Trailer light malfunction error message

[MattG]

Having changed my 13 pin Euro towing plug to a 7 pin flat plug and installed a Redarc Tow Pro Elite electric brake controller (with diode kit), with the headlights turned OFF, the trailer lights and electric brakes all work as expected. When the headlights are switched on, although the trailer lights and brakes still all work as expected, a warning light comes on in the heads-up display and a "Trailer Light Malfunction" warning message appears on the centre display. As all of the lights in our trailer are LED lights, I suspect this is a CAN BUS error related to the much lower resistance associated with LED lights. Has anyone else experienced this error? I'm hoping that with enough consumer pressure, Ineos might get to work on a software patch. If our LED trailer lights are the cause of this issue, it seems strange that Ineos haven't thought about this already, given that most modern trailers have LED lighting as standard.

 

[21DFND]

I also changed mine to the 7 pin. The 13pin plug has a cable for the left and right side rear lights which need to be connected with one way diodes into pin 7 , I also connected the reverse cable with one way diode into the some pin as I would get a reverse light fault with the trailer plugged in when reversing.

 

[Mikeb62]

Yes, exact same happened to me. I also have LED lights on my trailer.
Solved by installing a load resistor across brake-light and earth wires. This "Narva Load Resistor 21W 12V 90034BL" or similar. I think is a common problem, not just with Grenadier.
I also, as above post, put diodes on the two tail-light wires into one tail-light wire for Australian trailers.

 

[pedrogb]

I was just contemplating how to sort this problem.
My Grenadier was converted to 12 pin plug before I bought it, and I have the same issues with my LED lights on camper and box trailer, both 7 pin. Everything works, just get the warning lights when lights are turned on or into reverse.
I did the responsible thing and went to my trusted auto electrician. He said it was a common problem, and made me a 12 pin to 7 pin adapter. I didn't pay for it, he told me to test it first.
When I plugged it into my car (it was running at the time) it immediately began to smoke. I quickly disconnected it, and returned it, they told me they would look into it, but I have heard nothing since, so I think I'm on my own.
Your photos are excellent, I'm happy to have a go at changing from the 12 pin to a 7 pin, if someone could show me a close up of how the diodes are wired in,
I'm not asking for anything too fancy, maybe a diagram, my assumption is the side and reverse lights into one wire, into the diode, then into the pin 7 socket. That's what it looks like in the above photos. I also don't know which way is which with a diode.
I didn't quite understand what Mikeb62 said about the resistor across the brake light and earth wire in his last post
Thanks

 

[MattG]

I was just contemplating how to sort this problem.
My Grenadier was converted to 12 pin plug before I bought it, and I have the same issues with my LED lights on camper and box trailer, both 7 pin. Everything works, just get the warning lights when lights are turned on or into reverse.
I did the responsible thing and went to my trusted auto electrician. He said it was a common problem, and made me a 12 pin to 7 pin adapter. I didn't pay for it, he told me to test it first.
When I plugged it into my car (it was running at the time) it immediately began to smoke. I quickly disconnected it, and returned it, they told me they would look into it, but I have heard nothing since, so I think I'm on my own.
Your photos are excellent, I'm happy to have a go at changing from the 12 pin to a 7 pin, if someone could show me a close up of how the diodes are wired in,
I'm not asking for anything too fancy, maybe a diagram, my assumption is the side and reverse lights into one wire, into the diode, then into the pin 7 socket. That's what it looks like in the above photos. I also don't know which way is which with a diode.
I didn't quite understand what Mikeb62 said about the resistor across the brake light and earth wire in his last post
Thanks

I second the request for a detailed diagram or set of instructions as to how/where the load resistors are installed and any information on the type of diodes used and where they should be installed. I’m keen to solve the problem of the trailer lights error message if it is as simple as it sounds. Anyone able to help? Cheers

 

[MattG]

Yes, exact same happened to me. I also have LED lights on my trailer.
Solved by installing a load resistor across brake-light and earth wires. This "Narva Load Resistor 21W 12V 90034BL" or similar. I think is a common problem, not just with Grenadier.
I also, as above post, put diodes on the two tail-light wires into one tail-light wire for Australian trailers.

