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        General >> Problems >> Autobox Problem
        
(Message started by: pedro_pete on Mar 30^th, 2010, 1:08pm)

Title: Autobox Problem
Post by pedro_pete on Mar 30^th, 2010, 1:08pm

Hello everyone, my name is Pete. I hope you are all well.

I am new to this forum and I am sorry that my first post is a cry for help.
I have been the happy and relatively trouble-free, owner of my (R) reg 24v Ultima Scorpio for four years now. However, having recently passed the 90,000 mile mark I have been experiencing Autobox problems.

The first sign of trouble was an occasional reluctance to engage reverse gear. Revs would rise and eventually it would thump into gear with a bit of a jolt, sometimes selecting reverse would cause the engine to cut out completely.

This has since turned into a constant problem with both reverse and forward gears. Revs rise and then it eventually thumps into gear. This only occurs from cold start however, once up to running temparature the gearbox is as smooth as it ever has been.

From advice that I found on this website I checked the level and quality of the ATF. The level was just on the max and the oil when wiped on a white cloth appeared to be a pinky brown colour with no bits.

A mechanic friend, advised an oil and filter change. I purchased a filter kit from Ford Parts UK, including screen filter, gasket and o rings. My local Ford dealer advised me to use 3.5 litres of DP-M5 oil (it also had the numbers: 9U7J M2C919 AA on the bottles).

One oil and filter change later and... the same cold starting problems. A reluctance to select a gear, revving and thumping as before. Once up to temparature though, there is a distinct improvement, gear selection seems to be a lot more positive and kick down seems quicker to respond.
My mechanic said that the old filter was definately in need of replacement and that the old oil didnt look too bad, just well used.

I checked the new oil quality shortly after the change and it looked to be the same pinky brown colour as before. I have since been advised that as the torque converter holds a large amount of oil as well, the new oil will have just mixed in with the old again. I have also been advised to possibly change the oil a second time?

I was hoping that somebody could please give me some advice. Is my gearbox on its way out? or is it possible to save it. All help would be greatly appreciated.

Many thanks,
Pete.

Title: Re: Autobox Problem
Post by tonyboy on Mar 30^th, 2010, 4:05pm

Hello and welcome to the site. With torque converter and oil cooler it takes 10.3 Litres of oil, Check the oil level as described on the site ..... http://www.fordscorpio.co.uk/autogearbox.htm ... also it might be a good idea to clean the MAF...........

Title: Re: Autobox Problem
Post by Cosray on Mar 30^th, 2010, 4:06pm

Welcome pedro_pete -- are you Spanish?

Check your MAF first. Many topics on that here AND on the website. Read all about it!

That would be my first guess --
HTH
Ray

Title: Re: Autobox Problem
Post by Dave2302 on Mar 31^st, 2010, 1:19pm

What you are describing definitely sounds like low oil level, make sure you check the level with ENGINE RUNNING IN PARK and on LEVEL ground.

If not low level, don't bother wasting your money on oil changes it means the tranny is shot, but normally this would happen more when hot, from cold def sounds like low oil.

HTH Dave

Title: Re: Autobox Problem
Post by Cosray on Mar 31^st, 2010, 10:46pm

Pedro_pete -- I remember from my first Cossie it showed comparable behaviour such that you did not trust yourself in city-traffic because of the engine stalling and the gearbox bumping and jumping and kicking because of the revving engine...

Passengers would be rocked and shocked... turned out to be a partly worn engine-to-autobox loom. The one running from the front over the injectors to the autobox.

Once replaced the old one looked like Emmentaler cheese - holes, brittle sections, isolation missing and shorting... everything went back to normal after.

I understand these looms are still availbale though not cheap. I would advise you to inspect the wirequality of that loom.

If you search for [loom] on the website you will find plenty relevant hits where to look.

HTH,
Ray

PS Do follow this thread as well... sounds similar...
http://www.fordscorpio.co.uk/cgi-bin/yabb//YaBB.pl?board=Problems;action=display;num=1269469823

Title: Re: Autobox Problem
Post by Dave2302 on Apr 1^st, 2010, 11:47am

Yep, could well be,

The best way to diagnose this is a code read and if you have a "shopping list" of solenoids and sensors gearbox related then it's most likely a loom.

As said they are still available as long as you ask for "Fuel Cut Off Loom" which is what you wan't. Don't ask for Engine loom or they'll tell you it's NLA.
Should cost about £300.

