Sign in to follow this  
dave_speak

Engine Light On..

Recommended Posts

Hi Guys,

I'm looking for some advice on sensor fault on my 03 Corolla 1.6VVti and would very much appreciate you comments.

I bought my Corolla about four years ago and have enjoyed trouble free driving for that time, its always guzzelled petrol and had an irratic tick over but thought it was just a characteristic of the car until the fuel comsumption became a bit of an issue.

I started the car one morning to find the engine management light came on after a couple of seconds running from cold. I checked all the forums for possible causes which lead me to the idle control valve, I cleaned to valve but with not results, then the MAF sensor which dramatically reduced the fuel comsumption but did not cure the fault.

I took the car to a garage for diagnostics and they said it reported an idle control valve fault but I'm not convinced. Since cleaning the MAF sensor it has changed how the engine runs and has now narrowed down the fault to cold starting.

The engine light may have gone out with regular driving then:

When the engine is started from cold there is little ( or appears to be) choke for cold running around 900 rpm which may be me messing with the control valve, then when the enging is at temperature and the engine idles..it firstly dips down as if to idle correctly around 700 rpm and then shoots up to 1200 rpm and fluctuates up & down +/- 200 rpm.

If I turn off the engine off when hot and restart the fault has gone, the idle perfect and fuel consumption good and after several uses the engines light goes out. Could this be a simple temp sensor fault or am I living in the past? :)

I have tried to remove the idle sensor completely to inspect it but its not coming off under any circumstances as it appears the screws have been glued, the bearings are a little sticky but still ok I think. The plugs were black and slightly worn when I took them out so changed them for new.

I read all the info in the manual and the MAF sensor values were all slight low at test temps but not drastically bad. I've been quoted some silly prices by the garage for repairs telling me its an 02 sensor fault, MAF sensor etc..

My car is only with very little now but theres loads of life left in it (80k miles) and I can't afford Toyota prices so if you could help it would be very much appreciated!!

Many thanks in advance,

Dave

P.S. Sorry if you've explained this a thousand times!

Share this post


Link to post
Share on other sites

Pre cat 02 sensor would be my guess. What fault code comes up?

Share this post


Link to post
Share on other sites

It made a massive difference on my car for the mot this week, new cat and oxygen sensor. It was running really rough and rich, down on power and high fuel consumption.

Share this post


Link to post
Share on other sites

Hi, many thanks for the replies,

I'm not sure what the fault code was as the guy at the garage was not the most willing lad I've come across! I was thinking it may have been the pre cat 02 sensor as I read an article in blog which seemed to fit with the systoms.

Not sure if its relevant but its been used around town all its life too so loads of stop starts.

I'll have a look for an 02 sensor and socket.

Thanks again for your time guys :)

Share this post


Link to post
Share on other sites

Hey,

Don't forget there are two 02 sensors, pre and post cat.

Thats why knowing the error code should help, I would not replace stuff on a whim.

See Euro Car Parts do both at a reasonable price, no idea what Toyota charge ?

Would only look at top qulaity brands anyway, from previous sensor problems on an Avensis cheapos can be more trouble than they are worth.

Same with a scrap yard, you have no idea of its condition, don't forget, never try to clean them, that can destroy them.

My 1.6 , when hot will hold at around 1200rpm for a few seconds before dropping to 700rpm.

Are you sure nothing is causing it to run up to 1200 again like air con or some heavy electrical usage coming on ?

Share this post


Link to post
Share on other sites

Post cat sensor will only trigger the ecu light if the emissions are high. Wont cause it to run ruff or anything even if it wasnt pluged in. Its just a warning light for the condition of the cat.

Hense if its running ruff itll be the pre cat one.

To the OP buy a cheep OBD11 code reader off ebay for £35. You can read the codes yourself then ;)

Share this post


Link to post
Share on other sites

Thanks for your posts guys,

The weird thing in all this is the car has just passed an MOT and really doesn't run rough! When the car is cold there is very a slight hesitation and the revs are fluctuating when nearly at operaing temp. I turn off the motor and restart and its running like a dream..never better.

If its possible for the O2 pre cat to be lazy I think it'll be my first port..I know its wrong to replace adhock but Toyota estimate £500 squids for the job! The Denso part is about £68 on ebay plus a tool for the job which I haven't found yet.

I'm trying not to let this spoil my experience of the car as I think its much better than BMW which I had an awful time with.

Best wishes, :)

Dave

Share this post


Link to post
Share on other sites

The weird thing in all this is the car has just passed an MOT The Denso part is about £68 on ebay plus a tool for the job which I haven't found yet.

Hi,

Steven252 - thanks for the sensor info, handy thing to know how they react.

Any suggestion if any of those countless ebay readers are better than the others ?

Dave_speak

Assume you mean a special tool to get the precat sensor out without removing the heat shield ?

with a 'proper' tool it looks like one slip and you could smash the brake pipes or rip the wires off the sensor.

Think I would prefer to remove the four bolts and lift the heat shield so you can get a good fitting spanner around the sensor flats.

