Floyd
Well-Known Member
Please go back and read my comment @ #179
It actually obviates that portion of my comment which you quoted and which I had already deleted as you responded!
Thanks again!
Sponsored
Last edited:
Sponsored
Ford warns that Active Cruise Control can NOT be used with an aftermarket trailer brake controller
It actually obviates that portion of my comment which you quoted and which I had already deleted as you responded!
Thanks again!
TechnicallyReal
Well-Known Member
Gotcha ?Please go back and read my comment @ #179
It actually obviates that portion of my comment which you quoted and which I had already deleted as you responded!
Thanks again!
I guess I hadn't considered that the way ACC works might not be well known. Not only does ACC cap your speed to that of the vehicle in front of you, and not only will it let off the gas when that vehicle slows down, it can also automatically apply the brakes to maintain a safe distance.
Honestly it works really well to make an annoying drive in heavy traffic, less annoying. But when people merge in front of you, ACC freaks out and hits the brakes pretty hard. Usually harder than needed.
TheMonk
New Member
Just catching up to this thread now as I've started looking into Trailer Brake controllers in 2025 for my 2020 ranger.
Seems like the debate about adaptive braking has been decided for us. The OEM part appears to be discontinued and while I can buy the redarc trailer brake controller no problem it also appears the Lumen module is no longer available anywhere. From what I can gather it's just not produced anymore.
So much for any AEB or ACC braking applications.
Thread I started earlier today on the topic:
https://www.ranger5g.com/forum/threads/redarc-parts-for-trailer-brake-controller.37625/#post-805707
Seems like the debate about adaptive braking has been decided for us. The OEM part appears to be discontinued and while I can buy the redarc trailer brake controller no problem it also appears the Lumen module is no longer available anywhere. From what I can gather it's just not produced anymore.
So much for any AEB or ACC braking applications.
Thread I started earlier today on the topic:
https://www.ranger5g.com/forum/threads/redarc-parts-for-trailer-brake-controller.37625/#post-805707
t4thfavor
Well-Known Member
Probably have tens of thousands of towing miles on my Ranger and all I’ve ever used ( picked up new in Feb of 2019) was a teknosha p3 or whatever ( I can’t even remember). I wouldn’t use adaptive cruise or even cruise at all if I was pulling a trailer that needed the brakes. The p3 is sensitive enough to work properly under almost all braking conditions and I even think it comes on slightly if the truck downshifts while going down a grade. It’s got a gyro in it so it knows if the vehicle is accel or decel. There wasn’t a ford approved module when I got my truck and then once there was, I wasn’t about to pull apart 3/4 of the trim inside the truck just to splice into a brake signal for the lamp. In my opinion ford should have been installing that module for free as a safety recall on all trucks equipped with the factory hitch but here we are…
airline tech
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I really wish that Ford would provide more detail on this, mainly the reason for requiring the Lumen ECU to get the (Brake Light-Active) signal.
It is not in any of the service manuals and we are relying on theories on how it truly operates.
I can confirm that without physically pushing the Brake Pedal the TBC does not know the brakes are applied.
I can confirm that the (ABS) module sends a data message to the BCM:
Emergency Brake Lamp Request to turn on the - Stop/Brake Lights.
And that information comes from the Can-Bus data transmission information pages, it is not mentioned anywhere else.
It makes sense, you want the drives behind you to know that the brakes are being applied.
with that - I cannot confirm that the Brake Lights (Flash) during the (AEB or ACC Deceleration)
So they tap off the CHMSL light as it will see (Normal / AEB / ACC) inputs, now this voltage (if it flashes) in a auto braking event will cause the (TBC) not to receive a true brakes applied signal.
Thus if this is true is the reason for the additional Lumen Module and it ignores the pulsing voltage. I cannot find a verified document on how the brake lights operate in a Auto-Brake event.
This would be some helpful information to fully determine if the Lumen Module is actually needed.
Even if the Brake Lights do not (flash) pulse you are still dealing with tapping into a lighting circuit and the TBC will need to draw power from and tapping into the CHML would have some voltage drop at that connection and it is known that the Ranger does not like or deal with adding options to the lighting circuits due to the (FET) circuit protection.
I find it frustrating that Ford discontinued the kit, now I do not normally tow and have no plans on ever towing anything that would require the extra TBC, but I do question:
Can you tap into the (CHMSL) or any brake light source and it function the same as if you had the Lumen Module without errors.
