Thread: Led trailer on a D4 my13

The issue is that the D4 is constantly sending signals around the harness to check status of the car and these cause the LED trailer lamps to flash constantly. (Just watch out for other people's trailers with LED and you'll soon see what happens.)

Also the D4 needs to read the resistance across the globes so that it knows that the trailer is connected, it then disables the reverse sensors and enables trailer stability control.

Originally Posted by Lotz-A-Landies

The issue is that the D4 is constantly sending signals around the harness to check status of the car and these cause the LED trailer lamps to flash constantly. (Just watch out for other people's trailers with LED and you'll soon see what happens.)

Also the D4 needs to read the resistance across the globes so that it knows that the trailer is connected, it then disables the reverse sensors and enables trailer stability control.

Oh ok this is all new to me I towed a trailer in the weekend with LEDs but did not notice the lights flashing but did notice that the rear sensors where still operating didn't think much of it at the time. What happens when the trailer stability control kicks in?

Plenty of discussion on this topic

http://www.aulro.com/afvb/d3-d4-rrs/...er-lights.html

A recent software upgrade was supposed to fix this.

I can now run led brake lights, led park lights ok but when either left or right blinkers are engaged, both blinkers blink like hazard lights being on....trailer light does not come on either.

Previous to the software upgrade, all lights would flicker....they almost have it right.

I still use the pulse box to make it work properly.

Brett.....

Originally Posted by the_amors

Oh ok this is all new to me I towed a trailer in the weekend with LEDs but did not notice the lights flashing but did notice that the rear sensors where still operating didn't think much of it at the time. What happens when the trailer stability control kicks in?

Same as with normal stability control, apart from the D4s computer making calculations based upon sensor readings with the known factor of the trailer on the rear.

You have to be driving behind the car/trailer combination to see the LED lamps all flashing independantly

I thought you merely needed a resistor wired across the LED lights to make all functions work.

Also, I though stability control was completely independent of the trailer. That is, even if a trailer is attached and the computer does not know about it, it still attempts to rights any wriggle irrespective of the trailer attached to it because it can sense the vehicle being pushed about by G forces which don't align with speed, wheel rotation and direction of travel.

I'm interested in the topic because I am waiting on delivery of a trailer with LED lights myself. I went to talk with the trailer manufacturer about it. The whole issue appeared to be a complete mystery to him. Doesn't fill me with a sense of confidence so I'm prepared to just sort it myself when I get the thing.

I have one of the plug in types of resistor units because not all my trailers have LED lamps (the ex-military Haulmark the only LED one) the only really important factor is that without the resistor unit the reverse sensors sound when you try to reverse.

Surely that is enough reson to get one, also I'm not modifying the wiring by having a plug in unit.

I bought mine off ebay from a bloke on the central coast for half the price of the one from Moss vale.

If you connect your trailer plug without car running it will disable the reverse sensors . If car is running when plug is connected they dont disable, at least thats how it works on mine. Now i just have to work out how to get trailer stability assist light to work. Any clues?