Hi, i have an ford focus 1.6 tdci, that has start-stop button, with a strange problem, so when my lights are on, the engine doesnt stop when i press the button. If i turn switch to 0 (off) at lights and pressing the stop button, then the engine stops.
When i press stop button with lights on, like all dashboard lights comes up (like turn on ignition).
Some said that to check if a light is burned, checked all, it isnt, maybe you can give an advice what or how to check ?
Is strange when i press stop button, with lights on (and here doesnt stop), and i turn off the lights (switch on 0), the engine stops (omg)..
PLEASE ANY HELP ?

Sounds like it might be a feature to stop you from forgetting to turn your lights off. Not sure about the whole dash lighting up though.

What model year is it?

2 minutes ago, SamDalton said:

What model year is it?

my guess is 2010

34 minutes ago, unofix said:

my guess is 2010

exactly

Still waiting for any help 😄

11 minutes ago, NorbertCristian said:

Still waiting for any help

We all just assumed that the car would have run out of diesel by now and the engine would stop 🤣

So the most likely cause of the problem is water getting in to the Body Control Module (BCM), which is part of the passenger compartment fusebox. The lighting circuits are controlled by the BCM and on cars of your age there is an issue with water causing corrosion of the connectors and the circuit board, causing random faults with lights, wipers, screenwash, reverse lights and even issues with the ignition circuit.

Start by disconnecting the negative lead from the battery. Then get to the fusebox/BCM and start removing all the connectors. Look for any signs of water and any greenish corrosion of any pins in the plugs or on the circuit board.

26 minutes ago, unofix said:

We all just assumed that the car would have run out of diesel by now and the engine would stop 🤣

So the most likely cause of the problem is water getting in to the Body Control Module (BCM), which is part of the passenger compartment fusebox. The lighting circuits are controlled by the BCM and on cars of your age there is an issue with water causing corrosion of the connectors and the circuit board, causing random faults with lights, wipers, screenwash, reverse lights and even issues with the ignition circuit.

Start by disconnecting the negative lead from the battery. Then get to the fusebox/BCM and start removing all the connectors. Look for any signs of water and any greenish corrosion of any pins in the plugs or on the circuit board.

Hmm, i was thinking is a switch problem but i will check this also, thanks 😄

On 11/5/2022 at 3:39 PM, unofix said:

We all just assumed that the car would have run out of diesel by now and the engine would stop 🤣

So the most likely cause of the problem is water getting in to the Body Control Module (BCM), which is part of the passenger compartment fusebox. The lighting circuits are controlled by the BCM and on cars of your age there is an issue with water causing corrosion of the connectors and the circuit board, causing random faults with lights, wipers, screenwash, reverse lights and even issues with the ignition circuit.

Start by disconnecting the negative lead from the battery. Then get to the fusebox/BCM and start removing all the connectors. Look for any signs of water and any greenish corrosion of any pins in the plugs or on the circuit board.

So i have take out whole BCM, theres no corrosion, not any error code, no nothing, any other ideea ? 😄

Are you using a generic code reader to check for DTC's ?

On 1/4/2023 at 8:16 PM, unofix said:

Are you using a generic code reader to check for DTC's ?

Im using Autel diag. software. and no error shown about ignition, or headlight.., just heated mirror are not working, open circuit, that doesnt cause the problem.

Guys, i did it, it was a DRL fuse, not blown, but was there, and should not been there bcz i dont have DRL, so i have removed it. Now works perfectly.