Headlights coming on after car is switched off

[Shivers]

After I switch of the yaris after a while the headlights/daytime running lights switch themselves on flattening the Battery.  Can anyone help please?

[Auris James]

Has it got auto lights? If so sensor on windscreen may be faulty? Can you put switch in off/non auto position. Do the headlights come on still?

James👍

[flash22]

it could be the follow me home lights it will turn off after 2-3 mins, does it do it, with the lights set to off ?

[Shivers]

Hello and |Thanks for your reply.  Its a 2015 1.3 I don`t now if it has auto lights its my wifes car.   It does it when everything is switched off.  Flattens the Battery.

 

[flash22]

Key or push button start ?

do you get the key warning if you turn the car off, leave the key in the ignition then open the door

do the interior lights work ?

[Shivers]

Key start interior lights work

 

[Starensis]

I’d have a guess at Body Control module fault ( water ingress or similar ) or ignition relay.

[Shivers]

Is there an OBD reader I can get to find faults. Where is the Body Control Module please, Thanks all who are helping.

[Shivers]

It has not got auto lights and is key start, interior lights work.

[Starensis]

We had a 05 plate and had water ingress in passenger footwell. Body panels had not been sealed during Manufacture. BCM is normally on A post: relays, in fuse box under bonnet.

Ignition relay though may be inside under dash. 
 

I’m sure someone with a bit more knowledge than myself could pinpoint them.

[Shivers]

Just checked car for water ingress, can`t find any.  Changed headlight relay but problem still there.  Complete mystery.  Garage wants 150 pounds to check the car.  I am on a pension and can`t afford it at this time of year.  Many Thanks again all who are helping.  You are a great bunch here.

[Starensis]

Ignition relay or headlamp switch?

[Shivers]

Thanks Starensis I will get an ignition relay tomorrow and try that solution. 

[Starensis]

11 minutes ago, Shivers said:

Thanks Starensis I will get an ignition relay tomorrow and try that solution. 

Do headlights come on even though headlamp switch is in off position? Are you sure it’s headlights coming on?

[flash22]

The lighting is ecu controlled, do the lights stay on or do they turn them self on after the leaving the car - if you have auto lights it will have "Auto" on the stalk

 

First thing to do is get the Battery checked (Most places will do this FOC), the cold will reduce its capacity and or kill a weak Battery, if the voltage drops below a certain voltage it can make the electronics do weird things

If it's on its original Battery, it's at the end of its life, especially due to lock down, replace it with a Bosch s4/s5,Varta or Yuasa

[Shivers]

The lights turn off.  When I lock car, and after a while the lights turn on intermittently and flatten the Battery.

[Starensis]

It can only be ECU/Module. Think column switch creates earth circuit to module, which in-turn activates headlamps from module. I'm sure someone will correct me if I'm wrong.

[Shivers]

Thanks all who helped with this problem you are all a great help.  It turned out to be a knackered Battery.  Fitted new Bosch this morning and thankfully problem sorted.  

[Cyker]

Glad you got it fixed! Thanks for letting us know!

 

On 12/12/2021 at 3:46 PM, flash22 said:

First thing to do is get the battery checked (Most places will do this FOC), the cold will reduce its capacity and or kill a weak battery, if the voltage drops below a certain voltage it can make the electronics do weird things

Can't believe you called this correctly! I would never have guessed a dying Battery could make the headlights turn *ON*!!  

 

[Catlover]

Another candidate for the weird and wonderful club.  👍😀

[flash22]

Ah the wonders of modern technology, given the age of the car and OP's location, and the first of the very cold snaps

 

or it could just be Occam's razor

The principle gives precedence to simplicity: of two competing theories, the simpler explanation of an entity is to be preferred. The principle is also expressed as “Entities are not to be multiplied beyond necessity.”