ChrisBarnes

Some bulb failure warnings are caused by faulty or loose eathing connections to various light clusters or fittings. If you consistently get warnings about a specific bulb and it appears to work fine, check the earthing points in the immediate area for tightness or corrossion. I had random left rear fog bulb failure, and I found a loose slightly corroded earthing connection behind the left hand boot liner. Cleaned this up and tightened the nut and all the bulb failures disappeared. Bulb failures indicate a lack of current getting to a bulb, either because the bulb itself has failed or the connections cannot deliver the current to the bulb, either directly or returning via the earth connections.

I had an intermittent bulb failure warning that was driving me insane. It turned out to be a loose earthing point nut in the left hand side of the boot behind the left hand boot liner. The earthing nut was very loose and corroded a little due to water laying there for a while due to the infamous Octavia rear wash wipe motor leaking water into the boot and surrounding areas every time I operated the rear wash/wiper. After I cleaned up the connectors and tighted the earthing nut, I have not had any more problems or bulb failure messages.

LED bulbs should last for years. A quoted MTBF (Mean Time Between Failures) value of 50000 hours means that a bulb used 8 hours a day should last for over 17 years. Might be a lot less in a car with moisture, vibrations and other factors, but you get the idea. But LED's are destroyed by two things, too much current, and heat. LED's bought for cars should not die due to current as they are rated for use in 12V systems. Only if the system is generating voltages above this value will too much current flow in the led. Too much current causes internal overheating of the led, and it eventually melts itself and stops working. I have successfully installed 5W cree LED festoons into the number plate lights and have no problems. To correct the bulb failure warnings I had to solder a ceramic 10W 75 ohms resistor to pull the missing current not pulled by the led bulbs. These bulbs are very bright and stand out, compared with the standard bulbs. I also checked and found an earth wire from the left rear light cluster to earthing point behing left hand boot liner was loose at the nut, and corroded a bit. Cleaned this up and tightened earthing nut, and all now ok. Had intermittent bulb failure warnings before I solved this. Worth a look at all earthing points in the area for loose or corroded ones. It may be possible that an intermittent connection to the leds is causing voltage spikes that eventually cause the led to breakdown internally and fail.

Could you help me code it Simon. I have VCDS and have walked along the long coding bytes of module 09 (J519) looking for a bit to toggle or byte to set, to switch it on, but cannot work out which one it is. I am happy to experiment, but would like some insight if you have done this before. Thanks for your help .... One other question: Why is the left fog light not enabled for use in the UK? Regards Chris

Is there any way to get the left rear fog light to work by modifying or reprogramming the j519 module. I was convinced it worked when I first got hold of the car a year ago.

I have a problem with my 2009 1Z Octavia TDI VRS left rear fog light that is driving me nuts. I had a bulb failure warning a few months back for the left rear fog light. No problem, I'll replace it. On inspection the bulb was ok. I removed the left boot internal trim and saw the earth nut with the brown wire from the light cluster was very loose and starting to rust a little. I cleaned all this off and secured the earthing wire and nut. Checked continuity from light cluster earth pin to body, and all ok. I expected the fog light bulb to work at this point but no. The voltage on the lignt cluster blue/white fog light line was 1.87V and only as bright as side lights. I hooked up VCDS and started to investigate. The output to the fog lamp shows as 12% for the rear right and 96% for the rear left.??? Surely this is the wrong was around. The rear left fog light is the one that doesn't work. I removed the rear left fog light bulb and the car reports a rear left fog light error in the maxidot display, and when I replace it the error is not shown. I have swapped bulbs, interchanged the left and right light clusters and nothing makes the fog light bulb on the rear left light up. I removed battery connection and unplugged the Voltage Control Module J519 BCM plugs. I checked continuity between plug AA pin 6 and the Blue/White wire on rear left light cluster, and all is ok. So I thought the BCM was faulty. I bought a replacement secondhand BCM of the exact same type and model, and recoded it to the same BCM as the original unit using VCDS, which was accepted. I even individually checked each byte of the coding and adaptation values to make sure it's all exactly the same. Tested the fog light and it's the same problem, no left rear fog light lit, but rear right fog light working ok. VCDS stating that Rear Right fog light is 12% and rear left fog light is 96%. I think this is a software bug with VCDS 12.10. Now I cannot believe that two BCMs have exactly the same fault on them. I am completely at a loss of how to fix this "simple" problem, so please throw any ideas my way as I need some inspiration on what to do next. I really do not want to buy another BCM from Skoda at £253 each. Any ideas ? Regards Chris J519 BCM info ------------------ Address 09: Cent. Elect. Control Module Part Number: 1K0 937 087 Component and/or Version: BCM PQ35 H 020 0358 Software Coding: 48180AB89041B1C04008008011000124010000AE424D81605C4440000000 Work Shop Code: WSC 73430 VCID: EED8F9D23940936EED9 Advanced Identification Identification: HRE-HER Revision: 00020000 Date: 22.11.08 Manufacturer number: P401 Test stand number: 1429 Flash Status Programming Attempts(application): 0 Successful Attempts(application): 0 Programming Status: 00000000 Flash Date: ----.--.-- Flash Tool Code: 00000 000 00000 Software BAP: 01.04.00 Diag: 01.00.01 CAN: 01.43.00 TP 2.0: 03.04.00 KWP2000: 03.00.00 OSEK-OS: 04.02.00 OSEK Net: 03.69.01 LIN 2.0: 02.07.00 Misc. Hardware number: 1K0 937 087 Workshop System Name: J519 VCDS Info: Labels: 1K0-937-08x-09.clb