Are your brakes engaging after letting off full throttle?

[7TH_SIGN]

I've done a search and came up with nothing so this may just be me.

When I go 100% throttle and let off immediately it feels as if the brakes are engaging. During night driving I can see the rear brake lights come on. I'm not touching the brake peddle. Anyone experience this?

Thank you.

[LABrit]

Doesn't sound right...until you said you see the rear brake lights come on i was going to suggest it was simply engine braking. Need to go take it in.

[donk_316]

I've seen this before!
There is a vendor who has vids of his exhaust, they do a drive by and under full throttle he lets off and the brake lights flash. I always wondered why he taps the brakes... This sounds like the exact same thing.

[7TH_SIGN]

I apologize for the thread, had a friend just send me a link to a previous thread. $20 brake light switch. May just order it and replace it my self. My car however does feel as if its slowing down when the brake lights come on. So I do think my brakes are engaging when this happens.

http://driveviper.com/forums/threads/9023-Brake-lights-flashing-while-shifting?highlight=brake+lights+flashing

[swexlin]

No issues with mine.

[Darius]

Yes! My 2014 TA did this and my 2016 ACR does it also. Very noticeable if you smash on it in 1st gear and shift slowly to 2nd. I can feel it drag. I also saw a video of my ACR doing the half mile and saw the brake lights come on.

[Rapidrezults]

I thought I remembered reading that this was some kind of glitch in the hill control system. Maybe the rapid acceleration gives the sensors the reading that you are on an incline and engages the hill control (brakes) when you let off the throttle completely during rapid acceleration. This would make sense during slow shifts. I've see many many videos with this happening on Gen Vs so I can't see it just being a faulty switch. It's probably related to driving style more than anything. Who knows...

[7TH_SIGN]

I'll try disabling the hill assist first. I can feel the car slowing down when it happens. I don't think its brake peddle related but rather some kind of glitch.

[SRT BILL]

Take a look at the tail lights on the Viper in the right lane at the times the video suggests. They blink at every shift, i've noticed this in some other vids also. It could the hill assist thing in action. Have to wonder what they would have run without that brake light coming on. https://youtu.be/uGvEePHrMlo

[Ninjakris]

I seen videos of my car flashing brake lights between shifts at 1/2 mile events. It's never really bothered me enough to do something about it.

[7TH_SIGN]

Just took mine out for a test with hill asset disabled and it still was doing it. maybe it is in fact a bad brake light sensor.

[Rapidrezults]

Just took mine out for a test with hill asset disabled and it still was doing it. maybe it is in fact a bad brake light sensor.
Try running it with TC and ESC full off and see if you feel the brakes still engaging. I guess there are two problems here, the brake light and the brakes actually engaging.

[Jack B]

The brake light coming on during shifts has been a common problem from day one. The brakes actually engaging is new or rare. My Grand Cherokee has collision braking and every now and then, it does apply the brakes, but, just for a millisecond.

[7TH_SIGN]

Try running it with TC and ESC full off and see if you feel the brakes still engaging. I guess there are two problems here, the brake light and the brakes actually engaging.

I will try that the next time out.


The brake light coming on during shifts has been a common problem from day one. The brakes actually engaging is new or rare. My Grand Cherokee has collision braking and every now and then, it does apply the brakes, but, just for a millisecond.

I can't be certain as of yet but it really feels as if they are engaging. I may be wrong.

Found another thread on the topic. Looks to be the switch again. Going to order and new one and install. Will report back.

Thanks

http://driveviper.com/forums/threads/9469-Brake-lights-come-on-momentarily-during-hard-shifting

[Darius]

It's annoying that I buy a car 2 years newer than the last and it's doing the same thing. Also to notice it you have to go wot to the top of 1st and let off. Not the kind of thing you want the tech at the dealer doing on the street.

[7TH_SIGN]

It's annoying that I buy a car 2 years newer than the last and it's doing the same thing. Also to notice it you have to go wot to the top of 1st and let off to notice it. Not the kind of thing you want the tech at the dealer doing on the street.

