Technical Issues with fiat 500 engine light

[Amethyst4]

Warning light is back on. Code shows P0106. I have disconnected the blue wall re and the evap is suctioning as soon as engine is turned on. Does this mean it is faulty and needs replacing?

Leave the electrical connection on

Turn the engine on

Wet your finger and put it over the now exposed end

There shouldn't be any suction felt

99 out of 100 it's the only test needed as the normal failure mode is being jammed open from a bead from the evaporation container jamming open, if this fails you might have to flush the evap system to stop the new solenoid also getting trashed

You can do the same test with the electrical connector also removed there should be a slight suction felt this time

This would prove it's opening and closing correctly but not if the ECU is commanding it probably

Assuming these are okay you can double check by blocking the pipe and taking it for a few test drives,

If there's now no problems you can order a solenoid in confidence

I only know of a couple where some other work has been carried out and the whole solenoid hasn't been clipped back in properly

If the problem persist we need to do further diagnostics

I would not think you don't have an earth

p0101 and p0106 both a mismatch in pressure reading at the MAP sensor

There's quite a few possibilities, brake servo hose, inlet manifold distortion

View attachment 458524

Thankyou, so when I checked again with electrical port still connected, suction was felt immediately.
How is the evap system flushed and would this be done with the old solenoid connected please?

 

[jackwhoo]

Plug the open black tube part of the solenoid valve . Leave blue pipe open.
Drive car for week to make sure problem doesn't reoccur , if problem doesn't reoccur replace evap solenoid valve.

 

[koalar]

Warning light is back on. Code shows P0106. I have disconnected the blue wall re and the evap is suctioning as soon as engine is turned on. Does this mean it is faulty and needs replacing?

Yes its faulty

Tap over the end and make sure normal drivability has returned,

They normally fail due to bits of charcoal from the canister jamming them open

I'd disconnect the other end of the pipe and blow down the pipe into some kitchen roll, if it comes back clean your good to change just the solenoid

If there's bits of charcoal in there we will have to revaluate the situation

 

[Amethyst4]

Yes its faulty

Tap over the end and make sure normal drivability has returned,

They normally fail due to bits of charcoal from the canister jamming them open

I'd disconnect the other end of the pipe and blow down the pipe into some kitchen roll, if it comes back clean your good to change just the solenoid

If there's bits of charcoal in there we will have to revaluate the situation

Only problem is that in my fiat, the solenoid is difficult to get to. Could just about reach the blue wire and the electrical cable but the other side is fully covered so wouldn’t be able to do this test.

What do I put on the end of the solenoid to plug it and could it cause damage if this blue wire is disconnected for a week with the solenoid plugged?

 

[koalar]

It's safe to leave the blue vent pipe off

Just not good for the environment, vapours vent to the atmosphere instead of being burnt

It's how all cars use to be

I'd just tape over the end with electrical tape