Disco 4 LED Towing Module Problem

[Stevesonbeans]

Hi,

I know there are various related posts on this issue. Hoping to find someone with precise knowledge.

I have installed a Towing Module in my Disco 4 (2010). It is a CARM module. I preferred to install inside the vehicle for a variety of reasons. My Disco has LED lights and so does the trailer.

Bottom line is that it works fine EXCEPT that the indicators do not flash. They are constantly on when I indicate.

Any ideas ?

Steve

[Tombie]

So it doesn't work fine at all.... [emoji6]

How did you wire it in? Where did you tap in etc...

Not enough info..

[Tombie]

Bloody hell... $149 and you had to cut into 5 wiring connections?

Please detail where and how you have wired it in and I scan help..

[Cambo_oldjaguar]

There is a fix for other models, might help you?

Have a look here http://www.aulro.com/afvb/freelander-2/193729-trailer-led-adapter.html

[Stevesonbeans]

Thanks,

I cut into the brake, tail, L flash and R flash wires down the left side of the car that feed the trailer connector. The only slight oddity is that the brake light comes off the high tail light (advised by tow module manufacturer).

Those wires then feed the input side of the tow module. The outputs are then reconnected to the cut wires that feed the trailer connector. The tow module has it's own early and power supply (off the car battery).

I've tried to attach the wiring diagram.

Steve

[Grentarc]

What was the reason for purchasing this unit in the first place? Was it to overcome the D4 not detecting LED trailer lights? If so, this unit would not overcome this problem, as it looks to be designed to REDUCE current draw on the trailer loom.

[Stevesonbeans]

yes to ensure the LED lights on the trailer were detected.

https://www.gore-research.com.au/trailer-towing-adaptor-modules.html

I'm pretty confident this is what they are designed to do.

One thought from the manufacturer is that during the off part of the indicator cycle the voltage doesn't drop far enough for the towing module to register an 'off' signal. Have tested it and the voltage flips between 12V ish (on) and around 0.5V (off). They sent me another towing module having been adjusted that should be filtering out these potential low voltages but it hasn't fixed the problem.

[Stevesonbeans]

by the way, I added the towing module without hooking up the trailer.
When I bought the trailer the manufacturer told me it would have trouble detecting with a Disco 4 so I went ahead with doing the modifications with the Tow Module.

I haven't tried putting it back to where I began to see if works without mods but everything I've read suggests it wont. I also tested on a mates Porsche Cayenne and it didn't work....

Steve

[Grentarc]

They state on their site that it draws an insignificant amount of current so that vehicle ECMs cannot detect it. What it provides is a separation of circuits so that high current trailer lighting bypasses the vehicles wiring (as the box provides power from the battery to the load). The D4 is looking for an extra 1.5 amps on the indicator circuit to detect a trailer, which even if it used PCB mounted relays (over FETs), this unit would not draw enough current.

[Grentarc]

What you need is something like this
http://www.aulro.com/afvb/l319-discovery-3-4/204873-introducing-lance-2.html#post2225314

Chris has put the load resistors in the vehicle and activated by a switch so that with no trailer on, switch off, when hooking up a trailer with LEDs, flick the switch so the load resistors are in the circuit.

[Grentarc]

yes to ensure the LED lights on the trailer were detected.

https://www.gore-research.com.au/trailer-towing-adaptor-modules.html


From their site:
REMEMBER:
All TA200 modules have a high internal input resistance (between 11,900 ohms & 15,200 ohms depending on the exact model). This ensures that no damage will occur when connected to the vehicle's electrics & that the vehicle's ECU will not detect the module. This feature is critical to the sales success of these electronic towbar modules.

If the module was detected by the D4, the way it is wired up, the car would always think a trailer is connected.

[Stevesonbeans]

Ok,

I think I see what you mean.

A lot of older stuff I've read talks about "Tow Assist" and how if the car doesn't know you have a trailer then it wont work. To be honest I'm a bit confused by this, should I assume this is just a built in feature that activates itself ? I've read my manual and it doesn't mention it.