Yes it has been mentioned on here that the Lumen Module (conditions) the signal and this may be referencing the flashing brake lights but since there is not a detailed description on what the module actually does (Detailed Info) its hard to give a true answer - Is the Lumen Module actually needed?
Yes you can turn off (Active Braking) but keep in mind that when you cycle the ignition it resets back to active and (ACC) stays off unless you physically enable it.
From a operational stand-point the standard TBC will work normally and the only issue would arise in a (AEB) event and how much pressure is actually being applied to the brakes and when the event happens (Straight Road - Curve - Downhill) as well as the amount of time the (AEB) is in control and you physically get on the brake pedal.
If you are awake and alert not looking down at the dash (startled by the alert) as what the heck is that it will be seconds - its a natural motion to look down when that alert activates.
I have not had the (AEB) trigger but have had the (Alert) a few times for deer on the side of the road. It does grab your attention as the alert sometimes will trigger before I actually see the shadow of the head.
It would be great to see a detailed operation note of that Lumen ECU to make the determination of is it really needed or can we just tap the brake light source without it and also get a verified operation of the Brake Lights in (AEB and ACC) brake application if they actually flash then I can see it being needed - if they don't then it may just work
It is not in any of the service manuals and we are relying on theories on how it truly operates.
I can confirm that without physically pushing the Brake Pedal the TBC does not know the brakes are applied.
I can confirm that the (ABS) module sends a data message to the BCM:
Emergency Brake Lamp Request to turn on the - Stop/Brake Lights.
And that information comes from the Can-Bus data transmission information pages, it is not mentioned anywhere else.
It makes sense, you want the drives behind you to know that the brakes are being applied.
with that - I cannot confirm that the Brake Lights (Flash) during the (AEB or ACC Deceleration)
So they tap off the CHMSL light as it will see (Normal / AEB / ACC) inputs, now this voltage (if it flashes) in a auto braking event will cause the (TBC) not to receive a true brakes applied signal.
Thus if this is true is the reason for the additional Lumen Module and it ignores the pulsing voltage. I cannot find a verified document on how the brake lights operate in a Auto-Brake event.
This would be some helpful information to fully determine if the Lumen Module is actually needed.
Even if the Brake Lights do not (flash) pulse you are still dealing with tapping into a lighting circuit and the TBC will need to draw power from and tapping into the CHML would have some voltage drop at that connection and it is known that the Ranger does not like or deal with adding options to the lighting circuits due to the (FET) circuit protection.
I find it frustrating that Ford discontinued the kit, now I do not normally tow and have no plans on ever towing anything that would require the extra TBC, but I do question:
Can you tap into the (CHMSL) or any brake light source and it function the same as if you had the Lumen Module without errors.
Yes it has been mentioned on here that the Lumen Module (conditions) the signal and this may be referencing the flashing brake lights but since there is not a detailed description on what the module actually does (Detailed Info) its hard to give a true answer - Is the Lumen Module actually needed?
Yes you can turn off (Active Braking) but keep in mind that when you cycle the ignition it resets back to active and (ACC) stays off unless you physically enable it.
From a operational stand-point the standard TBC will work normally and the only issue would arise in a (AEB) event and how much pressure is actually being applied to the brakes and when the event happens (Straight Road - Curve - Downhill) as well as the amount of time the (AEB) is in control and you physically get on the brake pedal.
If you are awake and alert not looking down at the dash (startled by the alert) as what the heck is that it will be seconds - its a natural motion to look down when that alert activates.
I have not had the (AEB) trigger but have had the (Alert) a few times for deer on the side of the road. It does grab your attention as the alert sometimes will trigger before I actually see the shadow of the head.
It would be great to see a detailed operation note of that Lumen ECU to make the determination of is it really needed or can we just tap the brake light source without it and also get a verified operation of the Brake Lights in (AEB and ACC) brake application if they actually flash then I can see it being needed - if they don't then it may just work
t4thfavor
Well-Known Member
The module changed the pwm signal from the brake lamp circuit to a steady digital on/off signal that the brake controller understands. The tbc is a progressive controller with an accelerometer so it can “figure out” how much brake is being applied and do the same with the trailer brakes. Once the driver is actually on the brakes it just behaves like a regular controller. This info was provided on one of the forum posts by either red arc or someone from ford right around the time when the announcement came that we needed the module and the expensive controller that you needed to rip apart your interior and drill holes in it.
