brakes and shifting?

phish finder · Jan 19, 2010

My '04 Titan will not shift without manually engaging the brake controller. Any ideas where to start the troubleshooting?

The brakes work but it appears that the signal isn't being sent to the transmission.

mde's04titan · Jan 19, 2010

So, you must be talking about the downshifting/engine braking function. Who hooked it up? I would first take it back to them. I've not heard of this problem from anyone until now....

Carbeaux · Jan 19, 2010

I'm not sure what you mean. Stepping on the brake pedal doesn't allow you to shift out of park? And the only way you can do that is to put on the parking brake?

phish finder · Jan 20, 2010

1) correct, stepping on the brake pedal doesn't allow me to shift out of park
2)incorrect, parking brake is not touched. Engaging the brake controller manually allows me to shift to/from park

phish finder · Jan 20, 2010

Sorry about the confusion, busy day.

I installed a brake controller in the spring for towing a travel trailer. It has worked fine for 10k miles of driving around Alaska. Last night, I drove to the local grocer. When I stopped at the grocer, I could not shift the truck into R or P. I put the truck into N and engaged the parking brake.

After reading up on it a bit, I went back and activated the shift lock release (pulled cover and pushed in). This allowed me to get the vehicle home. When I returned home, I attempted to troubleshoot the problem. The only thing in the manual that I could find was that the vehicle only shifted from P and into P with the brake pedal depressed.
This detail led me to believe that the brake controller may have a problem and wasn't allowing the signal to be sent (wherever it goes) to allow the transmission to shift to/from P. Nothing happened when the brake controller was disconnected. I checked the connections and the brake controller appeared to have no problems.
I reconnected the brake controller and activated the manual brake control. This allowed the transmission to shift like normal.

So, to clarify my earlier post, activating the brake controller (which I installed) allows the transmission to shift to/from P. Otherwise, I can't shift from P to R or N to P.

What should I do next?

jscsir10 · Jan 20, 2010

did you try disconnecting the brake controller from the truck and trying to shift from park into any gear and back into park with the brake pedal yet?

mjw357 · Jan 20, 2010

Disconnect brake controller temporarily, see if symptoms go away.

Carbeaux · Jan 20, 2010

^^^That's definitely worth a shot. And it's easy. Easy is good.

phish finder · Jan 20, 2010

I started another thread earlier today.

After getting the truck home, I disconnected the brake controller. Truck unable to shift.
tested brake controller wiring and brake controller with multimeter. brake controller is fully functional
reconnected brake controller, still unable to shift
manually activated brake controller, truck shifts as normal

So, manually activating the brake sends the required signal. This leads me to assume that the pedal isn't sending the required signal to the transmission. Without a diagram, tearing into the wiring would be a nightmare and potentially lead to more problems. I can't stand dealing with dealerships so I was hoping this problem happened before and there is a fix that I can perform.

I appreciate any help you guys can provide

Carbeaux · Jan 20, 2010

There's a switch above the brake pedal. Is it working? Time for that multimeter again.

Edit: And I don't think that signal goes to the trans. There's a solenoid that is activated to allow the shifting.

phish finder · Jan 20, 2010

Carbeaux said:
There's a solenoid that is activated to allow the shifting.

I'll go out and check that now. I'm more of a hands on guy so I stink at describing what I'm attempting to describe. Thanks for the clarification.

Carbeaux · Jan 20, 2010

You should actually be able to hear it engaging and disengaging, especially if you try it without the truck actually running.

mde's04titan · Jan 20, 2010

There's a switch not being activated on the brake pedal that you are simulating the same signal with the controller. It's just like the brake controller, when manually engaged, will illuminate the brake lights, even when the pedal is not touched. The switch needs adjusting, that's all. I bet you haven't had brake lights either, and just didn't notice.

Have you had to slam on the brakes lately? I mean like really hard....it may have moved the switch a little where normal pedal pressure just doesn't make it function.