Anyway, I'm still unsure why it doesn't work. If the module is working right it should still be receiving the signal from the indicator and sending on the right signal from the tow module to the connector. It is doing the right thing with the brake light and the indicator on-signal, just not switching off during the flashing.

You're right though, the car will still be none the wiser. Is this a bad move ?
I have a separate new Tow Pro also installed as a brake controller.

Steve

[Tombie]

Too complex when $12 worth of bits would fix it.

Send it back and grab a refund.

Trailer stability is always there, the indicators will work, it just won't optimise the shifts to compensate.

I will even make you a unit that does work if you like....

[Grentarc]

It has been said that the D4 will still activate the trailer stability program when required even if it can't detect it via the lights, as the various sensors in the vehicle will detect the extra load of towing a trailer. Without the lights being detected, the vehicle will still raise to off road height automatically with certain Terrain Response settings (whereas with a detected trailer it won't) and the reverse sensors will not deactivate.

The only thing I can think as to why the box isn't working is that the low voltage between flashes may not be low enough for the box to switch off. Honestly, I would remove the module and wire in some 21w load resistors either permanently inline on the trailer plug loom (so they are only in circuit when a trailer is plugged in - only good if you only ever use LED trailer lights) - or on a switch like Chris has done.

The Tow Pro is a good choice on brake controller - has it been installed like is recommended on this thread? http://www.aulro.com/afvb/l319-discovery-3-4/97935-d4-electric-trailer-brakes.html

[LandyAndy]

Ok,

I think I see what you mean.

A lot of older stuff I've read talks about "Tow Assist" and how if the car doesn't know you have a trailer then it wont work. To be honest I'm a bit confused by this, should I assume this is just a built in feature that activates itself ? I've read my manual and it doesn't mention it.

Anyway, I'm still unsure why it doesn't work. If the module is working right it should still be receiving the signal from the indicator and sending on the right signal from the tow module to the connector. It is doing the right thing with the brake light and the indicator on-signal, just not switching off during the flashing.

You're right though, the car will still be none the wiser. Is this a bad move ?
I have a separate new Tow Pro also installed as a brake controller.

Steve

Steve,
Did you install the Tow Pro???
It MUST be installed as per Sniegys instructions.If not there is a fair chance it wont work,or even worse incorrectly wired brake controlers have been known to apply the brakes when the lights come on.It must not be wired to the brake switch wich is the norm in other vehicles.There is a wire that must be cut to prevent euro style tail lighting activating the brakes and a diode to stop any stray current from a faulty trailer brake feeding into and shorting the ECU,EXPENSIVE!!!!
See this thread.If in doubt ask questions,plenty of us here that have done the job.
Sniegy is a Land Rover dealer mechanic and has wired many vehicles.
Andrew

http://www.aulro.com/afvb/l319-discovery-3-4/97935-d4-electric-trailer-brakes.html

[Tombie]

Close Andy. Shorting the CJB not ECU [emoji6][emoji106]

[LandyAndy]

Close Andy. Shorting the CJB not ECU [emoji6][emoji106]

I will go and sit in the naughty corner for 5 mins:):):):):):)
Andrew

[Stevesonbeans]

I did - or correction, a friend who knows what he is doing did....
I stood by and gave moral support. I'll be sure to pass this on so he can check. I've not tested the brakes yet, have been trying to get the bloody lights to work !
Steve

[Meken]

That module looks like it's made for some other purpose - eg it is a trailer control module - which we already have in the disco. Either take up tombie's offer or look up pulse buster or linear electronic design for ready made (almost plug & play) boxes

[Tombie]

I did - or correction, a friend who knows what he is doing did....
I stood by and gave moral support. I'll be sure to pass this on so he can check. I've not tested the brakes yet, have been trying to get the bloody lights to work !
Steve



Just check - knows what he's doing on D4s or knows what he's doing on old tech like Land Cruisers?