Are you able to provide a detailed diagram or some instruction on how/where to install the resistors and what type of diode/where to install these? Any help would be greatly appreciated. Cheers

 

[Mikeb62]

1. Diodes - these are required as the EU 13 pin specification as separate L and R tail light wires, pins 5 and 7. Whereas Australian standard has only one tail light wire. So both EU 13 wires (pin 5 and 7) need diode added in series and then joined together to single trailer wire (pin 7 on 7 pin flat, other AU plugs different pin). The diodes stop current feedback that can generate error messages on IG. I got my auto electrician to install so I don't know what type and size diodes were used. He installed in loom drivers side rear. However, you can install at IG plug as in 21DFDN photos above
2. Load Resistor - This issue occurring depends on trailer lights current draw and is possibly going to vary between trailers. I got advice on this from my specific camper trailer owners forum where an owner of same trailer behind a LR D5 was getting similar problem...but with turn indicators when headlights on. With the IG is seems my trailer stop lights are the problem. I tested a 21W load resistor connected into the pins 6 (stop lights) and pin 3 (earth) at my trailer 7 pin flat connector. Note: the existing wires remain in place the resistor is additional. I have yet to mount resistor permanently but plan to put in area at trailer loom rear drivers side, as it too large to fit in trailer plug and gets quite hot.
My trailer has reverse lights and I didn't need the extra diode 21DFDN refers to.

 

[MattG]

1. Diodes - these are required as the EU 13 pin specification as separate L and R tail light wires, pins 5 and 7. Whereas Australian standard has only one tail light wire. So both EU 13 wires (pin 5 and 7) need diode added in series and then joined together to single trailer wire (pin 7 on 7 pin flat, other AU plugs different pin). The diodes stop current feedback that can generate error messages on IG. I got my auto electrician to install so I don't know what type and size diodes were used. He installed in loom drivers side rear. However, you can install at IG plug as in 21DFDN photos above
2. Load Resistor - This issue occurring depends on trailer lights current draw and is possibly going to vary between trailers. I got advice on this from my specific camper trailer owners forum where an owner of same trailer behind a LR D5 was getting similar problem...but with turn indicators when headlights on. With the IG is seems my trailer stop lights are the problem. I tested a 21W load resistor connected into the pins 6 (stop lights) and pin 3 (earth) at my trailer 7 pin flat connector. Note: the existing wires remain in place the resistor is additional. I have yet to mount resistor permanently but plan to put in area at trailer loom rear drivers side, as it too large to fit in trailer plug and gets quite hot.
My trailer has reverse lights and I didn't need the extra diode 21DFDN refers to.

So did you insert the resistors on the vehicle socket side or the trailer plug side? Still not sure how to go about this. I might have to take the car to an auto electrician to do the work. It seems ridiculously simple, but no one can explain exactly where to attach the resistor leads.

 

[Clark Kent]

So did you insert the resistors on the vehicle socket side or the trailer plug side? Still not sure how to go about this. I might have to take the car to an auto electrician to do the work. It seems ridiculously simple, but no one can explain exactly where to attach the resistor leads.

Take it to your favourite auto elec. Buy once cry once!

Caveat: I've never needed to do this but my non-professional understanding is you do it on the trailer side.
The goal is to increase the current flow in each indicating trailer light circuit by adding additional circuit resistance to increase the current flow to approx 1.75 amps @ 12v: equivalent to the old incandescent bulb rating of 21 watts for indicator and brake bulbs prior to LED.
Because LEDs operate at a lower wattage and current, say 5 watts and 0.4 amps, a vehicle attached to a trailer with LED lights may be unable to determine if the trailer lights are working correctly because it looks for a minimum current flow as a circuit health check, i.e. current flow as expected = lamps must all be working. Low current may mean that one or more lamps has failed (open circuit). High current flow may be a short circuit. Either condition may produce a trailer light error.

