Trailer brake lights will not work - tried 4 other Grenadiers and all the same!

[Tonyh]

Plugged my trailer in and all the lights work except for the brake lights.
Trailer is traditional in terms of all filament lamps and has been towed by a few other makes of car with no issues whatsoever.
My Grenadier throws up a brake light warning, and brake lights on trailer do not work.
Have had 3 other Grenadiers round and they all do exactly the same.
I have tried my mates much older BJ trailer on my Grenadier and the brake lights will not work on that either.
Does anyone else have this problem as Ineos are saying this is not a common problem. In the meantime I cannot tow with the car which makes it useless to me.
I’m not going to start putting resistors etc on the trailer as others tow it and I am 100% confident that we have confirmed that the issue is the Grenadier.
Would welcome any feedback on similar issues and or remedies.
Thanks

 

[pete54]

I get a ‘trailer light error’ when my headlights are on but all the trailer lights work as they should. I had the Grenadier and trailer in at the Stirling Trailer Centre (who conveniently are a Grenadier service centre) and they think it’s something to do with the way the trailer fog light is wired which isn’t recognised by the car. As all appears to work fine I left it at that. Perhaps not very helpful for you but the wiring does seem to be quite sensitive compared to other vehicles. Very frustrating if the break lights aren’t working - sounds like an issue your dealer needs to get to the bottom of.

 

[landmannnn]

Have you got checked the pins on the socket to see if you are getting 12v with the brake lights on?

 

[PC01]

I had the same problem.
Fixed it in the end by having to replace the light fittings on the trailer with CANBUS LED compliant fittings.
The Grenadier just wouldn't work with anything else and threw errors all over the place.
All perfect as soon as I replaced them.

If they are old traditional fittings I think you can get CANBS filament bulbs but mine were LED's

 

[Tonyh]

All pins working as we tried a trailer board on it and it works.
Pin 6 is the brake light feed and it has power coming from it.
Not going to start messing with specific bulbs as I want the car to be able to tow different trailers, bit of an issue especially as no other vehicle has this issue.
I suspect its something to do with the length of wire that goes to the brake lights, a trailer board is only a few feet long so maybe its the resistance it doesn’t like.
Whichever way, Ineos need to fix this and fix it quickly.
Absolutely love the car but if it cannot tow it cannot stay!

 

[landmannnn]

I've got 3 trailers and a bike carrier, a mixture of LEDs and incandescent, no issue with any of them.
One is on a 13 pin plug, the others I use a 7 to 13 adaptor.
Reason for posting - are you using an adaptor? If so, it might be worth testing with another one.

 

[Coullabus]

I've towed a caravan and a couple of different trailers - no issues so far. EXCEPT the frustration that the wiring to run the caravan does not appear to be connected up! My freezer defrosted :-( (covered to death elsewhere in the forum!)

 

[Orcmurd]

Towed a caravan today with my Trialmaster. Brake lights worked fine but I did have a warning light on the dash as one of the caravan number plate lights wasn’t working. Interestingly, when using indicators, an additional indicator tell tale light shows on the dash which appeared to represent the caravan indicators.

For reference the caravan is at least 10 years old and has traditional filament lamps.

 

[Coullabus]

Towed a caravan today with my Trialmaster. Brake lights worked fine but I did have a warning light on the dash as one of the caravan number plate lights wasn’t working. Interestingly, when using indicators, an additional indicator tell tale light shows on the dash which appeared to represent the caravan indicators.

For reference the caravan is at least 10 years old and has traditional filament lamps.

The extra indicator showing the trailer is pretty standard - certainly had it on all the Land Rovers and Volvos I've towed with. Should also show you when the headlights are on.

 

[Tonyh]

I've got 3 trailers and a bike carrier, a mixture of LEDs and incandescent, no issue with any of them.
One is on a 13 pin plug, the others I use a 7 to 13 adaptor.
Reason for posting - are you using an adaptor? If so, it might be worth testing with another one.

My car trailer is 13 pin.
Ineos 13 pin to trailer 13 pin, brake lights don’t work.
Ineos tried a 13 to 7 to 13 pin adapter, brake lights still don't work.
They brought different vehicles to my home each time and tried those, same outcome, brake lights don't work.
I took my car to a mates who has an older 7 pin trailer. 13 pin to 7 pin on my car, brake lights don't work.
I wonder if the CANBUS is not liking trailers?
Whichever way the car needs fixing soon.
Be interesting to see if your car will work on my trailer.
We’re in NW Lancs, you near??

 

[landmannnn]

My car trailer is 13 pin.
Ineos 13 pin to trailer 13 pin, brake lights don’t work.
Ineos tried a 13 to 7 to 13 pin adapter, brake lights still don't work.
They brought different vehicles to my home each time and tried those, same outcome, brake lights don't work.
I took my car to a mates who has an older 7 pin trailer. 13 pin to 7 pin on my car, brake lights don't work.
I wonder if the CANBUS is not liking trailers?
Whichever way the car needs fixing soon.
Be interesting to see if your car will work on my trailer.
We’re in NW Lancs, you near??

It does potentially sound like a fault with your IG. Sorry, I'm in France until October!

