Technical The one and only Dualogic failure thread

[jaahn]

Hi nad87
My suggestion would be this. Reading the codes and finding none is good news but not enough. You should get a person with the correct software, MES or Fiat, to do a re-learn of the clutch takeup. This can be a magic fix and make the car sooo smooth which it will do if there are no mechanical problems. Do it soon before it causes more problems. At the low miles your car has done that should be all it needs.
Jaahn

 

[jrkitching]

I am the new owner of a 2019 Fiat 500 Dualogic 1.2.

Hi and welcome to the forum.

How long have you had it, and do you have any remaining warranty cover on the car?

At the low miles your car has done that should be all it needs.

I'd agree; even by the standards of this thread, it's a low mileage to be having major problems. I'd still like to see it get checked over properly by someone with the right diagnostic software who knows what they're doing. Just plugging a generic code reader into the OBD2 port is unlikely to tell you what you need to know. If those miles were done in heavy London traffic by an unsympathetic driver, then anything is possible.

If a clutch relearn fixes this issue and everything else checks out, you should have reasonable confidence in it for the next 30k miles at least. After that, as the numerous posts in this thread indicate, owning a dualogic beyond 50k carries a definite additional risk over a manual car, and that might be a good time to give serious consideration to its replacement.

when setting off, its quite jerky/judders.

On reading the OP's description of the problem again, are we even sure this is actually a clutch/transmission fault? The 1.2 can be a bit spluttery and hesitant when pulling away; this sometimes happens if the plugs are past their best, which is quite likely at this mileage if they're the original ones.

As the OP has said it's more noticeable when starting from cold, I'm moving toward thinking this may not acutally be a fault with the dualogic system.

If this were my car and the plugs were the original ones, changing them would be my next step.

@jackwhoo, Well spotted. If it looks like this is more likely to be engine related than a clutch/transmission issue, I'll move it into a separate thread.

 

[nad87]

Jaahn

Thank you very much to the both of you for your insight.

How long have you had it, and do you have any remaining warranty cover on the car?

I have had it for a month and I have no warranty.

plugs

I believe the sparks were changed in 2020 at 4k miles.

I took it today to my local mechanic who used a maxysys machine to relearn the clutch. No faults codes are stored. I thought it did in fact improve slightly. Having started the car once fully cold it seems to again hesitate but not as much as it first did when setting off. Its like a continuous jump before it sets off. once warm again the symptoms get less. Gear changes up and down are fine. It is just that initial set off. Im thinking of changing the sparks and coil pack tomorrow.

 

[Paul112004]

What would cause a pump to run but not actually pump any fluid and the pressure sensor only says 3bar

Do you think its the accumulator and because it's not presurizing the pump has trouble pumping fluid

If i undo the pipe or the sensor fluid pumps out so it does pump but just doesnt do it when everything is tightened up

New pump and clutch bleed does nothing I've done clutch bleed so many times now

There is plenty of fluid also

 

[Greener2023]

Where is the pump located or fuse? Thanks

 

[Lucid]

Hi all, I've never owned a Fiat, but I'm contemplating buying a new 500 - I'm looking for a small second car that will do around 5000km per year, maybe less. There's lot's of boring options, and the 500 looks very cool. However, I've learned about the transmission problem and ended up here. A couple of questions I'm hoping someone can answer - (1) In 2023, do you think Fiat have done anything to improve their transmission, or do we still have to budget for a new gearbox at 50K? And (2) how prevalent do you think the problem is? Does every Fiat 500's transmission cough and die at 50K, or is it more like a problem that affects a small percentage of the fleet? Thanks!

 

[richie17]

Hi all, I've never owned a Fiat, but I'm contemplating buying a new 500 - I'm looking for a small second car that will do around 5000km per year, maybe less. There's lot's of boring options, and the 500 looks very cool. However, I've learned about the transmission problem and ended up here. A couple of questions I'm hoping someone can answer - (1) In 2023, do you think Fiat have done anything to improve their transmission, or do we still have to budget for a new gearbox at 50K? And (2) how prevalent do you think the problem is? Does every Fiat 500's transmission cough and die at 50K, or is it more like a problem that affects a small percentage of the fleet? Thanks!

(1) Probably not, it was discontinued in Europe 3 years ago, so is only available in a few very small markets these days. (2) I think it has a lot to do with how it's driven and cared for. So if you're buying new and look after it, shouldn't be a worry. Based on what you say, it would be 10 years old even if it did fail at 50k, anyway.