The load resistors should be placed in parallel across each circuit/lamp that requires a current increase. The load resistors dissipate heat and are metal cased so should be attached to a metal surface to keep them cool. Don't put them inline in a wiring harness or they can overheat. Google 'Add LED load resistors' for more background but also see this article and diagram for a general guide.
But back to the start: give it to a reputable sparky and sleep easy at night.

 

[Mikeb62]

Mounting to metal surface on the trailer is a good option. On my trailer the wiring is very nicely enclosed, so easier to put in the resistor in the IG. Anywhere, is ok as long as you are connecting into trailer loom. One advantage with trailer mount is sorting issue specific to that trailer, you may have different light circuit causing issue with another trailer.

 

[pedrogb]

But back to the start: give it to a reputable sparky and sleep easy at night.

I did that at the start! But then the smoke! And hence the asking of questions!
I've been back in touch with my auto electrician, and they are having another go next week.
Maybe I'll go to a 7 pin plug, so I can show the photos and say" Just do what they did."
Wish me luck.

 

[Clark Kent]

I did that at the start! But then the smoke! And hence the asking of questions!
I've been back in touch with my auto electrician, and they are having another go next week.
Maybe I'll go to a 7 pin plug, so I can show the photos and say" Just do what they did."
Wish me luck.

That's very unfortunate. If your guy screwed it up then hopefully they'll own their mistakes and sort it out for you.

I fought the temptation to ditch the euro 13 pin. I had my vehicle booked in to a sparky to do a conversion to 12 pin but backed out. I wanted to keep it close to factory but get my camper working (7 pin). I modified only what I needed to in the euro socket to add service brake pin 12. I bought a Narva Euro 13 to Aussie 7 pin adapter and rebuilt it to use 2.5 and 3mm wire, mostly for mechanical strength because it's an unsupported inline adapter. I added a new 2.5mm wire into the adapter from pin 12 (euro) to pin 5 (Aussie) for the service brakes. Sorted.
I do get a trailer error light in reverse. My fix is to drive forwards more than backwards.

Good luck!

 

[pedrogb]

That's very unfortunate. If your guy screwed it up then hopefully they'll own their mistakes and sort it out for you.

I fought the temptation to ditch the euro 13 pin. I had my vehicle booked in to a sparky to do a conversion to 12 pin but backed out. I wanted to keep it close to factory but get my camper working (7 pin). I modified only what I needed to in the euro socket to add service brake pin 12. I bought a Narva Euro 13 to Aussie 7 pin adapter and rebuilt it to use 2.5 and 3mm gauge wire, mostly for mechanical strength because it's an unsupported inline adapter. I added a new 2.5mm wire into the adapter from pin 12 (euro) to pin 5 (Aussie) for the service brakes. Sorted.
I do get a trailer error light in reverse. My fix is to drive forwards more than backwards.

Good luck!

Yep that is my other option, buy a narva 13 pin euro to 7 pin adapter. Should have diodes in it. Then remove 13 pin and fit a 12 pin flat, making my own adapter. But I will let auto leccy hopefully sort it first

 

[MattG]

Just stumbled across this device - White Vision 12v Trailer Trigger Module (WTM500). Apparently wires into the trailer plug or the socket on the vehicle and eliminates error messages and LED lights flickering on trailers. Presumably it works by adding additional resistance to each of the four light circuits (turn signals, brake lights and tail lights). Seems almost too easy to be true, but for only AUD$80, I’m willing to give it a go. Once it arrives, I’ll let you all know whether it works or not! https://whitevision.com.au/product/wtm500-trailer-trigger-module/

 

[pedrogb]

Just come back from a test drive with camper on the back, after a visit to auto leccy.
Everything working as it should, with no warnings, except there is a warning when you reverse, but I guess that's because there are no reverse lights on my camper. Thanks to NQCoolectrix in Townsville.
Very happy with tow performance of the grenadier as well. Camper would be 1500kgs as is. Hardly felt it.

