Any way to bomb the exhaust brake to stay on?

[UpstateNYoilburner]

I had the old school push/pull switch mounted on the stick on my '05, and liked that you could just leave it on all the time. Has anyone found a way to do that with the dash switch?

I would rather it be on all the time, and turn it off when things get slick.

Thanks

Matt

 

[Powder Extreme]

In the first setting "non auto" the brake will come on every time you let your foot off the accelerator. When you say on all the time, isn't that what you mean? If you mean how it will cut off at low speed, putting the truck in tow/haul mode will leave the brake engaged longer, almost to a complete stop.

 

[BILLUA]

i think he is asking if he can wire it so that he doesn't have to push the EB button to arm it every time he starts the truck.

I would like to be able to do that also.

 

[UpstateNYoilburner]

You are correct Billua, that's what I'm looking for.

 

[Sticks]

Without seeing a wiring diagram, the obvious would be to tap into the relay circuit (if it has a separate relay) to add a second switch to the relay coil. If it is controlled directly by the ECM/PCM or TIPM (no relay), then you would probably need to tap into the wiring directly at the switch, but you would need to know if it is controlled by the hot leg, or ground.

The only access I have to anything resembling a wiring schematic is AllData, and they have nothing for 2010 and up.

 

[slingshot383]

Since it's a momentary button that turns on the exhaust brake, you would need a momentary relay that triggers off the release of the engine start position of the key (or the command signal for the keyless start trucks). You would need the wiring schematic for the truck in order to do this.

 

[RVTRKN]

Do a search in "6. 7 engine and transmission" forum, there has been successful attempts at doing this in the early 3rd Gen trucks with the 6. 7. If my truck wasn't a C&C, that keeps the EB on all the time regardless, I would look for a remedy on this as well. The owners of regular pickups with 6. 7's have just gotten used to turning it on, like remembering to set the emergency brake every time you park. Also I recommend keeping it on all the time to help keep the turbo clean.

 

[Powder Extreme]

i think he is asking if he can wire it so that he doesn't have to push the EB button to arm it every time he starts the truck.

I would like to be able to do that also.

Ah! That would be nice! And tow/haul mode while we're at it! At least they finally leave the park assist as you set it. My friggin GMC tells me my rear sensors are blocked constantly. Even AFTER I've turned them off with a trailer hooked up. Going 20mph forward it will ding and the EVIC will tell me the sensors are blocked. Thanks, important info I need to know while going forward at 20mpj!

 

[Powder Extreme]

Considering the new trucks have a three setting brake with the push of one momentary button (on, auto, off), I would think your best bet would be trying to keep power to that button all the time so it thinks the truck is never shut off. Otherwise it's got to be going thru the PCM, since its not working as a simple on/off switch. However when the PCM sees the key off signal, I get it will reset it anyway.

 

[UpstateNYoilburner]

Hmmm, so maybe a constant 12v vs ign on would do the trick??

 

[Bob V]

Be aware that the trucks computer does not look for "on or off" each switch has a resistance value and that is what is what the computer looks for.

 

[RVTRKN]

As long as you know that value, and a simple ohm test will tell you that. Rig a momentary relay that operates when ignition is turned on in parallel with the OEM switch, and set up the relay with a time delay so it gives the time needed for starting. But not knowing how it works I'm willing to bet its just a grounding signal to the ECM, and grounds the circuit turning it on and opening the circuit when off.

 

[n7gxz]

The switch for the EB is just like a key on your computer keyboard. When you push the EB button it just sends a computer signal out on the CANBus network that the PCM/ECM pick up on and then turn on the EB circuit. Dodge doing some CYA choose to set the default to be EB off at startup with no option to change the default without hacking the PCM/EMC software.

Kevin

 

[MelvinPierce]

It stays ON, IF you have a trailer connected. Take the trailer off, and the EB goes OFF when you turn the truck off. I have a '14 3500DRW.

Maybe you can make up a trailer plug, that mimicks the trailer being there, and trick the ECM into thinking you have a trailer hooked up all the time?

 

[Powder Extreme]

It stays ON, IF you have a trailer connected. Take the trailer off, and the EB goes OFF when you turn the truck off. I have a '14 3500DRW.

Maybe you can make up a trailer plug, that mimicks the trailer being there, and trick the ECM into thinking you have a trailer hooked up all the time?

Wait, so if I'm understanding you, if you have a trailer plugged in and the brake is on when you shut the truck off, it will still be on when you start the truck later? That's new, mine I have to turn the brake on and put it in tow haul mode every time I start it. Even though a trailer is hooked up. Will yours stay in tow haul mode as well?

 

[MelvinPierce]

Wait, so if I'm understanding you, if you have a trailer plugged in and the brake is on when you shut the truck off, it will still be on when you start the truck later? That's new, mine I have to turn the brake on and put it in tow haul mode every time I start it. Even though a trailer is hooked up. Will yours stay in tow haul mode as well?

The exhaust brake stays on with the trailer connected, however, the tow/haul mode goes off with the engine. We hooked to the trailer right away, and took off. I noticed, and commented to the wife, that the EB was staying on, when turned off fueling.

We unhooked the trailer, and all of a sudden the EB was off, when the engine was off. When we hooked the trailer back up and came home, the EB stayed on again with the engine off.

 

[AH64ID]

I know that some people devised a wiring schematic to do so on the 3rd gens, but honestly I wouldn't recommend it.

It puts a big load on the engine as soon as you start it, and has the potential to push exhaust past the cold rings into the oil. I know on my 05 when I use the EB to warm a cold engine the soot in the oil goes up very quickly. Since the 6. 7 monitor back pressure and appears to adjust the idle backpressure it doesn't happen as quick, but starting and going instantly to EB seems like it would be harder on the motor than letting it run for a little and turning it on.

 

[MelvinPierce]

I know that some people devised a wiring schematic to do so on the 3rd gens, but honestly I wouldn't recommend it.

It puts a big load on the engine as soon as you start it, and has the potential to push exhaust past the cold rings into the oil. I know on my 05 when I use the EB to warm a cold engine the soot in the oil goes up very quickly. Since the 6. 7 monitor back pressure and appears to adjust the idle backpressure it doesn't happen as quick, but starting and going instantly to EB seems like it would be harder on the motor than letting it run for a little and turning it on.

The EB is ON, even if not moving? I thought you had to be moving, and back off throttle, and/or use brakes for it to be applied. I never noticed that with the trailer hooked up, and the EB switch staying on over night, that it was applied to the exhaust, just sitting there after starting up.

 

[AH64ID]

The EB has a warmup mode, and will be on if the coolant and ambient temp are low enough.