 

[Lucid]

(1) Probably not, it was discontinued in Europe 3 years ago, so is only available in a few very small markets these days. (2) I think it has a lot to do with how it's driven and cared for. So if you're buying new and look after it, shouldn't be a worry. Based on what you say, it would be 10 years old even if it did fail at 50k, anyway.

Thanks, that's interesting - I didn't know it had been discontinued in Europe. I gather Europe is electric only now? The 500e is arriving here in New Zealand soon, but it's priced very similar to a Tesla Model 3, i.e. you'd have to be a real Fiat fan to buy one.

 

[SvenDt]

I have solved the problem of dropping from 5th to N myself, it took long time so I'll share what I know.
Off course, first make sure that you have the correct oil level and the pump builds pressure as it should. Then It's a fairly easy fix !
The main culprit, withe other things being fully operational, is so called "stop" solenoid. It changes the movement of gear selector shaft between 1-2 , 3-4 and R-N planes.
View attachment 418031
After you unscrew it, there is a spring loaded nipple which, when activated, protrudes into the barrel behind it to generally block the internal plane seletion barrel :
View attachment 418032
The problem is that the internal mechanism is oiled and greased, over time gunk gets under the nipple and further into the solenoid, causing it to stick. The spring is not strong enough to push back the solenoid shaft quickly, this is why sometimes people cannot engage any gear for a couple of minutes after dropping to N -it needs time. The lower the outside temp, the more likely this can happen - greasy gunk being thicker.

option 1 - quick fix - It should be possible to reach and unscrew the solenoid - 500 offers less space than my Lancia Musa , but it should be possible after removin battery holder plate. Put some foil beneath so as not to drop screws, spring and nipple. Put the car in N first. Screws are phillips , there is no pressure in this part of robot. Tighten back with care.
Clean the solenoid by slowly spraying something like WD40, then brake cleaner, rubbing alcohol etc over the little shaft, let them drop sink inside. Do it many times in turns until the shaft moves fairly freely. The liquids will drain through plug assembly. Apply brake cleaner as final, give time it to evaporate, you can even heat it up to make sure it's dry inside. At first, you might need to use a 9v battery with two cables to pop the shaft back out.Don't worry about polarity. New solenoid is pricey and there is no need to change it if it works.
While solenoid is out, also clean the nipple socket in the barrel from any old grease to prevent it from sticking.

View attachment 418033
View attachment 418034

Option 2 : Full, long term fix is to take the robot out and clean the whole "barrel" inside and then re-grease it with high quality, wide-temperature-graded synthetic grease . You can see this being done here:

screenshot:
View attachment 418035

Option 2 best made by a mechanic, unless you really know what you are doing, followed by factory calibration in MES

Of course, there might be some other underlying issues. Then it needs to be properly diagnosed and possibly overhauled.Find a mechanic whoe deals with dualogic.
Hope that Helps.

I have actually done a complete overhaul of the robot myself, it is quite a durable and bulletproof device with just a few soft-spots. It requires all components to work properly, with very little margin for error and then it will serve years on.

Greetings ET Alien,

You mentioned you have done a complete overhaul on the robot? May I ask if this included the replacement of internal seals such as the clutch rod o-rings and gear selector shaft seals?

Thanks for reading,

Sven

 

[PedroC]

Hi All,

I’m new here but seem to be having a slightly unique problem with my daughter’s 500c Dualogic.

We purchased the car and all was fine, carried out full service, new brakes etc and all was good.

After having the cam belt and aux belt replaced we developed a problem with clutch overtemperature warning coming on after 5 miles or so of driving.

Mechanics took the car to an auto specialist who reprogrammed everything and said it should be fine. A few days later if came back with clutch overtemperature again. We were given an estimate of £3k to replace clutch and seals on gearbox which they said was leaking. We declined and I collected the car.

I took the car to another reputable auto specialist who read the codes which were P2912-98 clutch sub system. Can’t find any better info anywhere about that particular code. Anyway it also showed brake fault and voltage issues with start stop temporarily disabled, he suggested fitting a brake light switch and check the battery. It turned out it had the wrong battery and the brake switch was indeed faulty. These were both replaced. Car drove much better and had significantly more power ( assume brake switch causing issue) however, after 10miles clutch overtemperature.

