Help

[occgarv]

Battery is going flat all the time as the lights decide to turn themselves on - when car is locked, ignition key out etc. Car just out of warranty and has baffled all local mechanics - anyone any ideas

[Monster-Mat]

turn of the auto lights

[occgarv]

Even if the light switch is in off position and the key out they still come on - think it is more likely to be the auto light sensor?

[Steve ( West Mids )]

Have you tried covering the sensor ( on top of dash in front of driver ) and see if they coem on & off even in the lights off position?

[ColinBarber]

Cannot see how it is the light sensor. The ECU controlling it shouldn't be monitoring it if the ignition is off.

Sounds either like a problem with the ECU that controls the headlights (body ECU??) or the relay that operates the lights.

Has any of the wiring been tampered with? An alarm fitted?

[Steve]

also the magic question.. have you reset the ECU to see if it clears?

[Chris.S]

I have come accross several IS200's with this problem

Cause

Water ingresses the main fuse block under the driverside kick panel, thus causing a short circuit and the headlamps to come on without being switched on

Remedy

Replace the fuse block, which costs around £200 new.

[occgarv]

Having tried all the other suggestions already it sounds like Chris Shipley has the answer - will try and get fuse box and let you know. This has been driving me crazy for days so thanks

[Unregistered_User1]

Having tried all the other suggestions already it sounds like Chris Shipley has the answer - will try and get fuse box and let you know. This has been driving me crazy for days so thanks

If the car is just out of warranty, then Lexus should still honour the fix. It sounds like a problem which builds over time... not a sudden impact, so the problem probably started whilst your car still was in warranty. No harm in speaking to your dealer!

[occgarv]

Have already replaced fuse block and the problem has stopped. Mechanic does not think water got into the original one though. Anyway so far so good. At least I 'm back on the road.

[occgarv]

Well just when I thought I was out of the woods - its back to square one again - flat Battery this evening even after fusebox replacement - any other ideas?? Lexus in NI say they have never heard of this problem and are not accepting liability.

[mudzs]

was the flat Battery caused by the auto lights comming on again

[occgarv]

yes back to original problem

[mudzs]

I now it is not a complete solution but what about taking out sensers for the auto lights and rewiring so they are constantly off,might only be a case of joining two wires, could it not be the sensers at fault .

[occgarv]

will give it a try but at this stage I feel like setting fire to the whole car - this means ripping the whole dash out of course

[Steve ( West Mids )]

Do they come on in the day? If so could it be a short or something in the light switch ?

[mudzs]

Just a thought but have the auto lights got a seprate fuse would be easier to take this out.seems strange though that the system works with the ignition off ,is anything else live with it off

[occgarv]

there is no separate fuse for auto light - nothing else comes on - not the taillights just the head lamps - sometimes its 5 minutes after you get out of the car another time I thought I had it cured for 2 days but then it went on the blink again - its definitely not a short.

[ColinBarber]

It's not the auto light circuit. There is a problem with the main light circuit - probably water somwhere. Has the light relay been looked at/changed or the indicator/light controls and all the connector block?