Engine Management Light

[1bloke1dog1mr2]

Hi all. :D

Just topped up with petrol this morning and then half way to work the engine management light comes on. I've never seen this happen before, so I'm assuming it's not the petrol.

All other lights are off, I check the oil & water regularly and no problems there and the temp gauge was normal. I'm popping it in for a service Thursday, should I stop driving it til then? Nothing abnormal with the drive of it.

Thanks in advance for any suggestions.

[GIDDLEPIN]

The CEL lit up on mine not so long ago (before the contaminated petrol episode), the diagnostics didn’t show up anything and they did an ECU re-set (would have done it myself and saved £45 ) the only explanation they could give was that some dirty oil (nothing serious) had triggered one of the sensors, my car has been dealer serviced from new so it’s not as if an oil change was missed, that was about 2/3 months ago and so far everything has been ok.

Les

PS If your CEL ever flashes on and off...STOP and get it recovered ;)

[Chris.S]

It will be one of the oxygen sensors thats gone faulty

[GIDDLEPIN]

It will be one of the oxygen sensors thats gone faulty

If this is the case don't let them change it for silly money, check THIS out. I know it is for the Celica but ours are just the same ;)

Let us know how you get on

Les

[1bloke1dog1mr2]

It all comes at once with vehicles, our other car needs taxing and our bike needs it's insurance and MOT all this month

Thanks Les, very useful info there

Hopefully Toyota won't take it upon themselves to do the work without asking me first. Will certainly let you know how I get on....

[bgorman]

It all comes at once with vehicles, our other car needs taxing and our bike needs it's insurance and MOT all this month

Thanks Les, very useful info there

Hopefully Toyota won't take it upon themselves to do the work without asking me first. Will certainly let you know how I get on....

Hi, We had the same thing happen on our roadster last year, ie CEL light came on but no effect on performance, took it to Toyota dealer and we were told that it was a oxy sensor, so car was duly booked in for the following Saturday.

However, I happened to mention this to a man who does sport and rally car tuning and he said it was almost certainly just a dirty air flow (MAF) sensor He took out the sensor (two screws one connector ),and sure enough one of the two thermistors inside was covered in gunge. He sprayed it with carb cleaner and used a cotton bud to remove the gunge.

The sensor was then replaced and the light reset by dissconnecting the Battery pos for 1 second(this clears the light but will not effect the clock or radio settings).

This was last Sept and we have had no probs since having done 4000 mls.

This all took about 10 mins and cost nothing. He is convinced that 99% of CEL probs are caused by this in all makes of car, after all how many times do we see on TOC about people replacing oxy sensors only to have the problem return?

Our car had only done 36000 mls when this happened and air filter was spotless but it seems our case is quite common.

[1bloke1dog1mr2]

This all took about 10 mins and cost nothing. He is convinced that 99% of CEL probs are caused by this in all makes of car, after all how many times do we see on TOC about people replacing oxy sensors only to have the problem return?

Our car had only done 36000 mls when this happened and air filter was spotless but it seems our case is quite common.

Reading through various topics on TOC and others, it does seem to be a common problem. My roadster has only done 46K, and I was a bit concerned myself.

Will take my Hubby's car tomorrow so he can have a look at the MAF, it's definitely a good (and cheap) place to start. Where can this be found?

[bgorman]

This all took about 10 mins and cost nothing. He is convinced that 99% of CEL probs are caused by this in all makes of car, after all how many times do we see on TOC about people replacing oxy sensors only to have the problem return?

Our car had only done 36000 mls when this happened and air filter was spotless but it seems our case is quite common.

Reading through various topics on TOC and others, it does seem to be a common problem. My roadster has only done 46K, and I was a bit concerned myself.

Will take my Hubby's car tomorrow so he can have a look at the MAF, it's definitely a good (and cheap) place to start. Where can this be found?

The MAF is mounted in the air duct between the air filter and engine (dead easy to get to) it is held in with 2 screws and has a connector (push fit with a retaining clip).

I am certain that there is a very good article posted on TOC somewhere, I just cant remember where but someone out there might.

[bgorman]

This all took about 10 mins and cost nothing. He is convinced that 99% of CEL probs are caused by this in all makes of car, after all how many times do we see on TOC about people replacing oxy sensors only to have the problem return?

Our car had only done 36000 mls when this happened and air filter was spotless but it seems our case is quite common.

Reading through various topics on TOC and others, it does seem to be a common problem. My roadster has only done 46K, and I was a bit concerned myself.

Will take my Hubby's car tomorrow so he can have a look at the MAF, it's definitely a good (and cheap) place to start. Where can this be found?

The MAF is mounted in the air duct between the air filter and engine (dead easy to get to) it is held in with 2 screws and has a connector (push fit with a retaining clip).

I am certain that there is a very good article posted on TOC somewhere, I just cant remember where but someone out there might.

Try "cleaning maf" as search, there is one for the Lexus, but is very similar to the Toyota procedure.

[1bloke1dog1mr2]

Many thanks, you're a star. Fingers crossed that's the answer

[1bloke1dog1mr2]

Ok, update on the CEL light...

Hubby has cleaned the MAF sensor after you lovely lot told us where it was located. Job done in 15 minutes, reset the light....started engine, went for a drive....

NO LIGHT...YEY!!!!

Thanks for all the advice , and fingers crossed that it won't come on again.

As posted in General Discussions by J, this forum is ace! ;)

[bgorman]

Ok, update on the CEL light...