The guy recommended a new clutch which was fitted with new fork, bushes and seals were checked with no leaks, turned out selespeed unit had new accumulator and sensors fitted in end of 2021. All reprogrammed and driving like silk but still coming up with clutch overtemperature warning.

I decide to get Multiecuscan and the leads and have a look myself. I’m reasonably competent with a set of spanners and like to problem solve.

On scanning the car I found the P2912-98 code and an over voltage on a circuit for the BCM, I cleared the faults and none showed again. I scanned all the modules and not all were able to connect, airbag showed a failure to connect as did IPC did a little searching and found that earthing could be the problem.

I started by checking the earth connections to the engine and gearbox, these were corroded and loose. I stripped and replaced these with new and went over the engine bay and interior cleaning and reseating the earths. This seemed to work wonders ,on turning the key the whole dash lights up with every pre start check light and all cleared on starting. All modules present on Multiecuscan and all showing no faults.

New problem is now the car selects neutral,first or reverse and drives in motion gears but will not go up through the box, it just stays in first. If you try to operate manually it says operation not admissible.

It allows the service final calibration and shows correct in the status however when you start the car it immediately operates the clutch several times as if doing a clutch drain and then will only select first, neutral or reverse and the status of the self calibration changes to not completed.

Has anyone got any ideas ? It seems like an electrical gremlin to me but how do you trace it when there are no fault codes and everything says that is has full functionality. Could it need a new TCM? This will have been reprogrammed dozens of times now.

Any help will be greatly appreciated.

Thanks in advance.

 

[jrkitching]

I’m new here but seem to be having a slightly unique problem with my daughter’s 500c Dualogic.

Sorry to hear about your problem.

How old is the car, how many miles has it covered, and how long have you owned it?

 

[jrkitching]

I scanned all the modules and not all were able to connect, airbag showed a failure to connect as did IPC did a little searching and found that earthing could be the problem.

Another potential cause of seemingly random electrical gremlins is a failure in the wiring loom, specifically at the point where the loom passes through the rear hatch.

This has caused airbag connection problems in the past.

I'd suggest inspecting this closely; you'll need to release the grommet and you might need to roll back some of the insulating tape. To avoid any risk of further electrical damage, disconnect the battery before you do this.

It's a simple check which will cost you nothing.

 

[PedroC]

Another potential cause of seemingly random electrical gremlins is a failure in the wiring loom, specifically at the point where the loom passes through the rear hatch.

This has caused airbag connection problems in the past.

I'd suggest inspecting this closely; you'll need to release the grommet and you might need to roll back some of the insulating tape. To avoid any risk of further electrical damage, disconnect the battery before you do this.

It's a simple check which will cost you nothing.

Thanks for the reply and for moving the post to the correct thread.

This car is the convertible model so doesn’t have the hatch although I’m sure there is wiring to the boot lid for the lock release and number plate lights. I’ll check this and have a careful look around the loom for any possible issues.

Thanks again.

 

[Ify1988]

Hi

I am new to the forum and looking for advice, I have 2017 500s dualogic with 80k miles. When starting the car from cold get a ticking and squealing noise from the gearbox area. Once the car has been driven for 5-10 mins noises dissappear. Doesn't have any problems selecting and changing gears, any ideas what this could be ? Does the ATF fluid need changing.

 

[John202020]

Hi

I am new to the forum and looking for advice, I have 2017 500s dualogic with 80k miles. When starting the car from cold get a ticking and squealing noise from the gearbox area. Once the car has been driven for 5-10 mins noises dissappear. Doesn't have any problems selecting and changing gears, any ideas what this could be ? Does the ATF fluid need changing.

Hi welcome, no doesn't need ATF fluid, the reason being your car actually has a manual gearbox with a standard clutch but uses a robot to do the changes for you.
Any noises are not good maybe other members will be along to advise.

 

[jrkitching]

Hi

Hi, and welcome to the forum

I am new to the forum and looking for advice, I have 2017 500s dualogic with 80k miles.

It's all pretty much been said in this thread already.