Yeah I know what you mean brother. This is why I opt to do as much of the recalls and warranty repair myself. I just don't trust the dealerships in my area. Fortunately I'm good friends with a parts manager near me. He is usually able to get me the needed parts under warranty and I just take it home and do it from the safety of my own garage. This part only costs $20. Should be an easy swap.

[7TH_SIGN]

**Fixed**

Had sometime to mess with the brake light sensor today and figured I'd try to fix it before ordering a new one. It is very limited to adjustment but I was able to adjust it enough to eliminate the issue. There is a medal plate that makes contact with the black plastic brake light sensor. When you push the brake peddle this move the metal plate forward which then moves the black plastic sensor forward enough to turn the brake lights on.

If the issue comes back I'll just order a new sensor. Very easy fix nonetheless. I added pics and a video for those who rather take care of this at home.

http://i882.photobucket.com/albums/ac26/7THSIGN_photos/8792D080-16B3-4662-BAFF-E7FAF7D8A843_zps4tttbvow.jpg

http://i882.photobucket.com/albums/ac26/7THSIGN_photos/7635C60A-0335-4124-8F78-81B38531432E_zpstgfpbuqq.jpg

http://i882.photobucket.com/albums/ac26/7THSIGN_photos/415DD266-A46A-43B4-A13E-94C4003288F2_zpsitvf2yw2.jpg

http://i882.photobucket.com/albums/ac26/7THSIGN_photos/th_7CF517C2-144C-4C0B-A60E-02D102944EE4_zpslpi09jrc.mp4 (http://i882.photobucket.com/albums/ac26/7THSIGN_photos/7CF517C2-144C-4C0B-A60E-02D102944EE4_zpslpi09jrc.mp4)

[Darius]

Does that fix the brake dragging also?

[Malu59RT]

I've always noticed this when all my ESC/TC was on, and it may be mental, but I think it was less noticeable when they were off. This is why no-lift shifting is so important in the car when drag racing. Wish there was a solution to that.

7th_sign, as far as the light flashing between shifts, I remember Mark Jorgensen saying that adjusting it won't be a long term solution, it will eventually act up again and the switch will need to be replaced. Curious to see if your outcome will be any different, but good luck!

[7TH_SIGN]

Does that fix the brake dragging also?

I still can't determine if this is happening or not. Do you feel yours is doing it?


I've always noticed this when all my ESC/TC was on, and it may be mental, but I think it was less noticeable when they were off. This is why no-lift shifting is so important in the car when drag racing. Wish there was a solution to that.

7th_sign, as far as the light flashing between shifts, I remember Mark Jorgensen saying that adjusting it won't be a long term solution, it will eventually act up again and the switch will need to be replaced. Curious to see if your outcome will be any different, but good luck!

I believe Mark is correct Malu59RT and the issue will present its self again. The room for adjustment was extremely little and really just consisted of bending the metal plate and moving the sensor ever so slightly. The good news for us is the part only costs $20.

[SRT BILL]

7th do you mind sharing the part number?

[The_Ruski_Driver]

Anyway to know for sure if your brakes are indeed engaging or if it's just a light?

[7TH_SIGN]

Did my second oil change. Just hit 1000 miles on it. No visible metal/aluminum shavings in the oil like the first one at 500 miles.

So my brake light issue wasn't solved like I earlier thought.

Here is a short video from today's cruise. Really enjoy the GEN V Viper. Well done Dodge! Best shifting car I've ever owned.


https://www.youtube.com/watch?v=Le4vH9lQHpU

[7TH_SIGN]

I've replaced the brake light switch twice and still no resolve.

I've determined that the brake lights come on when I let off after having the throttle pedal fully down to the floor board. This doesn't have anything to do with the cars momentum moving forward as I can be in 6th gear and do it while the cars weight stays almost level.

