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

landmannnn · Aug 11, 2024

If you Google it, there are a number of passthru trailer adaptors that plug into the towing socket that allow led lights to be used, so I don't think that problem is limited to Ineos.

unimogfrog · Aug 11, 2024

My local dealer in CA recently alerted me to a Software Update that has come out in the past few weeks, they said it addresses the Trailer Hitch and the Dashboard display when it's connected.
I haven't had the most recent Update carried out yet, but the Software update that was done several weeks ago allegedly addressed some of the Trailer hitch connections issues as well,
but I was told the NEWEST update resolved some further issues.
So there have been 2 Software updates that I am aware of and I have only done the 1st of the 2 as I don't use the hitch connections too often, but when I checked, my brake lights were working on my Motorcycle carrier.
I too am using a 7-Pin adapter.

The way the Ineos dealers have been working, it might be prudent to inquire to be sure you have the latest Software as a potential fix. I have had several issues with the dealer working on my vehicle that left me bewildered.
I am hoping the open more Authorized service centers ASAP so there are some choices.

Rok_Dr · Aug 12, 2024

I'm going down a trailer wiring rabbit hole writing a new section for the manual.

Can anyone advise:

Is the standard round 7 pin connector fitted to North American spec grenadiers a blade or pin type?
Are brake lights combined with the indicators or separated like the ROW/EU vehicles?

Chers

Steve

anand · Aug 12, 2024

Rok_Dr said:
Can anyone advise:

Is the standard round 7 pin connector fitted to North American spec grenadiers a blade or pin type?

Are brake lights combined with the indicators or separated like the ROW/EU vehicles?

North American trailer wiring combines brake and indicators per side (thus we have LEFT brake/turn and RIGHT brake/turn)

Here is the wiring order for the standard 7 pin connector (truck side)

And what the inside of the truck side connector looks like (again, generic, but this is our standard)

Rok_Dr · Aug 12, 2024

anand said:
North American trailer wiring combines brake and indicators per side (thus we have LEFT brake/turn and RIGHT brake/turn)

Here is the wiring order for the standard 7 pin connector (truck side)
View attachment 7866526

And what the inside of the truck side connector looks like (again, generic, but this is our standard)
View attachment 7866527

Thanks @anand Appreciated. Blade connector it is

Cheers
Steve

Andrew Kilby · Aug 14, 2024

Clark Kent said:
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.

Thanks for the tip. I hope there is some Government Regulation driving this sensor issue. i woudl hate to think that Ineos would do something as complicated as that without being forced.

Clark Kent · Aug 14, 2024

Andrew Kilby said:
Thanks for the tip. I hope there is some Government Regulation driving this sensor issue. i woudl hate to think that Ineos would do something as complicated as that without being forced.

CANBUS is in most if not all modern vehicles. Bosch presented the first version of CANBUS in 1986. It's essentially a simplified data network for complex equipment including motor vehicles.
It has many benefits to the manufacturer and the end user. It makes vehicles cheaper to produce/sell and they weigh less due to simplified wiring. That's good for consumers. CANBUS is a communication service between vehicle components and systems. In respect to lighting circuits CANBUS is also monitoring for the malfunction or failure of a lamp or bulb, including trailer lights where equipped. That's a good thing.
The system is sensitive to changes in electrical resistance. Unfortunately that can also result from equipment degradation. Get your vehicle checked. It may not be a complex fault.

Tonyh · Aug 14, 2024

I’m getting the impression that Ineos think its my trailer, despite any other car that connects to it does not have a problem, unlike every IG connected all have the same problem.
It should not be up to me to have my trailer wiring checked as its a relatively modern unit and was certainly not a cheap budget model.
I have asked for a refund as sick of the issue the car has, looks like Ineos will drag their feet on this one.
Why do all other cars work when connected and all Grenadiers do not?
Maybe a Master Auto Electrician could diagnose but don’t see why I should have to initiate this - all I want is for my expensive optional tow bar and electrics that I paid for to do its damn job properly!

Steve.B · Aug 15, 2024

Clark Kent said:
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.

Well Clark Kent,

It seems you can lead a horse to water, but you can not make it drink.
If I had a problem with my caravan wiring, I would be doing as you articulate above.

Clark Kent · Aug 15, 2024

Steve.B said:
Well Clark Kent,

It seems you can lead a horse to water, but you can not make it drink.
If I had a problem with my caravan wiring, I would be doing as you articulate above.

I did my best to help

.
I feel @Tonyh 's frustration. This should just work but there are a lot of variables that need to line up with different generations of tech in service so it's unsurprising that some equipment is not plug and play.

I think Tony was close to identifying the issue back at post #5: '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.'
That sounds like a trailer issue?

Hi @Tonyh. Sorry this hasn't worked out for you. Good luck with the refund process.

Tonyh · Aug 15, 2024

Clark Kent said:
I did my best to help .
I feel @Tonyh 's frustration. This should just work but there are a lot of variables that need to line up with different generations of tech in service so it's unsurprising that some equipment is not plug and play.

I think Tony was close to identifying the issue back at post #5: '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.'
That sounds like a trailer issue?

Hi @Tonyh. Sorry this hasn't worked out for you. Good luck with the refund process.