VAMike
Well-Known Member
IMO it comes down to whether you'd ever have an AEB event and not also hit the brakes. But nobody in a position to know whether that's true will confirm that. I can't imagine that situation coming up so it's not something I'd worry about.
What I'd worry more about is what happens with one of the 7-pin mounted controllers if there's an AEB activation (do the lights still pulse even if you hit the brakes, and do the trailer brake lights--and the trailer brakes--also pulse?) Again, I don't expect we'll ever get an answer to that.
What I'd worry more about is what happens with one of the 7-pin mounted controllers if there's an AEB activation (do the lights still pulse even if you hit the brakes, and do the trailer brake lights--and the trailer brakes--also pulse?) Again, I don't expect we'll ever get an answer to that.
t4thfavor
Well-Known Member
If the 7pin also pulsed then there would be no need to cut into the center brake light to secure the brake signal as it would be present at the harness under the dash.
VAMike
Well-Known Member
I don't know for sure one way or the other, but brake activation via pedal signal and trailer brake light signal are two different things so there's no fundamental reason they'd be the same.
t4thfavor
Well-Known Member
I’m just stating that if the aeb or acc brake signal made it to the trailer you could capture that signal with the lumen module and not have to get it from the center brake light. So “no” it doesn’t pulse the brakes at the 7-pin and “no” it doesn’t pulse the lamp output at the 7-pin on either aeb or acc brake events.
VAMike
Well-Known Member
I don't understand why you're asserting that--"brake light" isn't one of the four dangley wires under the dash (which is the entire problem). But "brake light" is one of the wires that's present in the 7 pin socket which is how the 7pin brake controllers work. Ford almost certainly could have tapped the "brake light" signal somewhere under the dash, but they have a rule that says you can't tap a wire, and they wouldn't would want to pull apart one of the main wiring harnesses to insert a tap module (the way they did for the center brake light) for something like this because if a mechanic screws that up it's a much bigger problem than just screwing up the center brake light.
t4thfavor
Well-Known Member
Incorrect sir, regular brake light signal is present under the dash, in the 7-pin, and in the brake controller harness. Emergency and acc brake signal is only present deep in the harness or up in the headliner. There is actually a procedure somewhere on this forum for how to install the lumen module by tapping the harness instead.
VAMike
Well-Known Member
That's literally what I said--the brake light signal is there, but not in a form that's usable per ford's guidelines. There are four exposed wires which provide 12V, ground, pedal activation signal, and brake power to the 7 pin (not brake light, which is left & right turn signal lights together). Are you maybe confusing brake light and brake power? Otherwise I really don't get what you're arguing.
airline tech
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I will try to shed some light on this subject, granted the manuals do not cover a full description of operation of (AEB or ACC Decel - Braking)
TBC (Only Installed)
TBC Wiring
So above we have Power (VBAT) and Ground to the TBC
Then the TBC (Out) to the Trailer Adapter - This is the Trailer Brake Control (Apply) signal
To get that signal the Brake Pedal must be applied to close the switch.
This is all the TBC can do by itself.
Note the missing input (Brake Lights) Applied the Brake Lights come from HS1-Can Bus Data
Power Feed to the BPP
This is a deeper look into the power feed:
Fuse 47 feeds power to the BPP and when the switch closes it sends power to 2 circuits for a signal.
The BCM (BPP) Brake Pedal Position and the PCM (BPP & BPS).
If we focus on the BCM input, the power is tapped off of that 10A fused power and feeds another fuse (Fuse 4) which feeds the input into the TBC and when the micro controller sees a power input on pin #1 it generates a data transmission on HS1-Can to activate the brake lights.
Note: This is Unregulated Voltage - so full battery voltage feeding the TBC
This is where the issue lies, the TBC does not see the Brake Lights Applied (output) and the reason for the Lumen Module as it was designed to pick up that data transmission when the lights trigger on.
I dug into the As-Built Files as well as the Data Transmission Message charts to see if I could find anything that showed if - During a (Automated Braking) event do the brake lights pulse?
I do not see anything stating or showing that.
I would expect I would find a (As-Built) setting to configure it - I do not see it.
But did find this setting in the As-Builts
BCM- 726-26-01 xxxx-xxx3-xxxx - We are set to 3 - Control Stop & Position Configure
3=VRMS/VRMS
Options are: 0= Duty/Duty - 1= Duty/VRMS - 2=VRMS/Duty
So the BCM is using this to stabilize and regulate the voltage on the Brake Light Circuit.