Hubby has cleaned the MAF sensor after you lovely lot told us where it was located. Job done in 15 minutes, reset the light....started engine, went for a drive....

NO LIGHT...YEY!!!!

Thanks for all the advice , and fingers crossed that it won't come on again.

As posted in General Discussions by J, this forum is ace! ;)

Very glad to have been of help, it just goes to show that you should not always take the word of "experts" as fact, not just with garages but with life in general, - but hey dont get me started on that one!!!

[Black Knight]

Unfortunately all diagnostics work done by dealers these days seems to be done based off the intelligent tester which is an definate oxymoron.

The ECU expects to see certain results from certain sensors under certain conditions. If it see's something it doesn't expect it throws a fault and puts a light on.

In this case the ECU is getting told it's getting X amount of air coming in and so it adds Y amount of fuel. The O2 sensor then checks the out put. When it reads something it doesn't expect it calls a fault which is unfortunatley not a constant fault

Dealer reads the manual and it gives possible fault and some spanner monkey changes the sensor. Problem goes away and therefore the problem is instantly "Definately an O2 sensor fault" no matter that they haven't checked wiring connections or air flow sensor (which also incidentally they would get paid very little for fixing, dependant on fault of course).

In recent years I've decided that a. if you find a dealer that actually knows ANYTHING about engines you're lucky B. dealers are robbing *****

[bgorman]

Unfortunately all diagnostics work done by dealers these days seems to be done based off the intelligent tester which is an definate oxymoron.

The ECU expects to see certain results from certain sensors under certain conditions. If it see's something it doesn't expect it throws a fault and puts a light on.

In this case the ECU is getting told it's getting X amount of air coming in and so it adds Y amount of fuel. The O2 sensor then checks the out put. When it reads something it doesn't expect it calls a fault which is unfortunatley not a constant fault

Dealer reads the manual and it gives possible fault and some spanner monkey changes the sensor. Problem goes away and therefore the problem is instantly "Definately an O2 sensor fault" no matter that they haven't checked wiring connections or air flow sensor (which also incidentally they would get paid very little for fixing, dependant on fault of course).

In recent years I've decided that a. if you find a dealer that actually knows ANYTHING about engines you're lucky B. dealers are robbing *****

Perfectly summed up!

[1bloke1dog1mr2]

*****ECU UPDATE*****

Hi all, since cleaning the MAF sensor all was ok, but the EML came back on after around 150/200 miles. SO, we cleaned it again... 40 miles later EML back on again.

Now I know there is something wrong, but I'm pretty sure it's not the MAF sensor. The performance of the car is fine, tick over is fine & fuel consumption is normal (at 87p a litre, £10 carries me approx 90 miles)

Any suggestions, apart from popping it in to Mr T for a diagnostic check? I don't want to start running it if there is going to be more expensive damage done like the cat etc... and is this acceptable for a car that's only covered 46k miles?

Also, can most reputable local garages do the diagnostic checks?

Thanks in advance

[cfc1]

Any garage that has a code reader can diagnose the fault... but they will charge extorsion rates (40 - 50 quid) for the 2 minute job of plugging their computer into it.

[GIDDLEPIN]

Sounds like it could be one of the O2 sensors, if it is DONT let them change it for silly money, check THIS thread out. The sensors are the same for our Two's and are VERY cheap.

So let us know

Les

[1bloke1dog1mr2]

So it's probably worth getting it checked then getting the relevant sensor on the internet and getting it fitted it at our local garage who are very reasonable & reliable?

Hoped it wouldn't be this xp, but will let you know how I get on.

Thanks guys.

[1bloke1dog1mr2]

Hi all,

Had the diagnostic test done this morning and everything is within their limits. Apparantly it mostly caused by dirty fuel (not here too!) and the ECU is v sensitive. So he's cleaned the system and I've got some stuff to put in with the fuel so hopefully that's sorted. Only thing he mentioned was it was a bit sloppy at around 2500 revs.

IF the EML comes on again he said it could be the pre-cat sensor, but let's hope that doesn't happen.

[GIDDLEPIN]

Fingers crossed that you don't see the light (not in the religious sense mind you ;) )

[1bloke1dog1mr2]

just one more thing, actually two (I promise! ;) )

1: When you pay for a diagnostic test, should you get a print out of the results? My Hubby took my car for me, but when I got home tonight all I have is a receipt for the cost of the test and Forte Gas treatment. I' guessing they think that if the EML comes on again we won't know which sensor needs replacing.

2: He said my car has two sensors, is this right? It's a 2000 x reg

As usual the garage said if we need a sensor they can order it (of cause they can) but of cause I'll be taking your advise Les, and ordering it ourselves.

Thanks again to everyone who has helped with this...I'll buy you all a drink down the pub!

[GIDDLEPIN]

not sure if they do printouts of diagnostic results, I've never had one on any of mine.

Your car has three sensors two before cat sensors. You can see where they are located in the picture (the two wires going into the heat shield bottom right).

The other one is the after cat sensor, if you look under the back of your car near the tail pipe you can see it there

[1bloke1dog1mr2]

Thanks Les,

that's what I thought. Perhaps I got the message wrong.

No more questions.... ;)

[1bloke1dog1mr2]

Changed the left O2 sensor & reset. Been for a spin and the EML is back on :o . I'm REALLY fed-up with this now. I was hoping that was the problem but the sensor that came out was quite clean.. just a bit greyed up but not coated in anything.

I haven't even been two trips and the lights on!!! :censor: What's going on?

[cfc1]

Best thing to do is take it to a garage with a code reader.. problem could be any number of things :(