What sort of masochist buys a Smart with a broken autobox?

[scaryoldcortina]

 

Here we go again! I can't seem to resist stuff that no-one sane would touch at all, so when I was offered this low miles Smart ForFour for very little money because it's stuck in gear and won't start I jumped at the chance.

 

Aside from the obvious problem that I had to take the spark plugs out just so I could put it in the garage it isn't too bad - recent tyres, long MoT, 57k miles and very clean and tidy. Just broken...

 

Ran the codes, it has 23 stored codes but an almost flat battery so I cleared them (after printing them off, obv) and put the battery on charge for the night. They are almost all of the type "No message/CAN fault/intermittant" but there are also a few permanants including "Implausible transmission adaption data" and "Current gear is implausible" which both point to either the gear selection assembly or the gear indicator.

 

I'll dig into it tomorrow, I already looked for damaged wiring and waterlogged ECUs but it all looks OK so far. Annoyingly I don't seem to have (and can't find on the internet) any pinouts or wiring diagrams so I'll be probing blind but that's nothing new either.

[Lacquer Peel]

An upgrade* for your son?

[Captain Furious]

Sounds an interesting challenge, could well be a simple electrical fault and easy win. nice acquisition

 

Although we know from wheeler dealers that ALL automatic transmission faults are fixed by a fluid and filter change.

[hairnet]

Be like crazy Germans and put hayabusa in it

[Dave_Q]

I do sometimes wonder what they're thinking when they write these fault codes.

 

Gear is implausible?

 

What gear is being reported? 12F? Chicken Vindaloo?

 

Surely if an actual gear is being reported, that's a pretty plausible thing for a gearbox to report, even if its the wrong one?

[loserone]

It's a lovely colour.  Is is SO WRonG?

[cobblers]

I do sometimes wonder what they're thinking when they write these fault codes.

 

Gear is implausible?

 

What gear is being reported? 12F? Chicken Vindaloo?

 

Surely if an actual gear is being reported, that's a pretty plausible thing for a gearbox to report, even if its the wrong one?

 

 

It'll be reporting being in two gears at once, or no gears at all etc etc. There'll be a sensor per gear and it's only expecting one to be actuated at a time, something along those lines.

When we test ECUs at work, they'll throw a fault code for "boost level implausible" if you turn the boost sensor up to 10psi with the engine at idle etc etc.

[scaryoldcortina]

It's a lovely colour.  Is is SO WRonG?

You know what I saw in the plate? SOS 4 WRG.

 

Mayday had the plate WRG616A before I went and got an age related.

[SiC]

What sort of masochist buys a Smart with a broken autobox?

You aren't the only one! How similar is it to the getrag box that's in mine?

 

I'll dig into it tomorrow, I already looked for damaged wiring and waterlogged ECUs but it all looks OK so far. Annoyingly I don't seem to have (and can't find on the internet) any pinouts or wiring diagrams so I'll be probing blind but that's nothing new either.

I'm suffering that in mine too. Evilution site has some hand made ones but not that detailed. I believe they're all on the Mercedes Star diagnostics system setup. Are any available on the Mercedes website for independent repairers?

[scaryoldcortina]

You aren't the only one! How similar is it to the getrag box that's in mine?

Entirely different - it's the same mitsubishi box as the manuals and Colts get but with an automated selector head and clutch actuator.

[UltraWomble]

Entirely different - it's the same mitsubishi box as the manuals and Colts get but with an automated selector head and clutch actuator.

Which made me think....

£100 and jobbed

[scaryoldcortina]

I thought that too, but wrong generation colt and would be a massive shame also.

[phil_lihp]

I like these and that's the best colour combo, quite rare now too I reckon, on the basis I haven't seen one in forever.  Fingers crossed it's a simple fix.

[scaryoldcortina]

I must admit, the silver/gold combo is rather nice, and it does remind me of £8 car.

[SiC]

I guess you've seen this?

http://www.evilution.co.uk/Engine/forfour_auto_gear_fault.htm

[scaryoldcortina]

I had, that's not the same fault. Mine is flashing "O" on the display and is clearly stuck in a high gear. The clutch actuator seems ok, I already had a quick look.

[Kiltox]

SoC and SiC both have knackered Smarts

 

Good luck gents.

[Guest Hooli]

Smart cars, not smart owners obviously

[robthedonkey]

I spotted this locally.... Then read gearbox fault and ran away

 

Sent from my ONEPLUS A3003 using Tapatalk

[Tamworthbay]

I know a guy on another forum, let's call him 'Ian' for arguments sake, who was involved in designing the gearbox operating system on these. He is a grade A cunt who thinks he knows everything about everything. So please feel free to post up any areas you feel it's design is defective and I will gladly pass them on.

[sporty-shite]

Entirely different - it's the same mitsubishi box as the manuals and Colts get but with an automated selector head and clutch actuator.

How big a deal to get rid of the electronics and convert to manual?

 

Not that this will happen, because you'll have it sorted within the week!

[Pillock]

Convert it to a Sturmey-Archer three speed.

[cobblers]

I think that's essentially what they are. Inside the "ecu" there's some spinning weights like a governer on a steam engine which pull on the cable the faster they spin.

[scaryoldcortina]

 

Shift motors off, everything looks OK. Both motors work, no missing teeth and I managed to get the car back into neutral. Next job is to remove the gear indicator, box down for that bit.

[twosmoke300]

Is it's an automated manual like the jazz I shit ?

Remember the clutchless smiley transit ?

[scaryoldcortina]

Yeah, that's exactly what it is!

 

Anyway, the indicator switch thing seems fine too

 

 

Probing the connections reveals it to be two potentiometers, both read from 1k to about 3k then a 10 deg patch with no connection. Only fits back on the shaft one way so not possible to get wrong (but fiddly to put back!)

 

it goes here..

 

 

which is why you need to drop the box a bit to get it out.

 

Now it's time to reassemble, attach a fresh battery and see what happens.

[Sigmund Fraud]

Crikey, I've spent years thinking that all this modern electrickery is black magic, but seeing it taken apart methodically by someone who knows what they're doing makes it almost seem straightforward !

 

Is there a "Modern car electrics/electronics for Neanderthals " type book around ?

[Guest Hooli]

 

 

Is there a "Modern car electrics/electronics for Neanderthals " type book around ?

 

Write it yourself by taking pics as you take it apart. Because they cheat & put everything fancy in the ECU it's often simpler to work on the actual thing these days as there are just a few sensors not loads of 'gubbins'.

 

For example on a proper engine you have a dizzy with weights & a vacuum thingy in, wot you turn to set the timing & maybe points to adjust. On a modern you've got coils plugged onto the plugs & a sensor on the crank & cam shafts.

[Vince70]

Smart seems to be the new Renault on Autoshite at the moment..

Top buy and I love the colour.

[scaryoldcortina]

It's back in bits again because the motors and the selector drum sensors have to line up - the motors also have a position sensor each so it was all still implausible.

 

Thing is though, something is up because the tech data I have (and I'm reading live data from the car) say that neutral should be somewhere other than where it is. This might have something to do with the fault - it's reading about 30deg away from where it should be.

 

Sensor off again next - the inside ring looks easy to get wrong....