First Problem with our MR2 - Engine Warning Light

[Skirmisheer]

Well we thought everything was going fine with our 2001 MR2. Until this afternoon that is when I noticed the Engine Warning Light was on. Everything else seems fine though and the engine feels as though everything is okay. This is the point I wonder about the wisdom of having a 10 year old toy where I suppose things like this are going to happen now and then.

So, can anyone advise what I should do and what could possibly be causing this warning light to come on?
I suspect I'll be advised to get a Fault Code Reader?

Any help gratefully appreciated.

Dave

[thetapeworm]

I'd be tempted to reset the ECU and see if the fault light comes back on before making any major investments.

[eybic]

What era is your MR2 from? If it is a mid/late nineties one then you can read the codes by bridging a couple of terminals in the diag socket, this can be done with a paperclip and the light will then flash a sequence to tell you what the issue/s is. Check elsewhere but I think you bridge "E1" and "TE1" (it's been years since I had a standard ecu so can't 100% remember the exact ports)

If it is one of the newer shape ones then I don't know.

[Skirmisheer]

It's a Mk3 2001 model so I don't think the paper clip method will work. I could be wrong though.

How can I do an ECU reset? Is it a battery disconnection process?

[japgt]

Disconnect the battery for 10 minutes or so, reconnect and should have reset, however, if you value your toy, i would go and get it diagnosed by a proper garage who specialises in that type of car, toyota dealer would prob be best suited for the diagnosis, but go elsewhere for the work to be done without paying main stealer prices.

[thetapeworm]

The common one seems to be a P0141 code which indicates that the 3rd O2 sensor is jiggered - P0135 seems to come up a lot though.

Any garage with an ODBC2 reader should be able to pull the code for you - then somewhere like http://www.mr2roc.org will probably help you to sort it out in the most cost effective way.

You might also be able to self diagnose with http://www.obd-codes.com/trouble_codes once you get the code(s).

[Skirmisheer]

Well I've also been on the MR2 forum and they've suggested I buy a code reader to diagnose the problem. They're only £18 and it will come in useful in the future I'm sure.

[trickywoo]

thetapeworm said:

The common one seems to be a P0141 code which indicates that the 3rd O2 sensor is jiggered

My first thought with an engine light but OK running was O2 sensor also. I've had experience.

Fault reader is the way to go to be sure. A friendly garage might not charge or only charge tea money.

[Skirmisheer]

Iv'e ordered a reader so that should diagnose the problem. I have also disconnected the battery which removed the warning light. It's not the answer I know but it will be interesting to see if and when it comes back on again.

[nottyash]

Skirmisheer said:

Iv'e ordered a reader so that should diagnose the problem. I have also disconnected the battery which removed the warning light. It's not the answer I know but it will be interesting to see if and when it comes back on again.

I have exactly the same problem,disconnecting the battery will reset it but it may come back.
I bought a OBD reader off ebay for £20, works great. It showed up 2 faults, 2 of the 3 O2 sensors.
I also have a Toyota workshop manual, and managed to source new sensors at just over £60 each for denso ones. A massive saving.
Give me a shout if you need a hand, I am in Malton and can read it for you if it comes back on.
This is a handy site:
http://www.mr2roc.org/phpBB3/index.php
Look here for sensors:
http://www.ebay.co.uk/itm/NGK-Oxygen-O2-Lambda-Sen...
Phone and ask for Denso ones.

Edited by nottyash on Friday 9th September 22:12

[OlberJ]

Probably O2 sensors due to too much oil in those cats.

Keep checking your oil every other day.

[Skirmisheer]

nottyash said:

I have exactly the same problem,disconnecting the battery will reset it but it may come back.
I bought a OBD reader off ebay for £20, works great. It showed up 2 faults, 2 of the 3 O2 sensors.
I also have a Toyota workshop manual, and managed to source new sensors at just over £60 each for denso ones. A massive saving.
Give me a shout if you need a hand, I am in Malton and can read it for you if it comes back on.
This is a handy site:
http://www.mr2roc.org/phpBB3/index.php
Look here for sensors:
http://www.ebay.co.uk/itm/NGK-Oxygen-O2-Lambda-Sen...
Phone and ask for Denso ones.

Edited by nottyash on Friday 9th September 22:12

Thanks for the advice. I'm quite a distance from you in Huddersfield although I do occasionally pass through Malton on my way, either to Whitby or the Hole of Horcum where I occasionally fly model gliders.
I've ordered a reader for myself so hopefully that will tell me exactly what the problem is.

Are Denso better than the NGK type?

[Skirmisheer]

OlberJ said:

Probably O2 sensors due to too much oil in those cats.

Keep checking your oil every other day.

Don't worry, it's something that's always at the back of my mind. One problem is that the dipstick is a horrible one to read. There's some rather poor design in places on the MR2.

[OlberJ]

Aye you would think they rushed it out or something!

[nottyash]

Skirmisheer said:

Are Denso better than the NGK type?

Not really, just when I rang there was confusion over one of the NGK sensors as to whether it was correct. Chances are it is but to ensure the right fitment I went for Denso as thats standard fit.

[Skirmisheer]

My U48 Reader arrived this morning and I've just now had chance to put it through it's paces.

The code it produced was P0125 and that seems to suggest - Insufficient Coolant Temperature for closed Loop Fuel Control

Unfortunately that doesn't really pinpoint the problem or suggest what is not working correctly.

I'd appreciate it if someone out there with a bit more knowledge on these sort of things can suggest what's wrong and a remedy.

Many thanks.
Dave

[anonymous-user]

Well a quick google suggests it can be influenced by a dodgy lambda/o2 sensor

Hopefully this will help:

http://myweb.tiscali.co.uk/jlawson2/MK3_Repair_Man...

[Skirmisheer]

Thanks for that and for the link. I see there's a lot of useful information on that website too which could also be very useful in the future.
Dave

[Skirmisheer]

I was advised elsewhere that I could test the o2 sensors by measuring their resistance. I've done that and two were reading 15 ohms and the other 13.8 ohms. Am i right in thinking that these should therefore be okay?

Dave