The dreaded engine light........

Anonymous · January 24, 2006, 10:40

I have done a search on this, but not got a definitive answer as it would take a while to collate all the answers...........

But, what seems to be the most common reason for the engine light to come on? I had mine come on this morning going to work and took it straight to MrT to have a look at it. They are going to let me know, but I really hope its nothing too serious or expensive.

More to the point, just to have a look at it, they are charging me £89!!!! Can you believe that?

Anyway, thought I would ask so I can keep my fingers crossed.......
s:? :? s:?

edward.carter · January 24, 2006, 10:47

well i took it to a toyota specialist instead of main dealer and they looked at it for £25. any other symptoms, like lack of performance, are irregular idle, my idle was all over the place and i had flat spots, turned out my maf was faulty.

Tem · January 24, 2006, 10:57

Quote from: "John Woodward"But, what seems to be the most common reason for the engine light to come on?

Failure to fully tighten the fuel cap after fillup? s:lol: :lol: s:lol:

Anonymous · January 24, 2006, 11:02

Hmmmm........just had a call from MrT. They said that they found the fault and said it was something to do with the heater sensors on the exhaust. By this I presume they meant the O2 sensor maybe? Anyway, they are charging me £185!!!! Is this right? Or is this price meaning it is something else?

They also said that minimal driving won't do much damage to the car. Is this right? I am picking it up later and will need to drive it back later and they can't get the sensor in until Thursday. They are putting it in then, so really not sure what to make of what they said.

Anyway, I am getting it done by them as I don't have an alterternative, but I just want to know that I am not getting ripped off and I am getting told the truth.......

Any ideas?

Anonymous · January 24, 2006, 11:03

Quote from: "Tem"
Quote from: "John Woodward"But, what seems to be the most common reason for the engine light to come on?

Failure to fully tighten the fuel cap after fillup? s:lol: :lol: s:lol:

Never had that when I have done it............ s:wink: :wink: s:wink: s:lol: :lol: s:lol:

edward.carter · January 24, 2006, 11:05

sounds about right for a toyota o2 sensor swap, believe (from here) there are generic ones you can buy and fit yourself. and yep if it is the 3rd sensor in the exhaust driving it wont do any damage. There isa cheaper way but depends how much hassle you want.

Anonymous · January 24, 2006, 11:12

Quote from: "edward.carter"sounds about right for a toyota o2 sensor swap, believe (from here) there are generic ones you can buy and fit yourself. and yep if it is the 3rd sensor in the exhaust driving it wont do any damage. There isa cheaper way but depends how much hassle you want.

Right, fair enough. Well, looks like its going to be MrT for the lack of hassle then as I need the car and I don't really have time to be looking around for the alternatives and so on. But cheers for the info Edward. Kinda put my mind at ease, in an expensive way, if you know what I mean........... s:roll: :roll: s:roll:

Tem · January 24, 2006, 11:44

Quote from: "John Woodward"O2 sensor
£185

Surely that must come with a weeks cruise to Caribbean? s:shock: :shock: s:shock:

You might wanna PM Adam to see if he has any for a fraction of that..

edward.carter · January 24, 2006, 12:00

i remember someone else having an o2 sensor replaced at toyota for a similar price, it is a lot of money though, forgot about adam, he may have loads lying around s:)

s:)

Anonymous · January 24, 2006, 12:17

I need the sensor done ASAP really. I need the car a lot, haven't got the time to fix it myself or get it to a garage and I am looking to part-ex the car for and Elise next week anyway, so I need it done pronto. I COULD email Adam, but I don't know how long it would take for it to get sorted. This way, its done, fixed, drivable and sellable. Yep, going to cost me, but I need it done...........

Cheers for all the advice though!!!

Two's Company · January 24, 2006, 12:42

If it were my car and I was getting rid of it in a week I would reset the ECu to see if the lights goes out first.

If it does then you've saved £185!! s:wink: :wink: s:wink:

edward.carter · January 24, 2006, 13:04

Quote from: "Two's Company"If it were my car and I was getting rid of it in a week I would reset the ECu to see if the lights goes out first.

If it does then you've saved £185!! s:wink: :wink: s:wink:

especially as its a PX and not a private sale, if it is the o2 sensor in the exhaust and you reset the ecu, not sure how long the light would stay off for though...

Anonymous · January 24, 2006, 14:00

Nah, I would rather get it done, even for my own piece of mind to be honest. The guy who is doing the deal on the Elise is a top, top chap and I don't want to be ripping him off when he has helped me no end. Also, like you said Edward, I could reset the ECU, but how long is that going to stave off the light coming back on? There is a chance that it might come back on before I get rid, which means I am going to have to get it fixed anyway.

It needs doing, I will get it done............

Anonymous · January 24, 2006, 16:06

Ok, update. Just got back from picking the car up from MrT. Apparantly, its NOT an O2 sensor but they traced the fault to a faulty heater sensor circuit, bank 1, sensor 2. No idea what that means so if anyone can shed any light on that I would be grateful.

