Technical Knock sensor & ECU issues

[Morty Mort]

Re: Faulty ECU - Now what?

How much did you spend for the new one or it was still in the warranty period?

Got it through warranty. They even sent a Stilo specialist from another part of the country to fix it. The part itself cost FIAT 8.000 NOK I was told, and that was without any profit. This equals 800 GBP, but beware!!! These are Norwegian prices. I can still sell my 2002 1.6 Stilo for 10.000GBP.

M.

 

[Argonought]

Re: Faulty ECU - Now what?

Pretty sure you can use a second hand ECU but as Morten suggests I think you must use Examiner to proxy align the ECU to the body computer etc.

Whether the engine would run before you did this - I don't know :chin:

 

[john55]

Re: Faulty ECU - Now what?

You would have to get a 2nd hand ECU blanked first. There are some companies that do it (dealers can't). It wont proxy align unless it appears like a new one.

 

[d_ave]

Re: Faulty ECU - Now what?

The guy from the shop called me several hours after getting the car and told me that he can find an ECU from a crashed car to test whether it will work. The problem is that i don't know whether they'll be able to blank it.
Could the "new" ECU do some more damages when they fit it in? How risky is the whole operation for the rest of the electronics in the car?
The guys from the shop are pretty sure that it's the ECU, but still they want to check with another one whether the error code will be cleared or it will reappear again so they will be able to figure out whether it's really the ECU or something else.

 

[Steely]

Re: Faulty ECU - Now what?

http://cgi.ebay.co.uk/Brand-New-Fia...39:1|66:2|65:12|240:1318&_trksid=p3286.c0.m14

might come in handy


iirc the knock sensor, it detects pre-ignition or pinking and advances or retards the ignition to suit, some cars dont even have knock senosrs so i cant see it being overly bad for the car, just dont leave it to get hot sat in traffic,

 

[d_ave]

Re: Faulty ECU - Now what?

Thanks for the link Steely, i left the guy a message, i hope he'll be able to help.

Regarding the knocking sensor - with this constant error the car is running crippled eversince the fault appeared, so it is really very annoying. While it was in the shop they detected problems with the two lambda sensors and changed them, the car is running better now, but still it's not it's full potential.

BTW another strange thing happened today. I stopped the engine for a while to buy a coffee and afterwards the fault was gone! I tried reigniting the car several times but no fault code appeared! I don't believe my eyes, this has never happened before! now it comes to my mind the possibility of a bad cable wiring. They have tried the cable running to the sensor but i'm thinking of connecting two wires between the sensor and the socket, in which it goes, just to check since i think they never tried a new cable. the cable's connections are as good as new, but i don't want to exclude the possibility of a bad wiring.

 

[Deckchair5]

Re: Faulty ECU - Now what?

Yes your car will be crippled without the knock sensor. The ecu goes on advancing the ignition until the knock sensor says "no more" as it detects over advanced ignition. If the knock sensor circuit is flagged as bad then the car goes into limp mode.

I'd check for continuity in the knock sensor circuit all the way up to the ecu. That's important, not just checking the knock sensor connector but is it getting up all the way up to the ecu?

It's vital too that the knock sensor is torqued up correctly if removed or renewed as this affects when it acts. Beware if this has been removed for investigation although this should't cause a fault warning unless it's broken

Once it is working then a quick test is to physically tap the sensor with a hammer with the engine running and you should hear the tickover drop as it backs off the ignition and then the tickover gradually rises back up again to be just off knocking

The knock sensor won't advance the ignition point, the ecu does that, the knock sensor is the limit sensor

 

[d_ave]

Re: Faulty ECU - Now what?

Deckchair, what do you think, which is the more sound scenario - a faulty ECU or a bad cable? i bet on the cable! too bad i can't check this myself

 

[Argonought]

Re: Faulty ECU - Now what?

That cable itself is very unlikely to be defective (unless damaged by someone/something else) - far more likely to be a contact problem on a plug/socket at the end of the cable.

 

[Deckchair5]

Re: Faulty ECU - Now what?

Yes connectors are the first port of call at the ecu and the knock sensor connector. Eliminate the easy and cheap possibilities first

 

[d_ave]

Re: Faulty ECU - Now what?