Give them all a good soaking of penny fluid over night.

Share this post


Link to post
Share on other sites

Hi all.

I bought a Foxwell NT300 for £60.00 on fleabay. it's OBD II and Canbus compliant and works really well. I did look at the cheaper ones, but decided on the NT300 as it can be updated.

Used it on my Rolla, no faults detected (as expected) and on a couple of Civics (faults detected and cleared).

It gives you the fault code and tells you what the fault is.

When you consider how much it costs to have the fault diagnosed (£80.00 for my old Rover 214 12 years ago - and no I didn't take up the offer), it pays for itself very quicky.

Cheers

Share this post


Link to post
Share on other sites

Hi all.

I bought a Foxwell NT300 for £60.00 on fleabay. it's OBD II and Canbus compliant and works really well. I did look at the cheaper ones, but decided on the NT300 as it can be updated.

Used it on my Rolla, no faults detected (as expected) and on a couple of Civics (faults detected and cleared).

It gives you the fault code and tells you what the fault is.

When you consider how much it costs to have the fault diagnosed (£80.00 for my old Rover 214 12 years ago - and no I didn't take up the offer), it pays for itself very quicky.

Cheers

Hi,

Thanks for that, was looking on ebay last night and saw the very similar Autel MS509 at around £66 -also sold by Argos and Amazon.

Seems they both do CanBus which does make it more future proof. ( assume Uk Rollas do not have canbus? )

To me these more expensive checkers, with the live data screens seem to say you can monitor the signals of the sensors.

Am I right in thinking you could monitor and note the signal from the sensors now so that if something started to go wrong in future have a good reference point to work from ?

Also someone on Amazon saying the Autel one they bought proved to be a clone when he tried to register it with Autel.

Any hint of cloning with the Foxwell ; can you check its a good one with Foxwell ?

thanks

Share this post


Link to post
Share on other sites

I have a super dooper cheepo ebay one -

http://www.ebay.co.uk/itm/D900-Universal-OBD2-EOBD-CAN-Fault-Code-Reader-Scanner-diagnostic-scan-tool-/110877986674?pt=UK_Diagnostic_Tools_Equipment&hash=item19d0d7cf72#ht_2457wt_1008

Granted it doesnt do airbag or abs systems - but none under the £150 mark do anyway. It does everything you will need out of a code reader and for £30 it is REALLY well made. Ive droped mine several times (once into a bucket of Oil) and its still going strong after 2years. You can get the CD updates for them online, but unless your working on a newer car than it was made then theres not mich point really. I have used it on many cars saving friends and family a fortune, plus time diagnosing the fault. Its really easy to use and i would thougherly recommend it.

I do have access to a snap on nexus unit (all £2500 of it) as i used to work in a garage. However i havent come accross anything i cant do with my cheep one unless its abs/srs related so dont use it much.

Best £30 i spent for my tool box

Share this post


Link to post
Share on other sites

oldcodger.

I did have trouble registering my NT300, tried several times, then it eventually accepted it. It does indeed do live data reading and you can also record and play time lapse logs.

Take a peek at the link http://www.foxwelltech.com/NT300.html

This should answer any questions you may have.

Oh yes. What put me off some of the readers was the connect cable is built in, not removable (I prefer a removable cable for neat storage-fussy old git I am).

Any more Q's, let me know.

Share this post


Link to post
Share on other sites

Hi Guys,

Thanks for all that info, very helpful.

Have downloaded the manuals for the FoxWell and also the Autel MS509 , it would seem from the manuals diagrams / lcd layouts they are basically the same unit apart from the cosmetic styling.

Also found the Gendan one which they say is their own, but again seem too similar not to be the same.

It seemed a choice between them as I initially thought the D900 Steven mentioned was just a 'cheapo' reader, but after finally finding the manual it is a full 'scanner' providing live and freeze data.

The D900 s manual is a much shorter version but I think again it the same basic unit as the othes ?

All of them have that I/M readiness routine, which seems to be a USA thing, does it have any use on our cars ?

So think for my use at £30 the D900 seems the best buy.

Steven,

That ebay site you mentioned, Tool_bay, was it just one you picked out from the several that do the D900 or are they a place you can recommend over the others ?

thanks again

Share this post


Link to post
Share on other sites

Yes it does both live and freeze data. Its honestly a real good bit of kit for £30.

I dont know who i bought mine off as i bought it 2 years ago off ebay, id go for the cheepest one as tool sellers on ebay all seem pritty reliable in my experience.

Share this post


Link to post
Share on other sites

Yes it does both live and freeze data. Its honestly a real good bit of kit for £30.

I dont know who i bought mine off as i bought it 2 years ago off ebay, id go for the cheepest one as tool sellers on ebay all seem pritty reliable in my experience.

Hi,

Seems the 2012 model is around from £25 inc. but noticed the link you gave seemed to have dupilcate entries but in fact for £1 more then include another CD saying it contains the following.

However do not know exacly what comes on the scanners own CD other than the manual.