I do not have a clear answer as to why this input cannot be used for the TBC (Brake On) signal as a input - I have a hunch it would be (Under voltage) and not enough for the TBC to pick it up (efficiently) as its looking for a varying voltage input vs constant and stable so they brought in Lumen to assist with that input.
Again, I cannot see the inner workings of the Lumen Module
And here are the related Data Messages that are sent over the Can Busses.
Noted as (Originating Module) - (Data Bus Used) - (Receiving Module or Modules)
Note: GWM = Gateway Module and it allows the data busses to cross communicate
Brake On/Off Switch:
PCM - (HS1-Can)-GWM / GWM-(HS3-Can)-APIM
Brake Pedal Applied:
PCM-(HS4-Can)-GWM / GWM - (HS2-Can) - ABS-IPMA-RCM-OSCM
GWM - (HS3-Can) - APIM-IPC-ACM
Note: The RCM (Restraint Control Module) contains all the Accelerometers etc.
Collision Mitigation by Braking (Engine Torque):
PCM - (HS1-Can) - GWM / GWM - (HS2-Can) - IPMA
Emergency Brake Lamp Request:
ABS- (HS2-Can) - GWM / GWM - (HS1-Can) - BCM
Note: This is a output of the ABS module, this message is sent if the Collision Avoidance has actively applied the brakes (Immanent collision)
Stop Lamp Brake Request:
ABS - (HS2-Can) - GWM / GWM - (HS1-Can) - BCM
Note: This is a output of the ABS module, this message is sent if the ACC wants to apply the brakes to slow the vehicle down. (Auto-Control - of the Active Cruise Control System)
Stop Lamp Request:
BCM- (HS1-Can) - GWM / GWM - (MS-Can) - TRM
NOTE: This is from the input of the Brake Pedal Position Switch (BPP) which powers the Brake Light circuit. Note the BCM is the originating module.
NOTE 2: the TRM feeds power out to the Trailer Connector, so if you tap the input at the trailer connector its a secondary source.
Note: Being that this is the only message that specifically states that the message is being sent to the TRM, I think that any and all HS1-Can (Brake Light) apply messages will also trigger the trailer lights on no matter what module initiates it even though they do not list it as a receiving module.
Trailer Lamp Connected:
TRM - (MS-Can) - SODL/SODR - GWM / GWM - (HS1-Can) - PAM - PCM - BCM
GWM - (HS2-Can) - ABS -IPMA / GWM - (HS3-Can) - APIM- IPC
So in short the Brake Lights are controlled (Triggered to Power) via the HS1-Can Bus by the BCM and at the GWM that data transmission is shared by the MS-Can bus feeding into the TRM
The reason for the Lumen Module is it needs to be able to (read) the HS1-Can data to see that the brake lights are applied or requested or the secondary data message from MS-Can.
Since the Lumen Module uses the CHMSL as its input source - the CHMSL is commanded on by the HS1-Can bus signal that is powered from the BCM as you will note any Brake/Stop Lamp request is sent along the HS1-Can bus.
Where to Tap - Debate
The Lumen Module taps the CHMSL for convenience, easy and cheap to make a simple T-Harness, a short wire run that is routed inside the cab and the light illumination is driven by HS1-Can bus.
Alternative Options: (HS1-Can) controlled
Wire Tap BCM Connector: C2280D (Pin #13) this is the output feed to the CHMSL, this is the only thing on this circuit.
This is the same as running a wire feed above the headliner, but you are tapping a main harness.
Wire Tap BCM Connector C2280F (Pin # 12) this is the output feed to the Rear Taillamp (Stop-Light) circuit - this feeds both sides
Wire Tap: Either side Rear Taillamp (Brake-Light) input, but this requires external wire routing and getting that input into the cab.
TRM - Output (MS-CAN) options
As the HS1-Can data is sent to the TRM, the TRM translates the HS1-Can data and activates the Brake Light output power to the trailer connector.
This is secondary data transmission and to get an input that the brake lights are requested on requires it to go through the TRM to get it.
Now we know that the Lumen Module will accept the input that the BCM outputs but will it accept the output signal of the TRM (?)
2 separate modules providing the power source for brake lights depending on where you tap for it and since we do not have the (Lumen) requirement specs for that input voltage it would be best to stay with the BCM output source, In my opinion.