HTH Dave

Title: Re: Autobox Problem
Post by pedro_pete on Apr 4^th, 2010, 11:10pm

Hello again, apoligies for the late reply.

Thank you all for your time and excellent advice, it has been greatly appreciated.
Following the advice of Dave, I checked the oil level again with engine running and in park. The level wasn't even on the Min mark.
After closer inspection by another mechanic, it turns out that the oil was leaking out. The leak has been fixed and the oil topped up, now registering between Min and Max markings. Left it over night to settle and tried it this morning, and, fingers crossed, the problem seems to have been solved! 100% improved from cold starting and changing better than I have ever known it to. No more revving, no more thumping into gear! Hurrah!

I'm genuinely over the moon, I love my Scorpio and was worried that it might have been curtains for it.

Once again thank you all very much for your help,
Pete.

Title: Re: Autobox Problem
Post by a900one on Apr 5^th, 2010, 1:22pm

Was it leaking on the oil cooler?.

Title: Re: Autobox Problem
Post by pedro_pete on Apr 15^th, 2010, 8:53pm

Hello again,

Well, it looks like I my have spoken too soon... :-/

I drove the Scorpio for the first extended drive last weekend since the oil and filter change. All was going well, it seemed to be driving bettter than ever. I decided to to test the car properly down a stretch of motorway and kicked down from 90 mph (I had to know if it could still do it). It kicked down as expected roaring into life, all seemed to be well.

However, after that something didn't quite feel right, almost like something had given way. Power seemed to have been restricted and when I reached 90 mph again the traction control light started flashing and I could feel the juddering under the accelerator pedal. It was almost as though the car was in some kind of safe mode.

I pulled in to some services and noticed that my transmission oil was spewing out of the bottom of the gearbox. I fortunately had some extra oil in the boot, which enabled me to limp home before i ran out completely.

I have not had the chance to investigate the cause yet. I had a minor oil leak fixed recently but it seems to have leaked from somewhere else. I was wondering if maybe the filter wasn't fitted or sealed correctly, I read another post on this forum about how they had changed the manufactured size of the filter and something about it needing a different sized bolt? I'm not sure if I've got the right tbh. Could this have been the cause?, I was unaware of this before having the work done you see.

Once again if anyone has any advice, it would be greatly appreciated.

Many thanks,
Pete

Title: Re: Autobox Problem
Post by Tompion on Apr 15^th, 2010, 9:16pm

The filter is within the box so if it doesn’t seal it won’t leak externally.
If the filter doesn’t seat correctly air can be drawn in and make the changes slow etc.

If the box overheats it can dump oil I believe, but whether air getting in with the circulating oil could cause it to overheat I don’t know.

Title: Re: Autobox Problem
Post by tonyboy on Apr 15^th, 2010, 9:43pm

Hello, the finnis code for the filter is 4000411, It's just the filter is a bit thinner and you may need some washers to pack it out, unless you snap it like i did, then i used a smaller 6mm bolt. but the physical size should be the same, .........

Title: Re: Autobox Problem
Post by Mike H on Apr 18^th, 2010, 8:18pm

Sounds like it's comng out under pressure. What about a hose leak?

Title: Re: Autobox Problem
Post by Dave2302 on Apr 18^th, 2010, 9:10pm

Sounds to me like it's blown the converter seal out of the front of the pump, happens a lot at speed.

The fact that it has been run with low oil probably damaged the pump bush, leading to this current faliure.

Dave

Title: Re: Autobox Problem
Post by tonyboy on Apr 18^th, 2010, 9:18pm

Does that mean a new seal or a new pump...........

Title: Re: Autobox Problem
Post by Jonnycab on Apr 20^th, 2010, 8:37am

Is the sump torqued up correctly ?.....I had an autobox leak a couple of months back & turned out the sump bolts were loose.

Regarding the trouble getting gear when the engine is cold....it could be the same problem as I (& a few others on here) have. As far as I know, the culprit is a sticking autobox reverse solenoid & only causes a problem when first started when cold (mainly in winter).

Mine's been doing it for about 3 years now & hasn't got any worse, & rather than an expensive strip down, I've learned to live with it. I find that when it happens, then turning off & restarting the engine 2 or 3 times seems to sort the problem :)

Title: Re: Autobox Problem
Post by Tekno on Apr 20^th, 2010, 10:49am

on 03/30/10 at 13:08:36, pedro_pete wrote:

The first sign of trouble was an occasional reluctance to engage reverse gear.

