Engine Warning Light - What Does It Mean?

[lestermester]

Hello,

I have a Avensis Verso '02 a bit like this one:

And an engine warning light came on the other day...i took a picture of it:

I dont have an owners manual & was wondering what it means?

There are no unusual noises etc so i dont know what it means.

Can anyone help? I'd be grateful for your replies.

Many thanks

[t-spiritpete]

Hello,

I have a Avensis Verso '02 a bit like this one:

And an engine warning light came on the other day...i took a picture of it:

I dont have an owners manual & was wondering what it means?

There are no unusual noises etc so i dont know what it means.

Can anyone help? I'd be grateful for your replies.

Many thanks

Hello mate, you don't say whether it is petrol or diesel but anyway the first thing to do in this case is disconnect the Neg Battery lead for a few minutes which may clear the fault, if the light comes back on again you will need to have a garage (it can be any good garage) tell you what the fault code number is by using OBD reader and we can go from there.

regards Pete.

[lestermester]

Sorry i should've said...it's a petrol.

[lestermester]

Hello mate, you don't say whether it is petrol or diesel but anyway the first thing to do in this case is disconnect the Neg battery lead for a few minutes which may clear the fault, if the light comes back on again you will need to have a garage (it can be any good garage) tell you what the fault code number is by using OBD reader and we can go from there.

regards Pete.

Thanks for the info, pete. I'll follow your suggestion and see what happens.

Cheers

[Lizzi]

Have you managed to clear your engine light yet?

Mine came on a couple of weeks ago. Had it checked and it was the O2 sensors. Cleared the error, but it came back on a couple of weeks later.

Have had to get the sensors replaced, so it could be something like that on your. What mileage has it done? I think its quite a common fault.

[lestermester]

Have you managed to clear your engine light yet?

Mine came on a couple of weeks ago. Had it checked and it was the O2 sensors. Cleared the error, but it came back on a couple of weeks later.

Have had to get the sensors replaced, so it could be something like that on your. What mileage has it done? I think its quite a common fault.

Hi Lizzi

I tried the 'disconnect the -ve Battery lead' suggestion...

...then as I was about to take a picture of the dashboard indicators showing the cleared fault...it reappeared!

So, I still have the problem. Looks like the only way to diagnose this is by taking it to a garage!!!!

Agh!!

p.s. car's done about 85k miles.

[bestseany]

Is it the 2.0 petrol? I'd actually bet money on it being an O2 sensor :-)

But you will need it plugging in to a diagnostics computer to find out what the specific fault code is.

[lestermester]

Is it the 2.0 petrol? I'd actually bet money on it being an O2 sensor :-)

But you will need it plugging in to a diagnostics computer to find out what the specific fault code is.

Hello,

Yes, it is a 2.0 petrol engine.

Thanks for the info.

What does the O2 sensor actually do? Does it control the fuel/oxygen mixture?

Edit: Just read this on the internet:

Th­e oxygen sensor is positioned in the exhaust pipe and can detect rich and lean mixtures.

[Bob Taylor]

Is it the 2.0 petrol? I'd actually bet money on it being an O2 sensor :-)

But you will need it plugging in to a diagnostics computer to find out what the specific fault code is.

Hello,

Yes, it is a 2.0 petrol engine.

Thanks for the info.

What does the O2 sensor actually do? Does it control the fuel/oxygen mixture?

Edit: Just read this on the internet:

Th­e oxygen sensor is positioned in the exhaust pipe and can detect rich and lean mixtures.

The oxygen sensor is part of the emissions control system and feeds data to the­ engine management computer. The goal of the sensor is to help the engine run as efficiently as possible and also to produce as few emissions as possible.

[lestermester]

well - finally got it diagnosed and guess what, boys n girls?...the code was P1155.

Is that one of the O2 sensors?

I bet it's expensive, which will P1155 me off.

[bestseany]

That code is "O2 Sensor Heater Circuit Malfunction Bank 2 Sensor 1"

This means that the heater within one of your oxygen (lambda) sensors has failed. The sensor itself will be working ok but only once it has warmed up from the engine gases. O2 sensors don't function correctly until they reach a certain temperature.

The sensor that's failed on yours is before the catalytic converter and is in bank 2, which I think is the one in the middle of your exhaust manifold (facing you), as it feeds from cylinders 2 and 3. It's very easy to change as long as you have the proper socket for the job. A new sensor from Toyota is about £150.

You can test the heater circuit in the sensor by disconnecting the plug and testing the resistance across the two black wires with a multimeter, it should read about 16ohms if I remember correctly.