Help me with sorting some error codes please

Hello,
i recently bought a 2002 Stilo 1.6 16V. it is on about 41,000 miles. about a week after buying it i got an engine fault light on. i bought the car from a person, not a dealer and it was recently imported, so i have no connections with previous garages. so i brought the car to a garage i trust and the guy cleared the engine fault, saying that probably the reason was bad gasoline. the codes were related to the knock sensor and some manufacture-specific code. after a week or so the engine light came on again, stayed on for about week and a half and went away by itself. i decided to do some research by myself and ordered an ELM327 reader. it just arrived tonight, so i connected it and here is the result:

P0325, P0520, P1687. after resetting these codes they reappeared right after starting the engine again. the engine failure light is off, but still these codes are there.

i did some searching and i have some suggestions pointing towards the oil pressure sensor, the knocking sensor and the throttling body, but don't know what to do - i don't want to start changing components because of error codes. the car runs well, probably sometimes there's a slight sluggishness during acceleration, which probably leads again to the throttling body. should i start checking the cable connections? where exactly are the throttling body and the knocking sensor? what about the oil pressure sensor - why there's an error code regarding it since the engine failure light is off and the oil pressure light is also off?

also i had another strange situation this morning. last night there were some severe storm and heavy rain. i used the wipes a lot. this morning when i turned the car on the wipes started by themselves! they were switched off, but still they started wiping. i restarted the engine and again they started going by themselves and stopped right at the middle of the windscreen. i tried the sprinklers, both front and back, and they went back to normal position and didn't cause any trouble any more. this evening there was rain again and they functioned without any problems. any suggestions about this strange behavior?

i very sorry for asking so much questions since i am a newcomer, but i started checking the forum as soon as i bought the car.

Re: Help me with sorting some error codes please

I would guess your car's been hanging about a bit and has damp or poor contact is various places
P0325 Knock sensor
This is a peizo shock sensor if yoiu like which detects the enigne just starting pink and retards the ignition so it's just off pinking. It's a circular item around the back of the engine. Most probably its connector just needs pulling aart and cleaning with contact cleaner. If you need to replace it, it's not that expensive BUT YOU MUST use a torque wrench and torque it properly to fit a new one. ou can test if its's working by gently tapping it with a hammer with the engine running and you would hear the engine note change as it backs off the ignition

P0520 Oil pressure sensor
Almost identical problem i would guess of poor contact at the oil pressure sensor needing disconnecting and electrical clean up of contacts

P1687 Fiat generic. Are you sure that's the right code number as that's an oddball one?

Wipers? Probably the same problem of poor contact a its connector. The grease in the motor causes problems in cold weather as it solidifies badly and prevents electrical contact inside the motor with all sorts of weird stuff happening. Mine jump about on their own for a while when it's really cold but work fine once warmed up.

If your car's been sat around in the damp for a while i expect you'll have a merry go round of connectors needing attention until they're all sorted

Re: Help me with sorting some error codes please

hello,
P1687 is :
"interruption of throttled body self learning for incorrect environmental parameters".....
Could be a loose contact or bad earth connection (or many other causes)

good luck!

yellowstilo

Re: Help me with sorting some error codes please

How good is the battery? you could try disconnecting battery for a few hours to reset the ecu.

Re: Help me with sorting some error codes please

Thanks a lot for the quick answers! i'll start checking the connectors this weekend - i need to get some good contact spray. i have WD40 - is it good is it or do i need something better?

the battery seems ok i'll check how old is it, but i think it was replaced recently.

yesterday morning the car lost power after 3000 rpm. soon after that the engine fault light came on again. last night, when i connected the reader there was a new code - P1325 with a pending status. again this is the knock sensor, but this time the circuit - i am beginning to doubt whether i will pass only with a connector check there

another thing that comes to my mind just now is that after cleaning the engine fault message it reappears about the time i get low on fuel. is there a possibility that there is some dirt in the gas thank, which the engine starts sucking when the fuel level is low? i think i should get some fuel line cleaner to see if there will be any improvement.

Re: Help me with sorting some error codes please

No, WD40 is a lubricant, different ball game. You want electrical contact cleaner which removes the anodised layer on the top of the contact surface and brings it up like new. Available at Halfords or any electronics store - about £4 a spray can

P1325 is knock sensor circuit and the connector is in the circuit so same advice really to start with

Why did they think it was bad fuel before? Do you suspect water in the fuel? Certainly water will collect in the bottom of the tank

So it runs all right until you get low on fuel- is that what you're saying?