I would check gasget of reverse servo. If it's leaking, transmission can't get reverse engaged easily or it takes many seconds, because of low pressure. It's behind autobox sump bolted with 4 bolts and easy to find there. Also spring of servo would be good to replace. Or maybe whole servo.

http://www.ford-trucks.com/article/images/common_fix_4r55e_5r55e/common_fix_4r55e_5r55e_img_3.jpg

Title: Re: Autobox Problem
Post by pedro_pete on Jun 4^th, 2010, 7:39pm

Hello again, Sorry about the late reply but I've only just had the chance to get the Scorpio fixed.

Thank you once again for all of your helpful advice, however I am again calling upon your expertise.

My oil leak and gearbox trouble turned out to be caused by a faulty oil cooler. This has now been replaced and the leak is fixed and gears seem to be nice and smooth and positive whether from cold start or after running. So I'm pleased with all of that :-).

The trouble I have now is that when I am traveling at speed the traction control light is coming on at 90mph. It seems to be restricted/reluctant and it takes a few prods of the accelerator pedal to get it to go above 90mph.

I have tried cleaning the MAF sensor which is advised on this site. It hasn't solved this problem but has made a huge difference to the overall running of my engine, tick over used to quite lumpy but is now smooth and even. I will be doing this regularly from now on.

Just wondering if anyone else has experienced the traction control light and restriction at 90mph scenerio before. A friend at work said it might due to a rotation problem with one of the wheels or tyres? I have recently replaced one of my front tyres with a new one.

Could it be that there is a brand new tyre on one side and a worn tyre on the other side?

Could it be that simple or is it just wishful thinking?

Once again any advice would be greatly appreciated.

Many Thanks,
Pete

Title: Re: Autobox Problem
Post by Cosray on Jun 5^th, 2010, 7:30pm

Hi Pedro yes, I experienced similar behaviour once with one tyre out of 4 being worn, causing a significant unbalance from the sensors' input to the ABS processor at a certain speed, as in absolute sense the 4 inputsignals will diverge over a 'safe' threshold.

It predictably and correctly responded with a 'warning' signal to indicate that something in the wheeldata is amiss or not consistent.

Of course you could have the ABS-datalog read out by a well-equipped garage to make sure. Unbalance should show up immediately.

HTH,
Ray

Title: Re: Autobox Problem
Post by pedro_pete on Jun 5^th, 2010, 8:20pm

Hello Ray,

Thank you for your reply, I'm glad to hear that it isn't anything too serious :-). I've got a 400 mile trip to Cornwall coming soon, so I'm hoping to get the Cossie in top form for the trip. It's by far the BEST car I have ever owned for eating up the miles in total comfort.

I will get the wheels and tyres checked ASAP.

Thanks again,
Pete

Title: Re: Autobox Problem
Post by Mike H on Jun 7^th, 2010, 3:18pm

In other words, because say the two rear tyres are slightly different diameter, due to uneven wear, this produces mis-matching speed measurements from each wheel?

Title: Re: Autobox Problem
Post by Highlander on Jun 7^th, 2010, 3:38pm

Traction control light would point to a problem at the rear rather than the front.

I'd have a very close look at the rear wheel bearings before you attempt 90mph again ;)

Title: Re: Autobox Problem
Post by Tekno on Jun 7^th, 2010, 3:41pm

Front abs sensor connectors can have massive amount of sand inside them. I removed them and soldered wires together. They are now also easy to measure and keep more clean.

Title: Re: Autobox Problem
Post by Cosray on Jun 7^th, 2010, 7:58pm

Yes Mike H, it does and it should. Each ABS-sensor generates a digital stream of one's and noughts when turning and when these do not match within say 10% ? of the others the ABS processor decides to sound the alarm and light the LED.

Therefore Highlanders suggestion to have a good look at the rear bearings is valubale. Once they start sqeaking or chirping it's too late.

Here's a bit of text on the subject:

http://www.fordscorpio.co.uk/abssystem.htm

Go to section FAULT --- SUGGESTED ACTION => ABS Light goes off etc. etc.