Put it this way - did he remove the LHR tail light at all?
How many wires from rear to front of vehicle did he run?
And did you purchase a Diode at any point? If the answer is no then you likely have a problem..

[Stevesonbeans]

Thanks for all the useful comments.


RE: the TowPro


the installation was done as per Sniegy's guidance with the exception of installing a diode. However I see in the instructions the following


"On the new vehicles there is no 2nd fuse box in the rear nor the need for the Diode."

So I think that means the lack of a diode is OK in my case.




RE: the Tow Module


I'm going to try and just put a couple of resistors in line with the indicators in an attempt to get it working so I can at least get my trailer registered and go camping ! Then figure out the best way to resolve the tow module problem with a bit of time. I'm still not convinced that this module isn't meant to fix all these woes. I appreciate the website refers to "the vehicle's ECU will not detect the module" but my understanding is that it does interact so that the car's systems will know you have a trailer in tow....






Just a question that I posed in part before. I've seen instructional video's online about "Tow Assist" which takes you through a bunch of Q&A to set up a variety of trailer types depending on what you have hooked up. (Involves stickers with dots and putting in dimensions of trailer etc).


I presume my vehicle doesn't have this if it's not in the Instruction Manual. I understand it should do "Towing Stability" automatically (not needing the trailer hitch signal). I presume to stop the reversing signal beep it takes it's cue from having the electrical load (normally).

[Tombie]

Correct. The vehicle pulses the Indicator circuit and if load is detected it will activate the tow based behaviours including shutting off the reverse sensors.

The module is a WOFTAM in a D4 - you have no need to isolate the vehicle from the trailer.
They were more useful in earlier vehicles where the LED lights on the trailer would pulse due to the vehicle checking constantly.

I highly recommend you remove the system, return the vehicle back to standard and return it for credit.

You do not need to do a single other thing to be able to hook up and tow... The remaining resistor set up will help kill the beep when reversing and a slight change to shift points etc. other than that you can tow anytime.

[disco4now]

I'm going to try and just put a couple of resistors in line with the indicators



In Line usually means in series, the resistors need to be in parallel with the indicator LEDs. So one end of each resistor is to earth and the other end is to the lead that drives the LED for each indicator. You need it to draw more current, in series will mean less current.




"On the new vehicles there is no 2nd fuse box in the rear nor the need for the Diode."



This was the original thinking, I had my D4 connected without a diode for 18 months or so, but subsequent advice is to have the diode. You will get away without it, but if something goes wrong with the brake controller you could end up hurting your LandRover, so diode is a recommended precaution.

Your other box thing is not needed on a D4 as it already has separate circuits for towing.

Trust the advice you are getting here.

Regards
Gerry

[Grentarc]

In Line usually means in series, the resistors need to be in parallel with the indicator LEDs. So one end of each resistor is to earth and the other end is to the lead that drives the LED for each indicator. You need it to draw more current, in series will mean less current.


Actually, current flows along the path of least resistance - therefore in a parallel LED and resistor circuit, the resistor is bypassed effectively (LED has much much lower resistance). You need the resistor to be in series to do any good.

Edit -to be totally correct, when you have a parallel circuit, the total circuit resistance is less than the smallest resistor, but total circuit current increases.

If you put a load resistor in series to the trailer plug, the D4 will only register a trailer is connected when a trailer is connected. Put it in parallel on the trailer plug wiring and the D4 will always think a trailer is connected

[Geedublya]

Led has to be parallel to resistor otherwise car won't see trailer.
Led has low resistance and a voltage drop of only 0.6v but has a resistor in series in the light to prevent high current and subsequent failure.

The reason the car doesn't see the led lights is because they draw so little current. You have increase the current draw to the equivalent of a 21W bulb for the car to recognise the trailer.

[Grentarc]

Led has to be parallel to resistor otherwise car won't see trailer.
Led has low resistance and a voltage drop of only 0.6v but has a resistor in series in the light to prevent high current and subsequent failure.