Does it matter ? - IDK - Probably Not
But here are some options:
Wire Tap either Brake Light (output) at the TRM itself, keeps it inside the cab - short wire run
C2498C
Pin #1 = Left Brake Light
Pin #8 = Right Brake Light
Wire Tap either Brake Light (Output) feed at the Truck Side (Trailer Connector)
Edit:
Thanks to @BigBlue - highlighting my error in overlooking (forgetting) that important detail as I have been through this circuit in the past and vaguely remember the TRM does (intermix) the 2 light circuits (noted below)
I am now editing my above and due to the fact that the circuit from the TRM (Back) to the Trailer Connector would be powered by both Brake & Turn so the turn signal in addition to the brake lights would be a input to the Lumen Module, it would know know the difference.
So this rules out the TRM and Trailer Connector as a tap point
From my previous venture into the circuit as ref
TBC (Only Installed)
TBC Wiring
So above we have Power (VBAT) and Ground to the TBC
Then the TBC (Out) to the Trailer Adapter - This is the Trailer Brake Control (Apply) signal
To get that signal the Brake Pedal must be applied to close the switch.
This is all the TBC can do by itself.
Note the missing input (Brake Lights) Applied the Brake Lights come from HS1-Can Bus Data
Power Feed to the BPP
This is a deeper look into the power feed:
Fuse 47 feeds power to the BPP and when the switch closes it sends power to 2 circuits for a signal.
The BCM (BPP) Brake Pedal Position and the PCM (BPP & BPS).
If we focus on the BCM input, the power is tapped off of that 10A fused power and feeds another fuse (Fuse 4) which feeds the input into the TBC and when the micro controller sees a power input on pin #1 it generates a data transmission on HS1-Can to activate the brake lights.
Note: This is Unregulated Voltage - so full battery voltage feeding the TBC
This is where the issue lies, the TBC does not see the Brake Lights Applied (output) and the reason for the Lumen Module as it was designed to pick up that data transmission when the lights trigger on.
I dug into the As-Built Files as well as the Data Transmission Message charts to see if I could find anything that showed if - During a (Automated Braking) event do the brake lights pulse?
I do not see anything stating or showing that.
I would expect I would find a (As-Built) setting to configure it - I do not see it.
But did find this setting in the As-Builts
BCM- 726-26-01 xxxx-xxx3-xxxx - We are set to 3 - Control Stop & Position Configure
3=VRMS/VRMS
Options are: 0= Duty/Duty - 1= Duty/VRMS - 2=VRMS/Duty
So the BCM is using this to stabilize and regulate the voltage on the Brake Light Circuit.
I do not have a clear answer as to why this input cannot be used for the TBC (Brake On) signal as a input - I have a hunch it would be (Under voltage) and not enough for the TBC to pick it up (efficiently) as its looking for a varying voltage input vs constant and stable so they brought in Lumen to assist with that input.
Again, I cannot see the inner workings of the Lumen Module
And here are the related Data Messages that are sent over the Can Busses.
Noted as (Originating Module) - (Data Bus Used) - (Receiving Module or Modules)
Note: GWM = Gateway Module and it allows the data busses to cross communicate
Brake On/Off Switch:
PCM - (HS1-Can)-GWM / GWM-(HS3-Can)-APIM
Brake Pedal Applied:
PCM-(HS4-Can)-GWM / GWM - (HS2-Can) - ABS-IPMA-RCM-OSCM
GWM - (HS3-Can) - APIM-IPC-ACM
Note: The RCM (Restraint Control Module) contains all the Accelerometers etc.
Collision Mitigation by Braking (Engine Torque):
PCM - (HS1-Can) - GWM / GWM - (HS2-Can) - IPMA
Emergency Brake Lamp Request:
ABS- (HS2-Can) - GWM / GWM - (HS1-Can) - BCM
Note: This is a output of the ABS module, this message is sent if the Collision Avoidance has actively applied the brakes (Immanent collision)
Stop Lamp Brake Request:
ABS - (HS2-Can) - GWM / GWM - (HS1-Can) - BCM
Note: This is a output of the ABS module, this message is sent if the ACC wants to apply the brakes to slow the vehicle down. (Auto-Control - of the Active Cruise Control System)
Stop Lamp Request:
BCM- (HS1-Can) - GWM / GWM - (MS-Can) - TRM
NOTE: This is from the input of the Brake Pedal Position Switch (BPP) which powers the Brake Light circuit. Note the BCM is the originating module.