HTH,
Ray

Title: Re: Autobox Problem
Post by Mike H on Jun 8^th, 2010, 6:26pm

Fussy innit? http://livinginthepast-audioweb.co.uk/kbf/surprised.gif

Title: Re: Autobox Problem
Post by Cosray on Jun 8^th, 2010, 6:43pm

on 06/08/10 at 18:26:47, Mike H wrote:

Fussy innit? http://livinginthepast-audioweb.co.uk/kbf/surprised.gif

Which part , Mike H?

RAy

Title: Re: Autobox Problem
Post by Mike H on Jun 8^th, 2010, 7:41pm

ABS processor I presume

Title: Re: Autobox Problem
Post by Cosray on Jun 8^th, 2010, 8:01pm

on 06/08/10 at 19:41:18, Mike H wrote:

ABS processor I presume

Nothing fussy about that! Just an old tired processor comparing the timing of 4 signals... if one sensorsignal comes in slower than the other - meaning its wheel is slippin' an' slidin' - it will release the brakes on that wheel... and so on 4 times in a row, very quickly. So you won't have to pump your braking pedal... and dream on being safe.

HTH,
Ray ;-)

Title: Re: Autobox Problem
Post by faffi on Jun 8^th, 2010, 9:41pm

Still, you can really feel the ABS system on the Scorpio is of a very old generation. Regulation is very slow, which makes braking distances very long. And if it is really icy on the road, you actually risk the rear overtaking the front if you don't get off the brake soon enough.

The biggest let-down with the 2004 Mondeo I now have is that it's ABS is barely better than that of the Scorpio. Most modern cars will stop incredibly rapidly on dry road also with the ABS system working due to rapid cycling, but these Fords takes much longer to stop with the ABS than without, unfortunately.

Title: Re: Autobox Problem
Post by Cosray on Jun 8^th, 2010, 10:02pm

Dear faffi -- the longest and most disturbed and frantic reaction delay routing is between the situation - your eye - your poor paleontically old overworked brain busy visually processing, comparing, doing risk management and deciding - your spine - your right foot.

Everything else - hardware, software - is lightning fast, compared. Your ABS slow speed theory holds no water and is of no significance at all in the situation.

It will perform regardless if you are aware of it, which cannot be said of the brain.

Over to you, Ray

Title: Re: Autobox Problem
Post by faffi on Jun 8^th, 2010, 10:37pm

Not saying I would be without - I'm simply saying that compared to current systems, it's not very good. Back when Ford introduced this ABS system (1985?) there was a magazine doing tests with and without engaging the ABS. And the test driver beat the ABS even on ice (and by a lot in the dry) - although with practice and without experience anything panicking. So it is a safety enhancer for the odd situations where you mess up. I just wish it was better ;)

Title: Re: Autobox Problem
Post by Cosray on Jun 9^th, 2010, 3:49pm

Faffi, here's an article on ABS with interesting references, which support your thoughts.

http://en.wikipedia.org/wiki/Anti-lock_braking_system

http://www.racv.com.au/wps/wcm/connect/Internet/Primary/my+car/car+safety/safety+equipment/brakes/ABS

Enjoy,
Ray

Title: Re: Autobox Problem
Post by Tekno on Jun 9^th, 2010, 5:48pm

I've tested scorpio with and without abs on dry tarmac. with abs it stops clearly quicker... on wet, gravel and ice its vice versa

Title: Re: Autobox Problem
Post by faffi on Jun 9^th, 2010, 7:23pm

Thanks for the links - although I was familiar with most of what was written, it was new to me that ABS would do so much worse on slippery surfaces. That's entirely opposite to motorcycles, where ABS outshines non-ABS by a significant margin when it's slippery, but only rarely does the ABS match the non-ABS in the dry.

I am pretty certain that on motorcycles, the ABS reads how quickly each wheel is retarding (and frankly, I thought this was the case also with cars) and if it slows too quickly, it means it is about to lock up and pressure is released. The development between the BMW bike system of 1988 and today is massive, however, and today they are the best stoppers in the business. Honda has opted to go for slightly less than maximum braking in order to keep their bikes level and make absolutely sure they won't sommersault. Others, like Yamaha and Ducati, have the ability to topple over forward if there is enough grip, requiring a very alert and skilled rider to maintain control. For very experienced and good riders, the BMW has the best system. For 95% of the population, Honda's system is superior because it doesn't require the rider to think or react other than squeezing the brakes.

