Engine Management Code Reader For 1998 Avensis

[talldave]

I have a 1998 Avensis (1.8 petrol, GS Auto, 7A-FE, 92,000 miles). Over the last week the engine management light has come on a few times. Sometimes just for a few seconds, sometimes for a minute or two, then it goes out. The car seems fine and drives OK. Is there a code reader I can buy to read the fault code? Can anyone recommend a code reader and where I can get one. Thanks.

[Konrad C]

You can get the code from the car without plugging in a code reader!

What you need to do is use a paperclip or wire as a jumper between terminals 4 & 13 on the OBD socket.

Turn key to ign' but do not start the engine. The EML, SRS and ABS lights will flash.

The pattern of the flash gives the fault code - 21 = two quick flashes followed by a single flash, then a gap before repeating or if there is another fault code that will be flashed too.

If you search my posts, you will find more details on the subject plus what the codes mean. 21 means O2(leanburn) sensor fault.

Since your car is pre-2000 you may find that some readers will not work.

[talldave]

Konrad - thanks for the info. I found your other posts and did as you suggested. Code is indeed 21 (O2 sensor).

For a new sensor:

Toyota quote £416 plus VAT !!!

www.gendan.co.uk quote £146 inc VAT

lambda power quote £140 inc VAT

The light has now gone off and hasn't yet come back on. It has been on 2 or 3 times in the last 10 days but never for very long (minimum of 5 seconds, maximum of about 4 or 5 minutes. Just is when the engine is cold. It has so far gone out when it gets warmed up.

Do you think I actually need a new O2 sensor? Could it be something else - e.g I know that I need to change the spark plugs soon as they've not been changed for nearly six years (six years is the recommended interval according to my Haynes manual). If I change them could this fix the problem? Obviously I don't want to replace the O2 sensor unless I really have to.

Thanks for your help.

[Konrad C]

Konrad - thanks for the info. I found your other posts and did as you suggested. Code is indeed 21 (O2 sensor).

For a new sensor:

Toyota quote £416 plus VAT !!!

www.gendan.co.uk quote £146 inc VAT

lambda power quote £140 inc VAT

The light has now gone off and hasn't yet come back on. It has been on 2 or 3 times in the last 10 days but never for very long (minimum of 5 seconds, maximum of about 4 or 5 minutes. Just is when the engine is cold. It has so far gone out when it gets warmed up.

Do you think I actually need a new O2 sensor? Could it be something else - e.g I know that I need to change the spark plugs soon as they've not been changed for nearly six years (six years is the recommended interval according to my Haynes manual). If I change them could this fix the problem? Obviously I don't want to replace the O2 sensor unless I really have to.

Thanks for your help.

[Konrad C]

Hi Dave. Glad you found my post helpful. Watch the petrol, and check the nuts holding the sensor are tight. The heating circuit within the sensor could be starting to fail. So long as the sensor is the genuine Denso sensor, then you will get it at a fraction of Toyota prices. Your spark plugs do not have any effect on the sensor, but it may be wise to change them. You will be surprised how well the plugs have kept in good condition after 6 years. I think mine will be due for a change too.

[talldave]

I've replaced the oxygen sensor and the warning light now doesn't come on. I tried to clear the code from the ECU by removing fuse EFI for 30 seconds (this is what I read needed to be done). This didn't work. I tried removing it for 10 minutes. This still didn't work - i.e the diagnostics still flash code 21. Any ideas how to clear the code (other than disconnecting the battery)?

[talldave]

Do I still need to be in diagnostic mode (i.e. have connection between OBD pins 4 and 13) when I remove fuse EFI?

I didn't, so could this be the problem?

[Konrad C]

Dave,

Check the connection at the sensor, making sure it is clean. Then retry pulling the EFI fuse in the engine bay again for about a minute.

Run the car and drive it for bit and it might settle. Hopefully the fault code will be wiped from memory.

So long as the MIL light is off, I would not worry.

Kon.