This is the sort of mileage at which these transmissions are often problematic. Finding anyone with the skills to repair them is challenging. If it fails outright, your options are going to be both limited and expensive. If you can get the car to one of the very few independent garages that actually understands these transmissions, they may be able to offer meaningful advice. Without seeing the car, all anyone here can realistically do from a keyboard is speculate. I'd suggest the best way forward would be to get any fault codes read & run a clutch wear diagnostic program (and perhaps a clutch relearn). That will need a Fiat-specific diagnostic tool (most generic code readers will be useless here). If this shows the clutch is wearing out, but there are no other obvious faults, then change it. If it shows anything more serious, I'd not want to put any more money into this car.

I would not personally want to own any Fiat with a dualogic transmission beyond 50k miles. If it were mine, I'd be giving serious consideration to trading it in whilst everything is still working.

Out of interest, how long have you owned it?

 

[aidanc94]

Hello,
Like many others, I am new here, my partner and I share a 2013 500 twin air, recently it suddenly disengaged gear on a freeway and refused to go back into gear. A few cycles on and off fixed this and on we went.
A few weeks later I park the car and suddenly smoke comes from the transmission with a burning smell and wont go into gear at all. Tow it to a local mechanic who advised clutch was burnt and needed replacing, $2500AU. Once the new clutch was in, the actuator wouldn't calibrate. Towed to a fiat specialist now who found a blown fuse an relay on the pump electrical circuit, replaced the fuse and relay and the pump won't receive power. Connected the pump to an external power supply and it powers on. Currently taking the vehicle apart for the second time now to try and find the electrical fault $3000AU down the drain and counting.

Anyone have any ideas or tips I may be able to pass to the mechanic? They are an alfa/fiat specialist and deal with these all the time.

 

[jrkitching]

Hello and welcome to the forum.

Condolences. I'm sorry to hear about your problem.

A few weeks later I park the car and suddenly smoke comes from the transmission with a burning smell and wont go into gear at all. Tow it to a local mechanic who advised clutch was burnt and needed replacing

That diagnosis fits the symptoms, but

$2500AU.

seems a very high price to pay a local mechanic (ie not main dealer or fiat specialist) for just a clutch replacement (around £1300 UK equivalent).

And they didn't properly repair your car. I'm not familiar with consumer protection legislation in your country, but I'd be asking them for some/all of that money back.

They are an alfa/fiat specialist and deal with these all the time

At least it's now in the best place for getting to grips with whatever is going on. I don't see how anyone sitting at a keyboard halfway round the world can advise you better on what's wrong than a local specialist with the car in front of them.

As you'll likely have gathered from reading some of the other posts in this thread, the sad reality is that a 10yr old 500 dualogic with a major transmission fault may not be economically repairable.

 

[Jussi69]

Hello all - I have a question about the relays for dualogic.
T20 30 Amp - Start Prevention with Robotized Gearbox
T30 50 Amp - Dualogic Gearboxinterlocking Pump
T31 30 Amp - Front 12v Power Supply

Can anyone share more data so I could order these relays online as I currently dont have access to the car.

sometimes when the car has been parked overnight the pump does not prime when opening the driver door - resulting N. A couple of restarts and the robot wakes up. So could be the relays and as they are not expensive in general, I could try to replace them first.

 

[aidanc94]

Hello and welcome to the forum.

Condolences. I'm sorry to hear about your problem.


That diagnosis fits the symptoms, but

seems a very high price to pay a local mechanic (ie not main dealer or fiat specialist) for just a clutch replacement (around £1300 UK equivalent).

And they didn't properly repair your car. I'm not familiar with consumer protection legislation in your country, but I'd be asking them for some/all of that money back.


At least it's now in the best place for getting to grips with whatever is going on. I don't see how anyone sitting at a keyboard halfway round the world can advise you better on what's wrong than a local specialist with the car in front of them.

As you'll likely have gathered from reading some of the other posts in this thread, the sad reality is that a 10yr old 500 dualogic with a major transmission fault may not be economically repairable.

We got a discount at the first mechanic, the specialist found the electrical fault, the circuit had fried itself which they managed to repair, they then said the selespeed accumulator was leaking (we could have gotten away with not replacing it, but we decided to replace it) and the selespeed unit had oil all over it and the solenoids, they cleaned it all up and cleaned the inside of the solenoids which they said can cause it to go into neutral.

Car back now, going ok except every now and again when it downshifts from second to first it jolts and stalls, generally after about 40 minutes of driving, does it twice, I restart the car each time and it works, has anyone had this issue before? Ill be calling the mechanic today to see if they can shed any light.