canbus led 501 bulbs bring on error light

[johnm]

I just fitted led canbus 501 bulbs in the side lights of my x250 and front marker lights the markers are ok but the error light comes on with the side lights, any advice welcome.

[Derek Uzzell]

It might be useful to know what make/model/year of motorhome you own, but I’m guessing from your reference to “marker lights” that it’s a ‘coachbuilt’ design and that the marker-lights are the high-level type.

 

Assuming that’s correct, the marker-lights will have been installed when the X250 chassis was converted into a motorhome, so replacing the original marker-light bulbs with LED equivalents should have no negative impact on the electronics of the X250 chassis.

 

However, replacing the original halogen side-light bulbs with LED equivalents is potentialy problematical, as the X250 chassis electronics will ‘see’ the LED bulbs and - because these draw so much less power than the halogen originals - may well ‘consider’ that bulb failure has occurred and illuminate the relevant dashboard warning-light.

 

LED 501 bulbs are marketed that claim to be “CAN-bus compatible” (example here)

 

http://www.autobulbsdirect.co.uk/501-Twenty20-Cree-LED-12V-W5W-Canbus-Wedge-Bulb.html

 

but I’ve no hands-on experience of whether these would actually stop an X250’s dashboard warning-light from being triggered. If the LED bulbs you’ve used were sold as being CAN-bus compatible, but the dashboard warning-light still illuminates, either X250 electonics dislike all LED 501 bulbs retrofitted in side-lights, or just dislike ‘your’ LED 501 bulbs. Suggest you contact whoever sold you the LED bulbs about this and - in the interim - put the original halogen bulbs back in the side-lights.

 

This MHFun discussion touches on the CAN-bus issue

 

http://www.motorhomefun.co.uk/forum/threads/sidelight-problem.68060/

[StuartO]

I looked at the spec for the LED lamps mentioned in the previous post and while they are not supposed to trigger CANBUS warning lights these are said to be significantly brighter than ordinary 5W halogen side lamps and under "Tech Spec" they are marked "for off road use".

 

This may mean they would offend some aspect of the Construction and Use Regulations because they are too bright.  LEDs as side lights should fail less frequently but although they would use less power, this is unlikely to make a significant contribution to fuel consumption, so I would suggest that on a CANBUS vehicle designed for halogen lamps, you stick with ordinary halogen bulbs.

 

[Derek Uzzell]

This 2012 discussion may be of interest regarding ‘legality’

 

http://www.vauxhallownersnetwork.co.uk/index.php?threads/using-led-sidelights-white.334766/

 

Within the UK it’s going to be The Road Vehicles Lighting Regulations 1989 rules that should apply, but these will have been based originally around filament bulbs.

 

If an LED 501 bulb is not “E”-marked, it’s (probably) illegal to fit it to a vehicle, and it may well be illegal to replace an original fiament bulb with an LED equivalent (or vice versa) even if the LED version is “E”-marked.

 

The only certain way of ensuring legality would appear to be to fit replacement bulbs that exactly match the technical specification of the Original Equipment bulbs.

 

 

[hallii]

The Canbus LEDs are supposed to give the same load as the original bulb. Usually with resistors, thus negating any power saving but fooling the computer into thinking there are still bulbs in circuit.

 

It is not unknown for foreign manufacturers to get things wrong or "forget" certain components. Then they don't work as they should.

 

H