First Scan - anybody fancy a gander ?!

[simonbuk]

F*ck me - why is life so difficult when you are trying to fix things ?!

Theres good news and bad news.......... made sure i had the latest version of Elanscan, went to the car to start recording data, no info received from the car. Why ? It was working before ?
As my cable isn't very long you can't have the laptop sitting on the seat, gotta go on the floor slightly propped up. Realised a couple of the wires to the circuit board have now broken off

F*ck, f*ck, and double f*ck.

No more recording data until i can work out where they go and get a soldering iron. F*ck again.

As i was fairly confident my O2 sensor was dead and have borrowed a socket removal tool and a new sensor from ChrisM (thanks Chris ) I saw no harm in swapping it over to see what happens.

vroom, vroom, here we go, feels like the Elan it should be. It struggled to get anywhere near 5,000 revs (or I lost interest as it just seemed to sound a little harsh/struggling), but now speeds up quickly through the gears. So much better.

Now wheres that soldering iron..............

[simonbuk]

Any why wasn't it throwing up an EML light ?

And why/how was it sorting out the correct air/fuel ratio ?

[chrism]

Yep I've got one of those on the shelf too...

Seriously tho' it was good to meet up with a local, 'fellow sufferer' - and even better that an m100 fix (for once) seems to have become so simple.

edit: I reckon the heat from the exhaust stream was sufficient to warm up the O2 sensor, so the ecu was 'happy' with a response - and because it wasn't aware that there was a fault it didn't throw up an eml...

Keep in touch

[RonR]

Hi Simon,

There are 3 conditions which have to be met for a Code 45 (Rich Exhaust Indicated):
1. O2 sensor voltage above 0.85V for > 10 seconds
2. Throttle position between 3.5% and 13.3%
3. Engine Speed below 3000 RPM

It's on page 66/67 of the Closed Loop manual.

So it looks like the EML would only be triggered if you're cruising along a motorway / A road.

[simonbuk]

Ah interesting - thanks Ron

I drove it all the way from Stratford Upon Avon to the south coast but I guess I was probably over 3K revs most of the way !!

[chrism]

I saw this on p197 of the closed-loop manual:-



...and it seems to tick a few boxes? (Interesting...was the sensor sooty and/or white?)

Surely, there must have been some <3000rpm driving that might have lit up the CEL? - Or, perhaps, the CEL bulb could have 'gone' in some way?

[simonbuk]

Yes, there must have been some under 3K revs obviously, the two other criteria have to be met as well. Don't know how the O2 sensor gets a voltage of over 0.85 for ten seconds or more if it is broken ?

[chrism]

I'm just thinking, weren't those 3 criteria were being met when you were getting your SimonBUK1.zip tickover data(?)- and still you had no CEL.



Your O2 sensor certainly gave a higher signal than the usual range in black. It might not be broken but merely contaminated or clogged, I'm wondering?

It seems from your data that your sensor voltage was higher than 850mV for 5mins or so before you switched off - certainly well more than 10s.

It'd be interesting to see an Escan with that spare sensor before you replace it with your new RAuto unit. Pop in for a coffee sometime and we'll use my cable - or post it here if you get your own cable sorted

Oh...and bring your old sensor if you decide to pop in...

[simonbuk]

The O2 sensor didn't look too bad ?

1000018876 (2) (1)~4.jpg

1000018877~4.jpg

But when I checked the voltage between the two same coloured wires - there was none - which I believe are the heater wires ?

[Tuga2112]

But when I checked the voltage between the two same coloured wires - there was none - which I believe are the heater wires ?

you wouldnt get any readings for voltage.
you need power in the circuitry to be able to read voltage.

you need to check for resistance.

i dont know the color coding off the top of my head for all the wires. but from memory, in the harness yellow/brown and blue/white are the power feed for the heater element and signal for the ECU respectively.
i would assume black would be ground, but from memory i dont recall a black wire

[simonbuk]

Mine has 2 black wires !!

[simonbuk]

And sorry, I meant resistance. Had nothing.

[chrism]

Tuga beat me to it cos I needed a pic. I was up to my elbows with this stuff ages ago and I wish I'd saved the emails



The lhs slate/green lead is the signal lead back to the ecu and enters the rhs O2 sensor as the black lead in the pic.

The lhs brown/yellow is the heater supply. It only gives a supply when the engine is running or ticking over and the red ign light is OFF. It enters the sensor as the bottom white lead in the pic.

The slightly hidden lhs black (under the slate/green) is the heater 'return', which is an earth, and enters the sensor as another white lead on the rhs of the pic.

As Tuga says check the two whites of the (disconnected) sensor with the resistance side of your m/meter to see if the heater supply is intact. You should get a reading between ~3ohms and ~15ohms or so if the sensor isn't broken. It's a kind of 'continuity check'.

I'm struggling to remember but I seem to think I checked the supply voltage with the sensor disconnected from the multiplug. The engine should be ticking over with the red ign light OFF. I set the m/meter to read 20Vmax and probed the lhs m/plug part between the brown/yellow supply and a convenient earth - the braid at the bonnet hinge - looking for a voltage to supply the O2 sensor.

So, yes, the two whites are heater supply and return but it seems you looked for a voltage somehow - and I'd have done this in a different way (with the engine running between brown/yellow and earth of the lhs m/plug).

With utmost respect I reckon it'd be easier to do an EScan to see if your O2 sensor works okay. - I did all this stuff to find out why mine (actually the one you've borrowed) didn't. (It had de-pinned behind the wheel arch )

My spare looked a bit sooty like yours (not white tho') but I cleaned it with white spirit, carb-cleaner and an old tooth brush (in spite of recommendations not to). I tried it in my m100 later and it's fine . I initially thought it was broken so it didn't seem to matter at the time...

[Tuga2112]

Tuga beat me to it cos I needed a pic. I was up to my elbows with this stuff ages ago and I wish I'd saved the emails

its harder to forget when after you done it, you need to look through all of it again for hours while doing video editing

but seems like i was wrong about the blue/white wire?

[chrism]

Yep, signal lead should be slate/green, black is definitely an earth + NY is the brown/yellow heater supply:-

image sharing

[simonbuk]

So, yes, the two whites are heater supply and return but it seems you looked for a voltage somehow - and I'd have done this in a different way (with the engine running between brown/yellow and earth of the lhs m/plug).

No checked for the resistance for the two same coloured wires - there wasn't any (in my case they were two black wires). Checked the same on my other car and it showed some resistance, likewise for the one you have lent me.

Have a new one arriving today - hopefully - so will put that in and see how it goes.

[simonbuk]

Right, new O2 sensor in, ElanScan cable resoldered , another file created whilst just idling but had already been out on a run -

SimonBUK2.zip

[RonR]

Exactly what I'd expect to see with a functioning O2 sensor!

O2 Volts.jpg

[simonbuk]

Yep - going out for a quick blast to get some extra data

[simonbuk]

And after a run ragging it a bit -

SimonBUK3.zip

Not sure why the power figures are nonsensical ?

Suggesting I can hit full boost and air/fuel ratio is OK.........