[coachivan]

This has happened twice. Normal driving no problem then low fuel light blinks. Turn off car light stops blinking. Within 5 minutes CEL ELECTRONICS comes on. Codes P0455, P1420, P1525 and P1533. Clear codes and within days same thing has happened. I know what all the codes mean but what would cause this K40 relay? BTW car always runs perfect as far as I can tell.

 

[Kajtek1]

Would be nice if you could find codes meaning from the stickies, so we don't have to do your homework.
Try to flip gascap gasket to start.

 

[TurboDieselPower]

Typically the low fuel gauge light blinks when the evap system suspects the gas cap is loose hence the P0455.

The other codes a Benz specific and I don't know them off the top of my head.

-TDP

 

[coachivan]

OK low fuel lamp blinks then after I stop and restart the ELECTRONICS warning and cel comes on. Is it possible the gas cap can really cause this P0455 to be reset? How about I take the gas cap off completely?

 

[brandon671]

If you take off your gas cap completely wouldn't it definitely throw a code

 

[Musikmann]

If you take off your gas cap completely wouldn't it definitely throw a code

Yes it will and should cause a blinking CEL too.

 

[Kajtek1]

What would be a difference for tank pressure sensor between leaky cap and no cap?
Sometimes the obvious things are the hardest to notice.

 

[coachivan]

Yesterday the low fuel light started blinking I decided to just keep driving for about another hour. The cel ELECTRONICS did not come on until after I shut the engine off. The cel ELECTRONICS came on right away. Only 1 code P0455 (evap emission control leak gross leak detected). I put a new fuel cap on today so we shall see if the problem is solved. Would the next item to suspect be the charcoal canister?

 

[coachivan]

Update. New fuel cap installed. Yesterday the low fuel light came on NOT BLINKING. After stop it turned off. No codes. Ran fine the entire time is this fixed?

 

[Musikmann]

In my opinion, you fixed your issue.

 

[kwhombre]

Flashing Fuel Light and CEL

OK low fuel lamp blinks then after I stop and restart the ELECTRONICS warning and cel comes on. Is it possible the gas cap can really cause this P0455 to be reset? How about I take the gas cap off completely?

Had the exact same problem after a fill-up. A day later I got a flashing low fuel light on a full tank. This happened twice. The third time, the CEL light came on and then the flashing low fuel light.

Happily I found the above post, checked the gas cap and the station attendant had not put the cap on completely until it clicked. Reseated the cap, checked the codes (there was a 0455), cleared it and now all is well again.

Thanks for saving me a trip to the mechanic.

 

[Canyon Mike]

This has happened twice. Normal driving no problem then low fuel light blinks. Turn off car light stops blinking. Within 5 minutes CEL ELECTRONICS comes on. Codes P0455, P1420, P1525 and P1533. Clear codes and within days same thing has happened. I know what all the codes mean but what would cause this K40 relay? BTW car always runs perfect as far as I can tell.

First thing to try is just retightening the gas cap. I had the same problem and that solved it.