Re: Help me with sorting some error codes please

Deckhair, that's exactly what i'm saying - low fuel = bad ride... i took from a friend a professional repotec gas additive and i think that water (or other bad particles) are gone from the gas tank. also i did some other things, which lead to more questions than answers.
i drove the car for polen, gas and air filter change. also i took my ELM327 reader to show it to the mechanic. he was very impressed by it's funcionality, especially the live data (hm, i think that the moment i start teaching the mechanics what to do is the moment to go fa far away from them, but still...)
he said that the car is over-revving a little and it needs a throttling valve cleaning - something which as i'm checking now is in the guides section and could have been done by myself... well, he changed the filters, did the throttling valve cleaning and said, that he couldn't find the knocking sensor - one of the main purposes for my visit!!! very disappointed i left the garage just to notice, that if i turn off the aircon the rpm-s are going nuts on idle - they are jumping from about 900 do 700 all the time. after a check in the forum i "reset" the throttling vale (waited one minute with ignition to on, but with turned off engine and after that waiting for 30-40 seconds without touching anything) and now i think that the rpm-s are steady ad about 800 - i'll connect the elm tomorrow to check. but still i need to find the knock sensor - do you have some picture of it or a guidance where can i find it and what exactly to look for?
also something strange happened for the second time tonight. several days ago i noticed, that my steering wheel needs to be a little bit to the left for the car to go straight ahead. ok i said, the wheel needs adjusting. but soon after this the car was left under the hot sun for the whole day and this "problem" disappeared!!! tonight it reappeared again - i parked the car to buy some things from the shop and just after that the car started going to the right, so i need to keep the steering wheel a little to the left for it to go straight. i am very confused - what might cause such change? the tires are all at 1.9 - i checked them a few hours ago.
i am beginning to think that the car has a mind of itself and an edgy character! there seems to be problems, appearing and disappearing by themselves and strange, unexpected faults, which seems to go away after some time!

Re: Help me with sorting some error codes please

The knock sensor is circular -about 30mm diameter with a bolt through the middle. Looks a bit like this but yours will have a wire cable coming out of it.
It's often around the back of the engine and easier to see from underneath. It'll be bolted directly to the engine and between a couple of cylinders. If you remove it then you MUST use the correct torque to refit it



It may look more like this, item 3b- engines vary
But if a mechanic can't find a knock sensor within 5mins then I'd go elsewhere

Your steering might be many things but i'd check tyre pressures - wheel sizes and tyres vary and you have to go with what you feel is right but i have mine 205/55/R16 on 2.3 bar. At 1.9 bar mine would be wandering all over the road

Check for wear in the suspension. steering. Particularly look for wear at the track rod ends

Strange noise when accelerating

Hi there,

I have the following strange "problem" - yesterday after taking down my 2002 Stilo 1.6 backwards from a sidewalk i heard the front bumper to "scratch" the edge of the sidewalk. Right afterwards a strange noise appeared - something like what's heard from a vibrating cellphone, put on a flat metallic surface, but a lot louder. Sometimes it sounds like as if i have fitted in one of these sports exhausts, which produce an annoying loud sound, but i can't figure out if you could hear the same thing from outside the car or only from the inside. Also i noticed, that most of the times it's heard on second or third gear, when turning more rapidly on a sharper conrner. It appears between 2,000-2,500 rpm and is pretty annoying.
I went to an inspection channel last night and went under the car, trying to find out whether some of the plastic covers could have disconnected and to check whether everything's fine with the exhaust pipes and system. Everything seamed OK, apart from the front right plastic cover, the one near the wheel. It got detached a few months ago, but i reattached it and now it's a little bit loose, but it's amost impossible for it to cause such a loud noise. I thoroughly checked the front bumper and it seams to be OK. I've also checked the exhaust system and it stays pretty solidly in place.
There should be something, which might have come loose and probably catching the motor vibrations at 2,000-2,500 rpm, it starts rattling, but i can't figure out what it might be. Do you have any suggestions of what this could be? The noise is not a real problem, but it's definitely very annoying to hear it from such a quiet car as mine.

