Technical Check engine light when entering a tunnel??

[Beaviz]

Hi,

My fiorino (2019 model) gives a blinking check engine, when entering a tunnel and goes in limp mode. Sounds crazy, but it happened to me twice. After cycling the contact, everything is ok. And I can drive with no problem.

It happened in the same tunnel, at exactly the same spot, the lowest part.

Could be coincidence, but feels not.

Just had it in for service, timing chain, pump an sparkplugs. Odb tells me misfire, but drives flawless all day, untill entering the tunnel...

Anyone tips on how to proceed?

 

[The Panda Nut]

I suspect this is coincidence. It could be slope related, but you need a diagnostic to find out what faults are stored in the ecu.

 

[Beaviz]

Taking a different route coming days, to be shure..
Will report back..

Thanks for your reply..

 

[Beaviz]

Yesterday a different route, no problems..

Today thrue the tunnel, no problems..

Only difference is, a full tank.
Maybe something with tank pressure or ventilation of the cap?

 

[The Panda Nut]

Could be. May be a slightly bad tank of fuel. I hope it stays OK.

 

[Beaviz]

Yesterday again, exactly same spot in the tunnel... Can't be coincidence now.. going back to the shop now...

Mechanic said, could be a electronic signal from the tunnel itself? Seems very unlikely to me, but can't rule it out