The reason the car doesn't see the led lights is because they draw so little current. You have increase the current draw to the equivalent of a 21W bulb for the car to recognise the trailer.
Sorry,
I just drew the circuit and see where I went wrong - in series the car WILL see the trailer (well, the load resistor), but the voltage drop over the load resistor will mean that the lights probably won't work. You need to have it in parallel (in vehicle it must be switchable) as you want to increase current draw, circuit resistance means nothing to the D4... it's been a long day and a few too many years since I did my DC theory

[Stevesonbeans]

This was the original thinking, I had my D4 connected without a diode for 18 months or so, but subsequent advice is to have the diode. You will get away without it, but if something goes wrong with the brake controller you could end up hurting your LandRover, so diode is a recommended precaution.


Would you mind explaining how it hurts the landrover ? what the path for stray current getting back to the computertronics is ? :p
Thanks,
Steve

[Stevesonbeans]

Also, we've installed a couple of 7ohm resistors in line on the indicators as a interim fix so i can get the thing registered. So I'm happy, but have also found that (the advice here was right) it wont be seen by the D4 so I will still have the reversing beeper screaming at me when trying to reverse.... not ideal.

I suspect I'm heading down the path of "Return" as it's all getting a bit too hard.

[Tombie]

You didn't even have to fit anything to get it registered. Vehicle would still have worked fine...

You're on the right path with returning the item.

[LandyAndy]

This was the original thinking, I had my D4 connected without a diode for 18 months or so, but subsequent advice is to have the diode. You will get away without it, but if something goes wrong with the brake controller you could end up hurting your LandRover, so diode is a recommended precaution.


Would you mind explaining how it hurts the landrover ? what the path for stray current getting back to the computertronics is ? :p
Thanks,
Steve

Its possible to get a 12V feedback from a faulty magnet in the trailer brakes;);););)
The diode will stop it.
Andrew

[LandyAndy]

Also, we've installed a couple of 7ohm resistors in line on the indicators as a interim fix so i can get the thing registered. So I'm happy, but have also found that (the advice here was right) it wont be seen by the D4 so I will still have the reversing beeper screaming at me when trying to reverse.... not ideal.

I suspect I'm heading down the path of "Return" as it's all getting a bit too hard.

You can turn the reverse beeper off/down on the touch screen;););););)
Andrew

[Meken]

Also , The electric brake controller outputs a 12v signal on the red "brake light" wire if you manually operate the controller so you can have 12v feedback to the central junction box & trailer ecu. Not a good situation to have.

[Stevesonbeans]

You can turn the reverse beeper off/down on the touch screen;););););)
Andrew

Not on my model ..... I have the SE.

[Graeme]

Also , The electric brake controller outputs a 12v signal on the red "brake light" wire if you manually operate the controller so you can have 12v feedback to the central junction box & trailer ecu. Not a good situation to have.
It does not harm the MOSFET that does the switching because they are designed to switch solenoids that produce back-EMF (much higher voltage spikes), but no harm fitting a diode if you want to add your own extra protection except that the legal requirement of operating the brake lights won't be satisfied.

[LandyAndy]

Not on my model ..... I have the SE.

Have you got the big screen??? Mine is a base model with the upgraded large screen/reverse cam.If its not on the touchscreen try the volume knob for the duke box.
I had to turn mine down before I bought one of those pulse busta boxes,now thinking it may have been via the volume knob.
Andrew

[Meken]

It does not harm the MOSFET that does the switching because they are designed to switch solenoids that produce back-EMF (much higher voltage spikes), but no harm fitting a diode if you want to add your own extra protection except that the legal requirement of operating the brake lights won't be satisfied.


No if you put the diode in the brake light wire on the cjb side of the junction you still can have the trailer brake lights activated when manually operating - it stops the current back feeding from the junction toward the cjb but the current can still flow from ebc to the trailer lights. And the current from the cjb can still flow to the trailer lights.
Is there an Ecu after the cjb ?

[Peter Best]

Also, we've installed a couple of 7ohm resistors in line on the indicators as a interim fix

Steve,

Did the TA200 manufacturer manage to get your indicators working in the end or did you return it for a credit?