Hi again,

today i finally went to a garage for knocking sensor check-up and possibly a change. They hooked up a large code reader to it (large i mean a giant wardrobe-like computer) and they told me the lambda sensor had gone bad... WTF - i have a ELM327 reader and the only thing it shows are the two codes for the knocking sensor and nothing close to the lambda! what followed was an explanation that the two things were "connected" and the error codes i'm reading regarding the knocking sensor were due to the faulty lambda sensor. also they explained to me that i'm getting a little high consumption because of the lambda. it's true that the consumption is about 1-1.5 l/km higher, but i thought that this is because of the heavy traffic every morning and because the car is constantly running with the AC on. in friday i'm booked for lambda sensor change and they persist on not changing the knocking sensor because "it's working fine". what do you thing, am i an idiot for believing the ELM327 or they are idiots trying to bug me?

re: Knock sensor & ECU issues

A fault code fires up when the item has gone beyond limits. A lambda sensor can be within limits so fires no code but sluggish in operation which puts everything out.

With a laptop hooked up you can see the lambda sensor trace and check the sensor for yourself or even watching a multimeter connected to the lamdba isn't difficult


Knock sensor is pretty easy to check. Have the engine warmed up and on tickover and just knock the sensor with a hammer (not too hard) you should hear the tickover change as the ignition timing is backed off and slowly advances again

I'd tend to believe the wardrobe

You have two lambda sensors though.
Pre cat one does the big job of keeping fuel/air in trim
Post cat sensor detects anything up with the cat


Here's a trace of my lambdas doing their job. Pre cat lambda nicely oscillating between 0.2 to 0.8v about every 1.5secs at tickover

re: Knock sensor & ECU issues

Thanks a lot for the quick answer and the picture! They showed me something like this on a screen on the wardrobe and when they revved the engine the graphic just died. Does such behaviour mean that the sensor is faulty?

re: Knock sensor & ECU issues

The graphic just died? Sounds like the wardrobe died.
No it should always produce a trace of some kind. A recent one i tested showed flatline at 0.2v Unresponsive but it still showed a trace and needed renewing

Common failure is it's internal heater circuit so it takes ages to warm up . You can check that circuit resistance when everything's switched off. Should be very low resistance just a few ohms

re: Knock sensor & ECU issues

I'm just imagining it - a dying wardrobe
I meant the line went to a flat line for a moment and afterwards it continued to oscilate. Should it be oscilating constantly? If it does, i'll start believing the wardrobe...

re: Knock sensor & ECU issues

On tickover it should be as shown in the top trace. A flatline on tickover would show a problem. Often the heater heater breaks, then it cools down too much at tickover and doesn't work properly hence the flatline

Pricey item at £60 about 80 euros but you're probably wasting a fifth of your fuel on every fill up because of it so it soon pays for itself

re: Knock sensor & ECU issues

Thanks a lot for the advice, they're changing it in friday.

And what about the knocking sensor, is there some connection with the lambda? It's even more pricey - about 100Eur just for a tiny sensor... they told me that they cannot decide whether it's for change too until they've changed the lambda. I believe they're talking about the "front" lambda, since the one near the cat was behaving "fine".

re: Knock sensor & ECU issues

Well knock sensors rarely go wrong, it's just a peizo transducer and they're pretty robust. Remember that a fault code doesn't mean you have to replace that item, it means that circuit has given a few out of limit readings so it may simply be a poor/unreliable connection to the sensor.

Do what i said and with the engine warm and on tickover give the knock sensor a tap and listen for the enigne to retard the ignition and the tickover change then gradually come back again. If it does then it's working

Faulty ECU - Now what?

Hello,
I have posted several times threads regarding my problem with my knocking sensor. Finally a new knocking sensor arrived at my dealer and i left the car for fitting the new one in tuesday. They changed it but the problem remained. After two days and infinte count of checkups and attempts to find the problem just anywhere they told me that probably the problem is due to a faulty ECU unit. I'm getting the car in two hours and i'll be able to speak with them in person, but i don't like the diagnosis at all! Do you know some estimate price for a new ECU unit? Since it's paired with the keys and lock etc, should i change them also? How about an ECU from a crashed car? Will i be able to fit it in and what should i also change to get it to work properly?

BTW just how bad is the knocking sensor error for the car? i mean what problems it might cause if i just leave it and drive it like this?

Re: Faulty ECU - Now what?

I changed (or FIAT did) my ECU. No locks etc. was changed then. Maybe there was a proxy alignment or so, but I really don't know. The ECU crashed after 2 weeks of ownership...

M.

Re: Faulty ECU - Now what?

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