Does it look worthwhile to you or is most of it on the scanners cd anyway ?

plus free CD software with over 7000 DTC code finder, just type the code it will give code full definitions

Plus 160 common fault codes explain in detail & Possible Solutions

Inc : What does the code mean in detail , Symptoms , how the fault Causes and Possible Solutions

http://www.ebay.co.u...=item19d1591d09

Share this post


Link to post
Share on other sites

In all honesty i havent even used the CD that came with mine. It gives a brief description of the code on the hand held system anyway. Being a ex mechanic i kind of know what it means from past experience so havent had to check codes for more info as of yet. But for the sake of £1 id personally get one with the CD just incase :)

Share this post


Link to post
Share on other sites

Had a look on ebay for the scanner and it looks really good value..think I may invest in that as I've already paid Mr Happy £25 at the garage and no further forward!

Thanks!

Share this post


Link to post
Share on other sites

Hi,

Ordered one yesterday from that link Steven 252 mentions, will let you know how good the seller and reader are, hopefully arrive soon.

Share this post


Link to post
Share on other sites

Hi,

Received the D900 scanner in todays post, first class recorded.

As described in that strong fabric carry case plus 3 AA batteries so it can be run when not connected to the car.

Just given it a test out and its easy to use and does exactly as it says on the can.

Glad I got this over the simpler £20-£30 code only readers; with the D900s Live Data function I could see things like Coolant Temp, Maf and both Lambda sensor voltages.

I did not have any codes stored, so unable to see what info the reader gives to each error code, but doubt it will be as comprehensive as the lists that come with that extra CD I ordered for the extra £1.

Just wonder what data the other ebay sellesr provide as non of them seem to proved this extra.

This is the package I got http://www.ebay.co.u...ME:L:OC:GB:3160

The only thing I did find that although I did not clear or erase anything while connected to the car, on restart after the scanner was disconnected, it seems the ECU has gone back to a learn mode, noticed the tickover was hunting up and down between 500 -1000rpm, as when I disconnected the Battery one time, still it soon learns afer a few runs.

So thanks Steven252 you have really guided me to a great buy !

To anyone wondering why I got one when I have not had any trouble with the Rollas Check Light, on my old Avensis I had lots of trouble with lambda sensors and the check light comming on etc, all the time and money I went to trying to sort that, you would understand why having such a tool is very worthwhile as the orignal OP Dave_Speak has similary found out the hard way.

With this reader being CAN compatible it shoud be good for future cars as well.

Share this post


Link to post
Share on other sites

No problem :thumbsup:

As i said earlier, it does give a description with the code from the hand held device, i have yet to find one that its only provided the code and nothing else - hense not even using the CD yet.

Im not sure about the learning mode as i never noticed that with mine - i will check next time i use it :)

Im glad your happy with your purchase - i use mine all the time and its earnt more than its £30 keep :)

Share this post


Link to post
Share on other sites

Okay..its been a while since the last reply but thought I would write back with the solution!

I went to buy a new Denso pre-cat o2 sensor and have it fitted at the garage, instead of just fitting it the mechanic scanned the EMU and came back with another idle control valve fault and said there was nothing wrong with the o2 sensor, he cleared the fault and said to take off the valve & clean it.

The valve is a rotory type which I thought I had cleaned as per the YouTube vids not realising they were demonstrating the conical seat type..doh! When I tried to take the valve off the throttle body the screws would not budge even with the best snap-on toys. I then found a better YouTube tutorial that said to use and imapct hammer to get the off...yikes! (fitted a new gasket too..a good move for 3 quid!)

Anyway, this worked really well with virtually no brute force! sSure enough even though I thought I'd clean the valve it was sticking very badly and full of carbon. This is schematic was also included in the YouTube text and I found it very helpful..took me a whole night of searching with keywords to find it!

http://alflash.com.ua/idlet.htm

After cleaning the valve with carb cleaner and reassembling I thought I would carry out a test as per the diagram on the page before refitting, it worked really well one way (closing) then after reverse polling there was a bit of an "induction spark" and it consequently stopped working at all.

Two things here..Firstly the diagram says to "on vehicle test" so I used the car Battery for the power..I then noticed "V5.8" on the idle control motor..great!

Then secondly, the Denso motor was of a different type (although looked the same) to the diagram as described in the text but not the drawing, as it has no bi-metalic strip but has a permanent magnet instead, this one still has two direction coils for the valve direction but one is energised all the time, whatever it was that "popped" it didn't take kindly to me shoving 12v up a one way street and no longer worked at all and thus held the choke on even when at running temp.

I called Toyota about supplying a new motor and shortly after the paramedics arrived to save me..the cost..£420. A wreckers in Birmingham supplied me with a complete throttle body in very good nick (part number checked) for £60 and after fitting the new motor this morning the car is running like a dream..36-56 mpg..thank the lord!!

I just thought I would share this with you just incase anyone else maybe having a prob with there's dismantling the idle control sounds quite horrific with an impact driver but it was v easy and the car litteraly runnins like new now.

Thank you all very much for your time and input!! :thumbsup:

Dave

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this