My main concern with the Ford system fitted to the Scorpio and the Mondeo is the slow cycling - you can hear it go thump-thump-thump. Another design fault is early onset - they ABS starts to regulate before the tyres are out of grip. At work, we have a 2005 Toyota Yaris, and I have driven it for nearly 3 years from time to time, and only this winter did I realise it was ABS equipped when it softly came in and assisted while braking on black ice.

One thing that I find hard to understand, is that people actually get startled enough to release the brakes in a panic situation when the ABS kicks in. I normally just keep the pedal to the floor and let the system do its job - although I have begun to release and reapply in slick conditions with my Ford because the ABS simply cannot get the car stopped effectively enough - just as stated by the article.

Title: Re: Autobox Problem
Post by Cosray on Jun 9^th, 2010, 10:36pm

Faffi, motorbikes' wheels + tyres may have a considerably less mass.

Also, the mass of the total vehicle to be stopped is probably... what half of that of a car? As I am sure the decelaration curve follows a square law these smaller masses may be a significant factor.

As a result, even a comparable system may respond much sharper on a bike than on a car, as the rotating mass has less inertia and subsequent forces are smaller.

What do you think?
Ray

Title: Re: Autobox Problem
Post by Mike H on Jun 11^th, 2010, 7:07pm

I dunno either of my Moto Guzzi's wheels are easily as heavy as a car wheel. Have carried a Scorp wheel up to the tyre place at top of our street but not sure I fancy carrying one on the MG's wheels any great distance. Mind you that's with the discs still bolted on as well.

Problee near enough right about overall weight, once you get two bods on and certainly with luggage as well.

on 06/08/10 at 20:01:22, Cosray wrote:

Nothing fussy about that!

Ahem, praps I should mention that was a joke. ;D Originally

Title: Re: Autobox Problem
Post by Mike H on Jun 11^th, 2010, 7:50pm

Appendix ~ on average a motorcycle has only one eighth the rubber contact compared with an average modern car (wider tyres and all that), not a half as you might imagine cos it's only got half the number of wheels.

If either wheel locks you're usually thrown off straightaway (especially the front). So detecting onset of wheel lock suddenly becomes a very important consideration.

My Scorp handbook only says ABS allows you to steer around an obstacle while braking, not specifically that you'd be able to stop in a shorter distance than without ABS. Also it warns slippery conditions still require great respect.

Title: Re: Autobox Problem
Post by faffi on Jun 11^th, 2010, 8:33pm

In a straight line, locking up the front tyre on a motorcycle is no problem as long as you don't slide too long - I often lock up the front, especially in the wet, on purpose to to feel the limit and make sure I release as I should. While leaned over, however, locking up a wheel can quickly land you on your ear.

Motorcycles and cars stop in about the same distance, but messing up doesn't have the same negative impact in cars.

Title: Re: Autobox Problem
Post by tlundkvi on Jun 11^th, 2010, 9:40pm

on 06/11/10 at 19:50:45, Mike H wrote:

My Scorp handbook only says ABS allows you to steer around an obstacle while braking, not specifically that you'd be able to stop in a shorter distance than without ABS. Also it warns slippery conditions still require great respect.

I believe this is the right way to see ABS.

I think shorter breaking distance is one of the great misconceptions with ABS. ABS reduces breaking power to get better control of the car in these situations, locked wheel will always stop faster because of the friction, but the car will only steer when the wheels are rotating, simply speaking. Good tires will cut breaking distance quite remarkably too.

Regarding slippery condition, couldn't agree more. Everyone knows the pump-the-brakes theory from the driving academy (we steered around an imaginary elk on a track covered with ice and snow in Finland :)), but when in the real situation most are likely to panic anyway, hence the need for ESPs, ABS etc.

Title: Re: Autobox Problem
Post by faffi on Jun 11^th, 2010, 11:03pm

on 06/11/10 at 21:40:58, tlundkvi wrote:

locked wheel will always stop faster because of the friction,

Locked wheels will never stop the vehicle quicker on any form of firm surface. In deep snow or gravel, perhaps, but not on asphalt of slick ice etc.

Title: Re: Autobox Problem
Post by Mike H on Jun 12^th, 2010, 1:44pm

I am reminded of many years ago my driving instructor (was a long time ago!) was rammed in the side by a 4x4 failing to stop coming out of a side road on packed snow.

The driver was like "But I was in 4 wheel drive!"

My instructor was like "And that makes a difference because?"