 

[rovie]

Just come back from a test drive with camper on the back, after a visit to auto leccy.
Everything working as it should, with no warnings, except there is a warning when you reverse, but I guess that's because there are no reverse lights on my camper. Thanks to NQCoolectrix in Townsville.
Very happy with tow performance of the grenadier as well. Camper would be 1500kgs as is. Hardly felt it.

Yes, I also have the warnings when I connect my old trailer without reversing lights and old plug. But the lights work perfectly. I therefore ignore this message. I have no problems/warnings with new trailers.

 

[MattG]

Just stumbled across this device - White Vision 12v Trailer Trigger Module (WTM500). Apparently wires into the trailer plug or the socket on the vehicle and eliminates error messages and LED lights flickering on trailers. Presumably it works by adding additional resistance to each of the four light circuits (turn signals, brake lights and tail lights). Seems almost too easy to be true, but for only AUD$80, I’m willing to give it a go. Once it arrives, I’ll let you all know whether it works or not! https://whitevision.com.au/product/wtm500-trailer-trigger-module/

Sadly… This device failed to stop the “Trailer Light Malfunction” warning I get when towing our camper trailer (but only when the headlights are on - Weird I know). Not even 5 Narva 21W Resistors across each lighting circuit in the trailer plug has resolved the issue either. So, as the lights and electric brakes all work exactly as expected, I’ll just ignore the error message and audible alarm that occurs when towing . Hopefully Ineos will come up with a software update/patch that allows the Grenadier to tow trailers with LED lights without throwing up error messages and alarms.

 

[Eric]

Sadly… This device failed to stop the “Trailer Light Malfunction” warning I get when towing our camper trailer (but only when the headlights are on - Weird I know). Not even 5 Narva 21W Resistors across each lighting circuit in the trailer plug has resolved the issue either. So, as the lights and electric brakes all work exactly as expected, I’ll just ignore the error message and audible alarm that occurs when towing . Hopefully Ineos will come up with a software update/patch that allows the Grenadier to tow trailers with LED lights without throwing up error messages and alarms.

I have no issues towing trailers with led or normal lighting PROVIDING the trailer has a reversing lights.
I towed a small trailer without reversing lights and had the error message BUT only when engaging reverse. Now I have the error message on a small trailer as soon as I connect it without engaging drive.
The only thing I haven't done ( because I've just thought of it) is connecting the small trailer with the engine off.

 

[MattG]

I have no issues towing trailers with led or normal lighting PROVIDING the trailer has a reversing lights.
I towed a small trailer without reversing lights and had the error message BUT only when engaging reverse. Now I have the error message on a small trailer as soon as I connect it without engaging drive.
The only thing I haven't done ( because I've just thought of it) is connecting the small trailer with the engine off.

I only have the error message when the headlights turn on (manually or automatic). When wiring the 7 pin flat trailer socket, I connected the left and right tail light wires both into pin 7 on the vehicle socket. I might try installing diodes in-series to both the Left and Right Tail lights within the vehicle wiring loom before reinstalling them both into pin 7 again. As the tail lights do get brighter when the headlights are switched on, this “might” be feeding a tiny bit of reverse current flow. The diodes will stop the reverse current flow and (hopefully) the error message. As the addition of 21W resistors to each lighting circuit (Left turn, right turn, stop lights, reverse and tail lights) did nothing, adding two 45 cent diodes is definitely worth a shot!

 

[pedrogb]

Sorry to hear. I asked my auto electrician what they did, he said he did apply the dark arts, went on to explain the addition of both resistors and diodes. They also said they installed a narva 12 pin flat with a reed switch in it, replacing narva 12pin flat that has been put in place by original owner. Not sure what that does. He said they used the business owner's camper as a test bed. Reverse lights still alarm. Cause I don't have them.