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Join Date: Oct 2016
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I'm defeated... Headlight Woes!
As you may already know my car doesn't particularly like me.
I have rebuilt most of the front end of my car due to accident damage and when i started to take it apart the headlights worked fine.
When i put it back together they didn't.
I have had it on 2 OBD diagnostics machines now including taking it to an ex-BMW professional mechanic with the ISTA software etc. Neither of these readings really identified the cause of the fault, only confirmed there was one.
The car is simply showing up 2 faults....
The first is 'Cornering Lights Malfunction'.
The second is 'Dipped Beam Left Failure'.
When my friend put it on his iCarly BMW code reader it came up something to do with ACL Unit fault.
So i've now done some fault finding of my own to see if i can further identify the fault before I get it repaired.
First of all, I swapped the headlights round. The fault carried over with the left headlight.
I thought that narrowed it down to the various electronics on the headlight unit. Apparently not!
I started swapping over the various electrics to wait for the fault to carry over to the right. I switched bulbs first, then the control unit underneath, then the ballast.
Now, when I put the lights back in, the fault doesn't carry over. It remains on the left. All of the parts I am switching between the headlights are apparently working fine on the right side.
With the headlights as they are, either headlight works fine on the right side, but not on the left.
So I checked the fuses. I pulled every single blade fuse out of the car except the massive ones in the glovebox. All were fine.
So now i am literally at a loss.
Can anybody recommend a solution to this problem or at least another diagnostics route before I take it to BMW with the associated £100 per hour fees? I can do almost all the work myself for free if only I knew where this little electrical fault is!
Thanks in advance to all you helpers.
///M5 E60 Review in 2 sentences:
£1000 a month service costs, before you factor in the 9 mpg average. Then it's just the joyful enthusiasm it has for trying to kill you in any situation, or itself every other day.
'94 Renault Clio, '86 Peugeot 205, '97 Peugeot 106, '89 Nissan 200SX, '99 Peugeot 306 GTI-6, '01 Citroen Xsara, '07 Ford Mondeo, '06 BMW 335d E92, '06 BMW E60 M5