 

[Tonyh]

It does potentially sound like a fault with your IG. Sorry, I'm in France until October!

No worries, will have probably got rid of it by then as need a car that’s fit for purpose.

 

[Clark Kent]

My car trailer is 13 pin.
Ineos 13 pin to trailer 13 pin, brake lights don’t work.
Ineos tried a 13 to 7 to 13 pin adapter, brake lights still don't work.
They brought different vehicles to my home each time and tried those, same outcome, brake lights don't work.
I took my car to a mates who has an older 7 pin trailer. 13 pin to 7 pin on my car, brake lights don't work.
I wonder if the CANBUS is not liking trailers?
Whichever way the car needs fixing soon.
Be interesting to see if your car will work on my trailer.
We’re in NW Lancs, you near??

Ineos appear to have mostly followed ISO11446-2 for trailer wiring. Might be worth checking your trailer against the wiring info here. Given the Ineos trailer plug wiring is working for others, and other example vehicles produce the same result with your trailer, it would be worth checking for a wiring inconsistency between your trailer and ISO11446-2. A legacy wiring issue perhaps?

Incandescent bulb trailer lights don't need load resistors. It's the opposite. LED equipped trailers may require load resistors with some CANBUS vehicles because LEDs draw less power.
A typical trailer incandescent 12v brake bulb is 21 watts. An LED equivalent is around 5 watts. Load resistors add a dummy load to make CANBUS sense the normal electrical load for incandescent bulbs. Some vehicles are more or less sensitive to this hence some vehicle and LED trailer combos need load resistors and others don't. It also depends on the numbers of lamps (loads) installed in each lighting circuit.

 

[Rok_Dr]

Thanks @Clark Kent, useful info and I like that it’s the near ultimate source of truth. A trailer wiring section would be worth adding to the next edition of the manual.

Cheers
Steve

 

[Clark Kent]

Thanks @Clark Kent, useful info and I like that it’s the near ultimate source of truth. A trailer wiring section would be worth adding to the next edition of the manual.

Cheers
Steve

That's a great idea Steve. With the different global markets and incomplete implementation of ISO11446-2 it should be straight forward.
Might need some sub-authors in each region to validate the content. Dare I say, a working group?

 

[Rok_Dr]

That's a great idea Steve. With the different global markets and incomplete implementation of ISO11446-2 it should be straight forward.
Might need some sub-authors in each region to validate the content. Dare I say, a working group?

Not sure I'm up to managing working groups LOL but take your point. At present the manual, by necessity, has a strong focus on a MY23 Australian spec vehicle. Maybe in the future when/if I retire fully, but in the meantime feedback and corrections are always appreciated and there will be a few in the next edition.

That said I'm only aware of INEOS cheaping out and deleting pins 10-12 from the vehicle trailer socket.

Cheers
Steve

 

[Clark Kent]

Not sure I'm up to managing working groups LOL but take your point. At present the manual, by necessity, has a strong focus on a MY23 Australian spec vehicle. Maybe in the future when/if I retire fully, but in the meantime feedback and corrections are always appreciated and there will be a few in the next edition.

That said I'm only aware of INEOS cheaping out and deleting pins 10-12 from the vehicle trailer socket.

Cheers
Steve

Just flagging there appears to be some variation between markets, principally the NA market where they get a US spec 7 pin socket in lieu of the 13 pin Euro that other markets get. Depending on what you want to capture in the manual you may need to consider these differences. It would be helpful to document the pin numbers and circuits for the Euro 13 pin and US 7 pin sockets.

 

[Rok_Dr]

Just flagging there appears to be some variation between markets, principally the NA market where they get a US spec 7 pin socket in lieu of the 13 pin Euro that other markets get. Depending on what you want to capture in the manual you may need to consider these differences. It would be helpful to document the pin numbers and circuits for the Euro 13 pin and US 7 pin sockets.

Good point thanks. I wasn't aware the US were blessed with a 7 pin socket. I'll research further. Its a pity Ineos Australia didn't have enough clout to get one for our vehicles. You may get a draft via PM to proof read down the track

 

[Andrew Kilby]

I have exactly the opposite problem. When towing everything is good. I tow a trailer with LEDs and one with Incandescent, no worries with either.

However, when i don't have any trailer connected or the 13 to 7 pin adaptors connected I get a Trailer Light Warning Light on a regular, but not permanent basis. My dealer is blaming the auto electrician who installed the electric brake controller, but it was doing it prior to this being fitted.

The random bings and bongs are doing my head in.

 

[Clark Kent]

I have exactly the opposite problem. When towing everything is good. I tow a trailer with LEDs and one with Incandescent, no worries with either.

However, when i don't have any trailer connected or the 13 to 7 pin adaptors connected I get a Trailer Light Warning Light on a regular, but not permanent basis. My dealer is blaming the auto electrician who installed the electric brake controller, but it was doing it prior to this being fitted.

The random bings and bongs are doing my head in.

I think you're in Sparkie territory there. It sounds like the CANBUS is seeing a random low circuit resistance when there should be high resistance, i.e. open circuit, without a trailer connected. A momentary short between circuits or a small short to ground could produce that result. Trapped water or salt water corrosion in the socket might also do it.