Unfortunatelly connectors look as good as new this was the first thing to check.

 

[Deckchair5]

Re: Faulty ECU - Now what?

Not "look at" but electrically check for continuity, right up to and including the ecu
Your ecu is reporting a problem in the circuit so you need to find out if there is a problem and fix that or the ecu is wrong and you have to fix that

 

[Deckchair5]

Re: Faulty ECU - Now what?

Another few points

I might have been dreaming but i felt sure the last time i was grubbing about underneath my 1.6 that it had TWO knock sensors, one at the back and one at the front of the engine, only really visible from underneath though

The static state resistance is quite high through the sensor 5Mega ohms or thereabouts.

Here's what happens electrically, a sudden jump when it detects the wrong frequency knock. This isn't a Stilo but you get the idea

 

[d_ave]

Abnormal behaviour - any suggestions?

Hello again,

I'd like to ask about something, which my car does ever since i've bought it, but which hasn't caught my attention by now because of the other problems i had.

The situations is such, that sometimes when i'm driving and my AC is working and when i press the clutch to shift a gear my car revs up to 2000-2100 rpm by itself and after it touches this limit goes almost immideately down again by itself. Is this normal? i thought that it might be revving up to maintain some rpms, which are needed for the proper operation of the AC, but is this a plausible explanation? The fact is that it does this only when the AC is on. Also it's worth mentioning that i have the "more complicated" AC - the one with the screen and the ability to maintain a certain temperature.

Also i've read the manual and there's said that it's better to keep the AC on even in cold whether, because it's compressor is sucking out the moisture and is keeping the windows without steam on them. Is this true?

 

[d_ave]

Re: Abnormal behaviour - any suggestions?

Seams that none else is experiencing such abnormalities

 

[Deckchair5]

Re: Abnormal behaviour - any suggestions?

when i press the clutch to shift a gear my car revs up to 2000-2100 rpm by itself and after it touches this limit goes almost immideately down again by itself. Is this normal?
Try resetting the ecu by disconnecting the battery for a few hours so it relearns the best parameters. Switching on the aircon will bump up the tickover a little to compensatebut it shouldn't rev up too much when changing gear

I've read the manual and there's said that it's better to keep the AC on even in cold whether, because it's compressor is sucking out the moisture and is keeping the windows without steam on them. Is this true?
You bet your life. Absolutley wonderful in winter.

 

[d_ave]

Re: Abnormal behaviour - any suggestions?

Seams like all my problems are connected to the ECU By the way the car is for an ECU check-up and probably (finally) a change regarding my other problem with the knocking sensor. I hope everything will be finally solved today...

 

[d_ave]

ASR failure?!?!?!

Hi again to everybody,
i'm still waiting for me new ECU to arrive, i hope i'll finally get out of the knocking sensor fault nightmare...
Meanwhile a new thing popped up. While i was driving a while ago i realized, that my City is off. I reached down but accidentally hit the ASR button. ASR went off, so i hit it again to turn it ON and guess what - beep beep beep ASR failure... Nothing's lit up on the dashboard, just the warning flashed and disappeared. Tried to turn it off and on again and sometimes everything's fine, somethimes i get the failure warning. Any ideas? I'm not very familiar with the ASR, but could this have happened beacuse i turned it off and on again while i was driving? Is it again some stupid sensor that's causing it?

 

[1.8Stilo]

Re: ASR failure?!?!?!

you should be able to turn it on and off whilst driving no problems, i always use to do it on my stilo for more hands on driving! So you should be able to rule that out... now the asr/abs failure warning that comes up, this can happen on start up when the battery has low voltage, or mine use to *bleep* just before you'd stall it! I think the common things now is to either to charge the battery or get a life check thing on it, then maybe replace it and check the connectors on the battery and the earth strap from it.. Mine thru up loads of errors when the battery was near the end of its life like the above, it is common too so nowt to worry about

 

[Argonought]

Please don't start NEW threads which relate to existing ones :shakehead:

Since they are all linked, I've just merged them all together which makes it easier for everyone.

No more fresh threads please (on this subject)