I'm looking to go down a similar path if you got it working without the resistors as I have a large horse trailer that draws heaps of current (has side running lights etc) & the TA200 would be a reasonable solution for me.

[Tombie]

Steve,

Did the TA200 manufacturer manage to get your indicators working in the end or did you return it for a credit?

I'm looking to go down a similar path if you got it working without the resistors as I have a large horse trailer that draws heaps of current (has side running lights etc) & the TA200 would be a reasonable solution for me.



The TA200 is not a solution...Correctly setting up a box and Using the 12N and 12S plugs is...

How many running lights etc are you talking?

[Peter Best]

How many running lights etc are you talking?

The horse float consumes 210W all up with everything running. I also have two large spot lights on the Disco 4 plus running a fridge/freezer, electric brakes etc. The alternator is pretty loaded up so I do not really want to simply add resistors to consume even more power.

I also have a small 6 x 4 trailer with LED lights & I don't want the suspension stiffened when going to the dump etc.

[Grentarc]

The horse float consumes 210W all up with everything running. I also have two large spot lights on the Disco 4 plus running a fridge/freezer, electric brakes etc. The alternator is pretty loaded up so I do not really want to simply add resistors to consume even more power.

I also have a small 6 x 4 trailer with LED lights & I don't want the suspension stiffened when going to the dump etc.
If we are talking watts, the Disco's alternator can handle over 2300w.
In regards to suspension, it can't stiffen the ride without either raising the vehicle, or, you need to have CVDs which the D4 doesn't have.

[Tombie]

No need to worry about the suspension - no such function is triggered as Grentarc mentioned.

The resistors activate the following:
- disable rear parking sensors
- change Transmission shift to optimise towing
- prevents automatic raising of suspension to offroad height (must manually select)

Ok a quick calculation. the float is consuming 15a with everything on - not significant.

The resistors only come into play intermittently- for the fraction of a second the indicator flashes... no risk there.

Your power systems will more than handle what you are asking of them.

My driving lights consume 41amps alone.. [emoji6]

[AndrewM]

The resistors activate the following:
- disable rear parking sensors
- change Transmission shift to optimise towing
- prevents automatic raising of suspension to offroad height (must manually select)


The resistors also activate the flashing trailer on the dash when the indicators are used. If only 1 resistor is installed, all the functions above are activated, except the trailer light only flashes turning one way.

[Peter Best]

The resistors activate the following


Thanks Tombie for this.

So I only need the 2 x indicator resistors to turn off the rear parking sensors?

Is there any reason to install resistors to any of the other light circuits?

Do any of the light circuits on the Disco 4 run pulse width modulation?

How much can I load the existing light circuits before running into "fuse blowing" problems?

[Tombie]

Hi Peter,

Only the indicators (both sides if you want the Dash trailer light to function on both).

Each circuit will handle at least 10a

If you towed it with a normal vehicle the D4 will do it..

If the horse float has an internal light etc you could wire it to the 12S plug and have Aux power...

Let me know what you're looking to do etc and we can easily work it out..

[Grentarc]

Do any of the light circuits on the Disco 4 run pulse width modulation?


The D4 has separate tail light and brake light circuits, so doesn't use PWM to dim the LEDs like other European vehicles (or even my Korean motorcycle!).

[LRD414]

The D4 has separate tail light and brake light circuits, so doesn't use PWM to dim the LEDs like other European vehicles (or even my Korean motorcycle!).

I know that this would be irrelevant to the current trailer socket discussion but I thought the front DRL LEDs used PWM to dim when either the headlights or indicator are on? (The strip LED version since MY14)

Scott

[Grentarc]

I know that this would be irrelevant to the current trailer socket discussion but I thought the front DRL LEDs used PWM to dim when either the headlights or indicator are on? (The strip LED version since MY14)

Scott
Yes, that is true, they do use a PWM at all times, that is why they blink on videos and photos have them in odd states of off/on