Thing is, driving it back, there was no light on! Don't know if its because the engine was cold, but it didn't come on during my short 2 mile trip from the dealer. I hope that its not just a one off and I am paying a fortune on thursday to get it fixed for nothing.........

The part including the fitting is £185, as they said. And they have still charged me the £89!!!

But they did wash the car.......... s:roll: :roll: s:roll:

Slacey · January 24, 2006, 16:12

It is still an O2 fault, and they will have cleared the CEL with their code reader - drive it around some more and see if it comes back.

Anonymous · January 24, 2006, 16:51

Quote from: "Slacey"It is still an O2 fault, and they will have cleared the CEL with their code reader - drive it around some more and see if it comes back.

Right oh. Cheers Sean

Anonymous · January 24, 2006, 18:34

Heater circuit malfunction in O2 sensor seems to be rather common. Very easy to replace yourself.

spit · January 24, 2006, 22:11

John,

What the ECU sees to register a "faulty heater circuit" is an open circuit across the wires feeding power to the heater element in the sensor. Its most extremely likely(!) that the element has gone.....and v.v. unlikely that the open circuit is anywhere else in the wiring between sensor and ECU.

So, replacement of the sensor will solve this - but if you want a peace of mind check, put an ohm-meter across the two black wires on the plug. Don't try this on the blue & white wires - they won't like it.

A healthy heater element will read about 15 ohms give or take. A duff element will be open circuit.

When mine went awol, the only discernable symptom was the CEL - once hot exhaust gas gets to the sensor, the heater circuit is effectively redundant. There is a "patch-up" fix you can perform, but given your plans for the '2, looks like a new sensor is your best bet.

Ste

Anonymous · January 24, 2006, 23:05

Quote from: "spit"John,

What the ECU sees to register a "faulty heater circuit" is an open circuit across the wires feeding power to the heater element in the sensor. Its most extremely likely(!) that the element has gone.....and v.v. unlikely that the open circuit is anywhere else in the wiring between sensor and ECU.

So, replacement of the sensor will solve this - but if you want a peace of mind check, put an ohm-meter across the two black wires on the plug. [you]Don't[/you] try this on the blue & white wires - they won't like it.

A healthy heater element will read about 15 ohms give or take. A duff element will be open circuit.

When mine went awol, the only discernable symptom was the CEL - once hot exhaust gas gets to the sensor, the heater circuit is effectively redundant. There is a "patch-up" fix you can perform, but given your plans for the '2, looks like a new sensor is your best bet.

Ste

Interesting you should say that it will make the element redundant when the heat gets to it as the light wasn't on. I guess it would be a combination of what Sean said about them resetting the readout and what you have said above. My Dad has a meter, but he is unfortunately, 150 miles away!!! And I don't think I will be buying one just yet, so will go with your latter suggestion and just get it fixed! s:wink: :wink: s:wink: s:lol: :lol: s:lol: Like you said, I have other plans for the 2 anyway, so I think its worth it. I might be changing her for and Elise sometime soon, but she has to keep running!!! s:D

s:D

spit · January 24, 2006, 23:32

Sorry, my bad explanation.......its been a long drive back from Coventry tonight s:shock: :shock: s:shock:

By redundant I mean that the function of the heating circuit is only to get the sensor up to temperature so that its firing accurate voltages back to the ECU: the car will function fine once the sensors are hot, and the exhaust gas will eventually take care of that when the engine is run for a bit.

If the heater circuit has failed, the CEL will trigger...... although ......my CEL did come and go a few times before the element finally packed up completely. Don't know if thats the norm, but you could be in this twighlight zone of intermittent (& impending) failure too. Maybe it starts to fall outside of ECU tolerances when its old and tired and hot s:?: :?: s:?:

Only other nugget I have is that - once the circuit was well and truly knackered (because I'd cut the wires!!), I noticed that an ECU reset gave me a free run before triggering the CEL, which only came back on second start-up.

Anonymous · January 25, 2006, 10:21

Quote from: "spit"Sorry, my bad explanation.......its been a long drive back from Coventry tonight s:shock: :shock: s:shock:

By redundant I mean that the function of the heating circuit is only to get the sensor up to temperature so that its firing accurate voltages back to the ECU: the car will function fine once the sensors are hot, and the exhaust gas will eventually take care of that when the engine is run for a bit.

If the heater circuit has failed, the CEL will trigger...... although ......my CEL did come and go a few times before the element finally packed up completely. Don't know if thats the norm, but you could be in this twighlight zone of intermittent (& impending) failure too. Maybe it starts to fall outside of ECU tolerances when its old and tired and hot s:?: :?: s:?:

Only other nugget I have is that - once the circuit was well and truly knackered (because I'd cut the wires!!), I noticed that an ECU reset gave me a free run before triggering the CEL, which only came back on second start-up.

Ok then, that kinda explains why the light DIDN'T come back on this morning after the same jounrey I had when it DID come on yesterday. As Sean said, I guess they would have reset things, but its probably still worth getting fixed as its likely to go again anytime. Problem is, not really knowing WHEN it will go and trigger the light......

I'll just get it fixed.........