NOTE 2: the TRM feeds power out to the Trailer Connector, so if you tap the input at the trailer connector its a secondary source.
Note: Being that this is the only message that specifically states that the message is being sent to the TRM, I think that any and all HS1-Can (Brake Light) apply messages will also trigger the trailer lights on no matter what module initiates it even though they do not list it as a receiving module.
Trailer Lamp Connected:
TRM - (MS-Can) - SODL/SODR - GWM / GWM - (HS1-Can) - PAM - PCM - BCM
GWM - (HS2-Can) - ABS -IPMA / GWM - (HS3-Can) - APIM- IPC
So in short the Brake Lights are controlled (Triggered to Power) via the HS1-Can Bus by the BCM and at the GWM that data transmission is shared by the MS-Can bus feeding into the TRM
The reason for the Lumen Module is it needs to be able to (read) the HS1-Can data to see that the brake lights are applied or requested or the secondary data message from MS-Can.
Since the Lumen Module uses the CHMSL as its input source - the CHMSL is commanded on by the HS1-Can bus signal that is powered from the BCM as you will note any Brake/Stop Lamp request is sent along the HS1-Can bus.
Where to Tap - Debate
The Lumen Module taps the CHMSL for convenience, easy and cheap to make a simple T-Harness, a short wire run that is routed inside the cab and the light illumination is driven by HS1-Can bus.
Alternative Options: (HS1-Can) controlled
Wire Tap BCM Connector: C2280D (Pin #13) this is the output feed to the CHMSL, this is the only thing on this circuit.
This is the same as running a wire feed above the headliner, but you are tapping a main harness.
Wire Tap BCM Connector C2280F (Pin # 12) this is the output feed to the Rear Taillamp (Stop-Light) circuit - this feeds both sides
Wire Tap: Either side Rear Taillamp (Brake-Light) input, but this requires external wire routing and getting that input into the cab.
As the HS1-Can data is sent to the TRM, the TRM translates the HS1-Can data and activates the Brake Light output power to the trailer connector.
This is secondary data transmission and to get an input that the brake lights are requested on requires it to go through the TRM to get it.
Now we know that the Lumen Module will accept the input that the BCM outputs but will it accept the output signal of the TRM (?)
2 separate modules providing the power source for brake lights depending on where you tap for it and since we do not have the (Lumen) requirement specs for that input voltage it would be best to stay with the BCM output source, In my opinion.
Does it matter ? - IDK - Probably Not
But here are some options:
Wire Tap either Brake Light (output) at the TRM itself, keeps it inside the cab - short wire run
C2498C
Pin #1 = Left Brake Light
Pin #8 = Right Brake Light
Wire Tap either Brake Light (Output) feed at the Truck Side (Trailer Connector)
Edit:
Thanks to @BigBlue - highlighting my error in overlooking (forgetting) that important detail as I have been through this circuit in the past and vaguely remember the TRM does (intermix) the 2 light circuits (noted below)
I am now editing my above and due to the fact that the circuit from the TRM (Back) to the Trailer Connector would be powered by both Brake & Turn so the turn signal in addition to the brake lights would be a input to the Lumen Module, it would know know the difference.
So this rules out the TRM and Trailer Connector as a tap point
From my previous venture into the circuit as ref
Last edited:
Big Blue
Well-Known Member
Very thorough and in-depth analysis of how this system works. Although probably over most of our understanding.
The main reason for using CHMSL location is this is the only location in the cab to get at the brake light signal without taping into the wiring harness, or creating a huge T-harness for 2 wires under the dash. Something Ford would not allow, and could not do for safety reasons. Definitely a design miss by Ford.
I may be wrong, and probably am, but I believe the Lumen module is used for signal conditioning of the PWM signal used, for whatever reason, and isolation of any voltage from the TBC getting backfed to the PCM.
Now to my issues with the suggestion of tapping into the brake light signals from the TRM. The problem with this is. Do to the, let's call it outdated, wiring standards for trailer wiring. The outputs from the TRM have the brake lights and the turn signals combined into the same wire. This means which ever side you tap into, whether at the TRM or the 7-pin connector, will cause the trailer brakes to pulse when the turn signal for that side is activated. This an issue that any plug mounted or trailer mounted brake controller must deal with.
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