I suspect Ineos have the same ‘sounds like a trailer issue’ as you state.
It is NOT a trailer issue that can be blamed for the problem, especially as NO other cars/vans/SUV’s have a problem when connected. This is the frustrating point that Ineos don’t seem to be able to grasp.
Don’t get me wrong, I really like the car and want to keep it, its just that I dont think it unreasonable that Ineos pull their fingers out and fix this issue urgently. I think that if I had gone for a retrospective tow bar fitting, this problem would not be seen as I understand that there would be no fancy circuitry that turns the parking sensors and disables stop/start when connected.
They need to sort this, especially as 3 other IG from Dealership all have exactly the same issue which cannot be coincidental.

landmannnn · Aug 15, 2024

Just go and buy one of these

PC01 · Aug 15, 2024

Tonyh said:
I suspect Ineos have the same ‘sounds like a trailer issue’ as you state.
It is NOT a trailer issue that can be blamed for the problem, especially as NO other cars/vans/SUV’s have a problem when connected. This is the frustrating point that Ineos don’t seem to be able to grasp.
Don’t get me wrong, I really like the car and want to keep it, its just that I dont think it unreasonable that Ineos pull their fingers out and fix this issue urgently. I think that if I had gone for a retrospective tow bar fitting, this problem would not be seen as I understand that there would be no fancy circuitry that turns the parking sensors and disables stop/start when connected.
They need to sort this, especially as 3 other IG from Dealership all have exactly the same issue which cannot be coincidental.

Hi Tonyh
I did reply in earlier thread and sympathise with your frustrations.
I had the same frustrations having had an auto electrician crawl all over the trailer trying to fix the issue.
I would confirm I have a number of other "new" and "older" cars, each of which didn't throw up the same issues as the Grenadier when connected to my trailer.
We tried fitting resisters of differing weights (all of which got too hot in my opinion and didn't solve anyway), cut in and fitted a universal bypass relay, etc, etc - none solved the issue.
The issue however went away as soon as I substituted my trailer LED lights with the CANBUS approved lights.
The ones I fitted were as below - Fristom FT-370 Rear Trailer Light with LED Control System
They were about £40 (exc VAT) each if I remember correctly, and would have saved a a lot of time and money if I had gone this route to start with.
Hope this helps

Tonyh · Aug 15, 2024

PC01 said:
Hi Tonyh
I did reply in earlier thread and sympathise with your frustrations.
I had the same frustrations having had an auto electrician crawl all over the trailer trying to fix the issue.
I would confirm I have a number of other "new" and "older" cars, each of which didn't throw up the same issues as the Grenadier when connected to my trailer.
We tried fitting resisters of differing weights (all of which got too hot in my opinion and didn't solve anyway), cut in and fitted a universal bypass relay, etc, etc - none solved the issue.
The issue however went away as soon as I substituted my trailer LED lights with the CANBUS approved lights.
The ones I fitted were as below - Fristom FT-370 Rear Trailer Light with LED Control System
They were about £40 (exc VAT) each if I remember correctly, and would have saved a a lot of time and money if I had gone this route to start with.
Hope this helps

View attachment 7866877

Thanks for advice but I cannot change the rear lights on my trailer. This is a very expensive fully enclosed car transporter trailer and therefore has bespoke rear light arrangements. All the other lights work, its literally just the brake lights.
Lets see what Ineos come up with, hopefully they will provide a suitable solution?

Tonyh · Aug 15, 2024

landmannnn said:
Just go and buy one of these

View attachment 7866851

I assume this what you had to do to Solve this problem?

G-Man · Aug 15, 2024

landmannnn said:
Just go and buy one of these

Nice one, I didn't know these existed! I've had trailer light warnings on my dashboard even though the actual lights on the trailer seem to be working fine. Perhaps this'll fix it.

I've tracked the website down selling the adapter here

landmannnn · Aug 15, 2024

Tonyh said:
I assume this what you had to do to Solve this problem?

Not personally.

landmannnn · Aug 15, 2024

G-Man said:
Nice one, I didn't know these existed! I've had trailer light warnings on my dashboard even though the actual lights on the trailer seem to be working fine. Perhaps this'll fix it.

I've tracked the website down selling the adapter here

There's a few different variations, none of them cheap though!

Tonyh · Aug 22, 2024

Update.
I have 4 brake lights on my trailer. Removed a bulb from one at each side and no warning lights came on!!
Replaced with LED and again no warning lights. Have now replaced all 4 filament brake light bulbs with LED and no warning lights are showing - result.
Looks like it’s a CANBUS issue as whilst I can now tow my trailer, I still cannot tow any other one.
Interestingly small trailers seem ok, its the larger ones like car transporter trailers that produce the error warnings.
My local Dealership brought an MOT tester and my car failed. Was told that it looks like Ineos may have a problem here as ALL the other Ineos’s that they have been plugged in have all failed!
If no fix is found it looks like my car will probably have a 3 year shelf life - no MOT means not roadworthy.
May be an idea for everyone to get the MOT test plugged in to the tow socket.

G-Man · Aug 23, 2024

Tonyh said:
Update.
I have 4 brake lights on my trailer. Removed a bulb from one at each side and no warning lights came on!!
Replaced with LED and again no warning lights. Have now replaced all 4 filament brake light bulbs with LED and no warning lights are showing - result.
Looks like it’s a CANBUS issue as whilst I can now tow my trailer, I still cannot tow any other one.
Interestingly small trailers seem ok, its the larger ones like car transporter trailers that produce the error warnings.
My local Dealership brought an MOT tester and my car failed. Was told that it looks like Ineos may have a problem here as ALL the other Ineos’s that they have been plugged in have all failed!
If no fix is found it looks like my car will probably have a 3 year shelf life - no MOT means not roadworthy.
May be an idea for everyone to get the MOT test plugged in to the tow socket.

Sounds like Ineos have roughly 2 years to fix it before they have an embarrassing situation on their hands in that case, at least in the UK. Is it safe to assume your dealer reported the finding back to Ineos?

What exactly would not be up to the MOT pass mark? The available power on the trailer circuit? Seems a bit obscure given that it works fine for LED light boards. I suspect most MOT test centres wouldn't bother checking it, unless it became common knowledge and they wanted some sport

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

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