This is also the same wire a lot of people tap into when doing the burnout mod, and also use it as an anti-theft type switch. Because if the brake lights don't illuminate, it won't come out of park--just like what is presenting itself as a problem with you.

phish finder · Jan 20, 2010

mde's04titan said:
The switch needs adjusting, that's all.

Is that an adjustment that I could make?
I see two pressure switches that release when the pedal is depressed. They both seem to release normally. I don't know which does what. Any ideas which of the two sends the signal to the solenoid?

mde's04titan · Jan 20, 2010

Mash them individually with a screw driver or something, and see which one turns the lights on. That's where the issue is, I'd bet.

phish finder · Jan 20, 2010

Both switches function by releasing pressure. I released both switches by fully depressing pedal, then manipulated both switches with a pair of pliers. I was unable to get any results by manipulating the release. Would there be a fuse in the circuit?

mde's04titan · Jan 20, 2010

All of this of course is assuming that the brake controller was/is installed correctly. Grab the manual control again, and make sure that it illuminates the brake lights with nothing touching the pedal itself. If installed correctly, it will, if not.....uninstall it and start over, because it really needs to be that way to be safe! If it does, then this sounds like a simple switch adjustment on the pedal itself. And if it got out of wack that easily, it should be relatively easy to get it back to good!

Carbeaux · Jan 20, 2010

The manual control on the EBC will not illuminate the brake lights on the truck. I just went out and verified this on mine.

mde's04titan · Jan 20, 2010

Huh???? I think every one I have ever had does. That way if you pull it instead of the pedal, like to cancel some sway, it illuminates the brake lights. It's also how I scare the chit outta people riding my rear, without actually braking. Maybe it's relay controlled??? Was your truck running? I say this because my parking lights on my trailer will NOT flash when I lock/unlock my truck, but of course they work when the headlights are on.

Carbeaux · Jan 20, 2010

Truck was running. I don't think my trailer lights flash with the lock/unlock feature either, but I won't swear to that.

titanridinghigh · Jan 20, 2010

Its the bottom switch that activates the brake lights and shift release.
I managed to open mine up and push the metal taps in a little, but that only worked for so long.
You can go to your local nissan dealer and pick up a new activator switch, like I ended up doing, for $40

mde's04titan · Jan 20, 2010

Just went out and checked mine, and even with the key OUT OF THE TRUCK, the EBC illuminates the lights----AS IT SHOULD for safety reasons. This is a fundamental. If engaging trailer brakes, wouldn't you want the lights on????? Carbeaux, you may have an issue??

Carbeaux · Jan 20, 2010

I don't believe so. It was the same in the other vehicle the Prodigy was installed in. Trailer brake lights work flawlessly with the brake pedal. The Prodigy was installed with a pre-wired Prodigy/Titan harness.

Edit to add: It might with the trailer lights, when the trailer is hooked, but why would I want my truck tails illuminating when I manually activate an EBC with no trailer hooked up? It's not braking my truck. :lol:

mde's04titan · Jan 20, 2010

I've pulled many a trailer, on many a truck, and although I wouldn't swear to it, I believe they all have worked in the manner I stated, and for the reason I stated. I know 4 of them right off the top of my head that were exactly this way, and 2 of them weren't mine.

Maybe yours is "smarter" or newer than anything I've had and knows to only send the current for the lights to the trailer, and not the rig. I'm perplexed by this indeed.

Carbeaux · Jan 20, 2010

Fourth trailer for me, third tow vehicle. And the BEST tow vehicle I might add.

Carbeaux · Jan 20, 2010

I LOVE that EBC. Hands down better than the first one I had. I don't even remember what that piece of junk was, but I know it was a bugger to get set right. Manual leveling and all that. The Prodigy is a no brainer.

To the OP. I don't think there's a fuse between that switch above the pedal and the solenoid. Were you able to test for current when you activated the switch?

brakes and shifting?

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