Technical Pesky ABS light grrrrrrrrrrrrrr

[bertiebumblebee]

HI All ,

A little technical assistance if anyone would be so kind

early 2004 FIAT STILO 1.9 JTD 115

Intermittently when stood or when driving the ABS warning light illuminates.
After turning off the car the fault does go away sometimes for minutes but usually for weeks. Today the ABS light came on - then a message appeared on the display saying loose connection, then the speedo stopped working. After restarting the car all was ok.

Am I right in the belief that on cars with ABS the speedo signal comes from the ABS. If so it would appear these problems are one and the same does anyone disagree?

Does the speedo signal come from one wheel in particular?? If so why does the ABS light not normally affect speedo operation but on this occasion it did (could it be a bad connection that got worse and took the speedo out)

I presume FIAT ECU scan could tell me which wheel has the problem. Am I correct in thinking these error codes will be stored.

I am thinking this is an electrical problem (wiring ) but would a wheel sensor be more likely.

Any help with this would be appreciated - thanks in advance.

 

[dtimmins1985]

Loose connection and the errors you describe sounds like a bad battery or a bad earth.

Abs sensors are on each hub so there is 4 in total.

 

[Artermis]

I'd be inclined to agree with DTimmins because you've shown a loose connection fault too, it sounds more like a power related issue.

Did just the speedo drop out or did all the gauges, tacho (revs), fuel and temperature also stop working?

The systems on the car are particularly sensitive to voltage drop, so if for some reason you've done something that's dropped the voltage, say turned on headlights, full beams, radio, wound down your window, heaters that could trigger error messages quite easily on a weak battery.

We've just hit another cold snap in the weather too. Freezing temperatures put an additional strain on the battery and will often expose a weak or elderly battery.

Test your battery with the ignition off and look for at least 12.6v and with the engine running for at least 14v.

Regarding fault codes, FiatECUScan has been renamed MultiECUScan but yes, you will be able to read these fault codes using the software and they should indeed be stored. You'll want to consult the MultiECUScan (MES) website to determine whether or not you need the licenced version of the software (vs the free version) and what cables you require in order to communicate with the ABS ECU.

 

[bertiebumblebee]

Progress so far

Tried MES to look for codes and there were a few ABS ones stored. I cleared them off and almost immediately the left rear abs sensor came up again as a fault. One thing I am not sure about is if this rear wheel sensor could cause the speedo (all other clocks on the dash are unaffected) to stop working. I will need to solve this rear wheel issue first.

I will then see if any other issues arise. MES scan did see wheel speed data on all four wheels but I did have the back axle off last summer to replace the rear bushes so it could be a bad connection where that ABS sensor connects onto the car ( unlikely after this long) after checking that I suppose it will be a new wheel ABS sensor and after that a rear wheel bearing if required. Don't you just hate this, as I call it , 'main dealer mentality' of just throwing new parts on until the fault clears. At least these parts are reasonably priced. Does anyone agree with this logic or am I talking Bull.

It may also be new battery time - 11.78 volts read by the scan tool before engine run ( car had not run for three days ), Voltage comes up fine when started but ABS fault sometimes comes on randomly at Motorway speeds so I presume battery voltage would be good at that time. I was hoping to make this battery last a little longer but accept I may not be able to.

This car is a 200 quid cheap car purchase last summer but it did need replacement rear bushes, front arms, drop links, one rear caliper, brake disk and pads all round and various other bits to get through MOT and running correctly. Therefore I don't want to spend too much more on it just yet. Having said that I think the Stilo JTD is a very under rated car.

Any help, suggestions, or comments that I am talking drivel will be appreciated.

 

[Artermis]

Progress so far.....

Hey Bertie...

Your logic does seem good. Without sifting through wiring diagrams I couldn't tell exactly how or where the speedo gets its speed signal from either.

The one note of caution I would sound is regarding the battery. It sounds like you've used an OBD diagnostic tool to check the battery voltage? If you have, don't....

Sometimes the old ways are the best. You want to know the true status of the battery, test the battery. You can't go testing it with ignition on as it's under load at that point.

If it's not a tool you have access to a lot of motor factors or even somewhere like halfords will do you a battery check with their proper gizmos, often for free (be sure to ask how much it is before letting them do it!).

My priority would be to get the battery tested properly and replace if diagnostically indicated. Genuinely don't underestimate just what weird and wonderful things can and will happen with a failing battery.

If you replace the battery then I would allow a test period to see if the fault persists once battery has been replaced before considering replacing the rear wheel sensor.