LOL http://livinginthepast-audioweb.co.uk/images/misc/laugh.gif

Title: Re: Autobox Problem
Post by Tekno on Jul 5^th, 2010, 8:58pm

I'm too having now problems with automatic gearbox

When it should shift no next gear, it just raises rpms and then after couple secs it kicks it in..

I also get P0171 "Too Lean" codes..

here's obd analysis: http://ruohoranta.fi/singapore/galleries/sekalaiset/idle2.PNG

Title: Re: Autobox Problem
Post by Mike H on Jul 6^th, 2010, 12:22pm

Have you tried it with MAF unplugged?

Title: Re: Autobox Problem
Post by pedropedro on Jul 6^th, 2010, 3:55pm

for what its worth on mine which has this problem if you keep a/c on that increases the load on the engine and shifts will be better.. also if you select winter mode it starts in 2nd and again bigger load and shifts better

Title: Re: Autobox Problem
Post by Tekno on Jul 8^th, 2010, 11:29am

I cleaned MAF and now it's better but not perfect. MafV's are 0.9 and 0.7 at idle. Don't know which is correct

Title: Re: Autobox Problem
Post by Mike H on Jul 8^th, 2010, 5:44pm

0.7 I think.

Try driving it with MAF unplugged anyway. ;D

Title: Re: Autobox Problem
Post by Tekno on Jul 8^th, 2010, 6:40pm

compared to without maf, WITH MAF connected it feels kinda sluggish or spongy, like always waiting for me to press accelerator more.. gearshifts are very sharp though :D

Without MAF it starts to speed up immediately and no waiting.

here's after second cleaning: http://ruohoranta.fi/singapore/galleries/sekalaiset/Scorpio-98/idle4.PNG

Title: Re: Autobox Problem
Post by Mike H on Jul 8^th, 2010, 6:56pm

Oh-kay, back to the original issue, does the gearbox behave more normally do you think while MAF is unplugged?

Title: Re: Autobox Problem
Post by Tekno on Jul 8^th, 2010, 6:57pm

yes absolutely no "slipping/rpm raising"

I wonder why there is two voltages for MAF in obd software

Title: Re: Autobox Problem
Post by Mike H on Jul 8^th, 2010, 8:40pm

Ah-ha!! Right so.

We-ell, I thought OK well a new MAF sensor is like >£50 from buypartsby so go for it see if a brand new one makes a difference, and it did. I guess these things do wear out, though you'd think there's nothing to wear out.

Not sure about the question though

Title: Re: Autobox Problem
Post by Cosray on Jul 8^th, 2010, 8:59pm

Yes Mike. Not only in Scorpio's.

My friend Willem the other day was stopped by his own Jeep's engine management going into LOS because one tyre was down to halfpressure - would not let him drivefaster than 20 MPH - apparently the manufacturer, being afraid of claims, has this behaviour programmed into the ABS which then directs his engine management to speedlimits...

In Scorpio's ABS will detect a permanent diff in wheel rev's and generate a fault code.

Ray

Title: Re: Autobox Problem
Post by Mike H on Jul 9^th, 2010, 9:34am

That's great, so instead of being able to stop safely on the hard shoulder with a puncture, you're rammed up the back by an artic in the middle lane http://livinginthepast-audioweb.co.uk/images/misc/huh.gif

Title: Re: Autobox Problem
Post by Mike H on Jul 9^th, 2010, 9:37am

on 07/08/10 at 18:57:17, Tekno wrote:

yes absolutely no "slipping/rpm raising"

OK so that proves there's nothing wrong with the box after all. I've also been down the road of considering getting a 2nd hand one, which wouldn't have solved it

Title: Re: Autobox Problem
Post by Cosray on Jul 9^th, 2010, 12:04pm

on 07/08/10 at 20:40:08, Mike H wrote:

Ah-ha!! Right so.

I guess these things do wear out, though you'd think there's nothing to wear out.

Yes they do wear out. It's basically a filament made of resistance-material with a higher temperature-coefficient and yes, those properties change over time.

Here's a nice write-up about the subject, explaining its operation and possible specification-shift, unbeknownst to the EEC-V.

HTH
Ray

Title: Re: Autobox Problem
Post by Mike H on Jul 9^th, 2010, 12:37pm

Yep a heater resistor, and downstream, a thing called a thermistor (I imagine that's most likely what it is), the former can change value due to heat stress, the latter can just get tired and cease to adequately cover its full range of resistance values.