wasnt told the error code. There are 80k+ miles up on the car.