Unfortunately, in my opinion at least, there is no such thing as a cheap car, as they all want money spending on them for something. My wife's Peugeot is looking at wanting a new Eolys fluid bag (5 litres for £150) and possibly a new DPF, for another £150, plus two new back tyres. That's got to be £400 on a car I only paid £800 for. That's just the way it is.

Good luck mate and report back with updates. Look forward to hearing from you.

Cheers, Ben

 

[bertiebumblebee]

CHRIST Artemis - £150 quid for five litres -- sell it and buy a Stilo lol. I have a good digital meter to test the battery so no worries there. I have just looked at the offending ABS sensor and there is lots of corrosion under it. I know that when Peugeot ABS sensors get corrosion under them the corrosion pushes the sensor away from the ring and causes intermittent issues. To see if this was the same I decided to take out the sensor and clean all the rust away. You guessed -- siezed in solid and I have broken it getting it out. **BUGGER** I have ordered a new one and we will see if that sorts her out.

 

[Artermis]

I could see that one coming as I was reading through your post....

Soon as I read about deciding to remove it I was thinking "he'll be lucky, they never come out..." only to realise you'd found this out the hard way.

Don't know what it is about the way italians designed their ABS sensor setups but as you now know the only way they come out is very broken and in little pieces.

 

[dtimmins1985]

There is a trick to removing them

8mm open ended spanner, release spray (wd40 or plus gas).

Few nice sprays on the sensor and hub surrounding it and a little tap in the metal around the sensor should help to break it free a tiny bit then gently put the open ended spanner around the bottom chunky side of the sensor and wiggle it... should come free and gently prise it out.

I had all 4 of mine off when i rebuilt the front end suspension after the wheel snap indicident... didnt break any either... just think about it a little before attacking it or they will break!

 

[Davren]

There is a trick to removing them

8mm open ended spanner, release spray (wd40 or plus gas).

Few nice sprays on the sensor and hub surrounding it and a little tap in the metal around the sensor should help to break it free a tiny bit then gently put the open ended spanner around the bottom chunky side of the sensor and wiggle it... should come free and gently prise it out.

I had all 4 of mine off when i rebuilt the front end suspension after the wheel snap indicident... didnt break any either... just think about it a little before attacking it or they will break!

Mine needed a 14mm spanner.
.

 

[dtimmins1985]

What you running davren... mine may have been a 14mm spanner but from memory i had to scrabble around in the spanner tray that only contained spanners upto 10mm.

Wondering if there is different sizes or if its the same across the range.

Bear in mind that 150 multijet (m92) uses same hubs and suspension as the 2.4 abarth (well the hubs and shocks i know for sure).

 

[g8rpi]

I thnk you are both right, 8mm to remove the attaching bolt and 14mm on the flange to give it a wiggle and break it free. Don't pull on the cable.

Robert G8RPI.

 

[Davren]

What you running davren... mine may have been a 14mm spanner but from memory i had to scrabble around in the spanner tray that only contained spanners upto 10mm.

Wondering if there is different sizes or if its the same across the range.

Bear in mind that 150 multijet (m92) uses same hubs and suspension as the 2.4 abarth (well the hubs and shocks i know for sure).

Stilo MW JTD 115hp (2 of them)

I thnk you are both right, 8mm to remove the attaching bolt and 14mm on the flange to give it a wiggle and break it free.

I think it was 8mm hex key for the retaining bolts. Flash from the camera blurred out the size on the tool.

EDIT: Just found out while replacing the clutch that it's a 5mm hex key for the ABS sensor bolt, not 8mm as I posted above.
.

 

[dtimmins1985]

That sounds more precise.

I have similar photos on a memory stick somewhere... i used a similar tool to yours but it was shorter and i struggled to find a spanner to go over my hex piece nicley... now i remember why i was scrabbling around in the small spanner tray..

Should have done a guide. Used similar tools and clamps on drop links and also tiny spanners to wedge tapered slots.

 

[bertiebumblebee]

Thanks guys for the advice on removing the sensors without breaking them. I have cleaned up around the hole and fitted a new sensor. Now the corrosion behind the hub has been removed the new sensor looks to be closer to the abs ring than the old one. That was my theory of why it was an intermittent fault - the corrosion had pushed the sensor slightly further from the abs ring weakening the signal. As the sensor was broken getting it out I will never know for sure if it was that or just a faulty sensor. Anyhow all looks good now and fingers crossed that it stays that way. Thanks for all your help and suggestions