P0243 and P412 codes and management light and RPM gauge

[Dokter]

Hello, i recently bought a Smart. See my introduction in newbie section.

When I bought the car it had the motormanagement light on. I took the gamble because it drives and starts perfectly. I dont had any signs of powerloss or motor engine problems. However, when I diagnosed it with by OBD2 it sayd P0243 and P0412 error codes. It has something to do with the Turbo solenoide. Im familair with cars but not with this. See image below with the exact code (it is in Dutch):

https://ibb.co/nDMXkq

So as I said the car drives wonderfully but gives these errors. When i reset the errors the light goes off. I can drive exactly the same as with light on, and it wont light up again. However, when I turn the engine off and restart, the light turns on again and stays on for the time beeing until i reset it again with OBD. No difference in driving with light on or off.
I also found 2 loose connectors in the engine bay. I cant find the contra-connectors where they should be. See pictures.

https://ibb.co/hNPeWV
https://ibb.co/kBbF5q
https://ibb.co/c8amBV

This car is very fun and everything works well, therefore I didnt expect it to be somethng with the turbo and i took the gamble to buy the car. I hope it is something simple and not the end of a short ownership.

2nd problem:
THe RPM gauge doesnt move a bit. The clock works. The RPM gauge lights up just fine with headlights shifted on. What could this be.

Greetings and thanks

[Dokter]

Oh, and I have also got a vent which has been closed by rubber. On smart photos I see this shouldnt be like that:

https://ibb.co/gmX6dA

[mikerj]

P0243 Relates to the boost control solenoid (aka cycle valve), and one of those connectors should be attached to the solenoid valve. The valve is located in a very inaccessible location, on the back of the turbocharger air inlet pipe (known as the TIK pipe), FQ101 has some pictures showing the location. What year and model is your ForTwo, as some of the base models didn't have this valve fitted from the factory.

The P412 relates to the secondary air injection solenoid valve. This is an emissions system that blows air into the exhaust when a cold engine is first started, this gets the catalytic converter up to it's operating temperature more quickly. There should be a large valve on the right hand side of the engine, below the oil filler, with a hose connecting to an electric air pump that it mounted on the subframe on the right hand side, see this picture. This valve is vacuum operated, and the vacuum is controlled by a solenoid valve which connects to one of your spare connectors and to the blocked off pipe on the inlet manifold. Seems like someone has removed this which will be causing the code to light. You can ether buy a solenoid valve and plug it in to get rid of the code, or find out the resistance of the solenoid and connect a suitable resistor across the connector.

[Thrumbleux]

2nd problem:
THe RPM gauge doesnt move a bit. The clock works. The RPM gauge lights up just fine with headlights shifted on. What could this be.

Greetings and thanks

I think the needle is prone to losing its grip on its spindle. Worth checking before going further.

[Dokter]

P0243 Relates to the boost control solenoid (aka cycle valve), and one of those connectors should be attached to the solenoid valve. The valve is located in a very inaccessible location, on the back of the turbocharger air inlet pipe (known as the TIK pipe), https://www.fq101.co.uk/how-to-guides/fortwo-450/engine/181-fitting-a-cycle-valve"]FQ101 [/URL]has some pictures showing the location. What year and model is your ForTwo, as some of the base models didn't have this valve fitted from the factory.

The P412 relates to the secondary air injection solenoid valve. This is an emissions system that blows air into the exhaust when a cold engine is first started, this gets the catalytic converter up to it's operating temperature more quickly. There should be a large valve on the right hand side of the engine, below the oil filler, with a hose connecting to an electric air pump that it mounted on the subframe on the right hand side, https://static1.car.gr/5985195_1_z.jpg"]see this picture[/URL]. This valve is vacuum operated, and the vacuum is controlled by a solenoid valve which connects to one of your spare connectors and to the blocked off pipe on the inlet manifold. Seems like someone has removed this which will be causing the code to light. You can ether https://www.ebay.co.uk/itm/301981354816"]buy a solenoid valve[/URL] and plug it in to get rid of the code, or find out the resistance of the solenoid and connect a suitable resistor across the connector.

Thanks for the input! Will this be an easy fix and is the motor management light not big of a deal in this case? I understand that in summery the p0412 fault is fixed by putting the solenoid and it's connector back right?

And the p0243 is a bit more complicated, what should I do in that case to fix it? My smart is from 2003, it's the 450.

[mikerj]

Fixing the P0412 should be as simple as just plugging a solenoid valve in (assuming all the wiring is ok), though you will probably need to clear the existing fault code as well.

The P0243 might be more complex. If your car came without a cycle valve from the factory (50bhp "Pure" spec), then the ECU shouldn't be raising an error code if it's not fitted - in that case perhaps the ECU has been changed out at some point. Fixing this would require fitting a cycle valve, and ideally plumbing it into the wastegate actuator as per FQ101 web page.

If your car has a cycle valve already fitted then plug the connector in and see what happens (again you may need to clear the fault code). These cycle valves are notorious for failing, and the usual symptom of this is excessively high boost which makes the car go really well for a little while until the ECU protection kicks in after which the car performs very poorly. These valves are not particularly expensive for a new part, under £20.

[Thrumbleux]

If you are to be investigating the cycle valve, do yourself a massive favour and buy 1 metre of Diesel Spill Hose. Use this to replace the standard (very short) vacuum hoses connected to the cycle valve in lengths that permit all connections to made prior to refitting the cycle valve. Refitting a cycle valve with the standard short hoses is a PITA.

[mottofreee]

There are few devices that diagnose correctly and completely the Smart 450.
I kindly ask Tolsen to tell you more.

[ossy]

Hi Dokter, so you didnt visit Gerard !

[Dokter]

Hi Dokter, so you didnt visit Gerard !

Not yet, I didn't visit anyone. Just posted my question on multiple fora. Not going to do it myself. Gonna arrange it tomorrow.

[ossy]

If you know a little bit of the smart , it isnt a big thing to do.
But , if it is your first smart every thing is strange