Any ideas? I really want to avoid taking it to the dealership but if no one here has any ideas I may just have to do that.

[Rapidrezults]

I've replaced the brake light switch twice and still no resolve.

I've determined that the brake lights come on when I let off after having the throttle pedal fully down to the floor board. This doesn't have anything to do with the cars momentum moving forward as I can be in 6th gear and do it while the cars weight stays almost level.

Any ideas? I really want to avoid taking it to the dealership but if no one here has any ideas I may just have to do that.

So when you replaced the brake light switch, did it solve the problem for a period of time and then resurface, or was it never fixed to begin with? Are you saying that the problem in your opinion has nothing to do with the brake light switch after all?

[7TH_SIGN]

So when you replaced the brake light switch, did it solve the problem for a period of time and then resurface, or was it never fixed to begin with? Are you saying that the problem in your opinion has nothing to do with the brake light switch after all?

Yes sir that's correct. The issue is not the brake light switch. I thought I had fixed it however I was wrong. The lights come on when I lift off the throttle after having it to the floor board, no matter the speed and momentum.

[EZ 2B Green]

7th, just so it's clear to all of us, did you disconnect the brake light switch completely when you did your last test? This seems like it would clearly be a computer issue if the brake lights come on without the switch.

[aNinjaneer]

Can someone confirm that this is a bug, and not a feature? Every Gen V I've seen does this, and I believe it's a feature of deceleration to alert drivers behind you that you're slowing, whether you're braking or not. I'll look through the service documentation to see if this is the case, but I think this is how it is supposed to operate.

[SSGNRDZ_28]

Can someone confirm that this is a bug, and not a feature? Every Gen V I've seen does this, and I believe it's a feature of deceleration to alert drivers behind you that you're slowing, whether you're braking or not. I'll look through the service documentation to see if this is the case, but I think this is how it is supposed to operate.

I've been thinking this as well. Sudden off throttle flashes the lights as a warning to those behind.

[Rapidrezults]

Can someone confirm that this is a bug, and not a feature? Every Gen V I've seen does this, and I believe it's a feature of deceleration to alert drivers behind you that you're slowing, whether you're braking or not. I'll look through the service documentation to see if this is the case, but I think this is how it is supposed to operate.

I'm really starting to think this is the case. It doesn't make sense that every single Gen V I've seen does this as well.

[Darius]

I turned off the hill assist and I believe it went away.

[kverges]

Does the Solo DL have the ability to log brake pressure? If so I'd love to see the traces.

[7TH_SIGN]

7th, just so it's clear to all of us, did you disconnect the brake light switch completely when you did your last test? This seems like it would clearly be a computer issue if the brake lights come on without the switch.

When I disconnected the brake light switch, the rear brakes stayed on.


Can someone confirm that this is a bug, and not a feature? Every Gen V I've seen does this, and I believe it's a feature of deceleration to alert drivers behind you that you're slowing, whether you're braking or not. I'll look through the service documentation to see if this is the case, but I think this is how it is supposed to operate.

I've seen some do it and some that don't. For example going down the 1/4 mile. Thanks for checking in to that.


I turned off the hill assist and I believe it went away.

I disabled hill assist however it didn't work.

Its strange that it only happens when you push the throttle down all the way and let off suddenly.

[ViperSmith]

Are brakes actually being applied by the car (even if minor) or is this just a wild goose chase of the circuitry triggering the lights?

[7TH_SIGN]

Are brakes actually being applied by the car (even if minor) or is this just a wild goose chase of the circuitry triggering the lights?

I honestly feel they are.

[bluesrt]

im surprised no techs have chimed in on this

[darbgnik]

I would think it would be impossible to tell the difference between the brakes engaging a tad, vs instantaneous engine braking, knowing that at high RPM, with abrupt lift off of the throttle, the engine braking would be at it's absolute highest........

[38D]

If you want to prove the brakes are engaging, rent a data system and get a brake pressure reading. Short of that, I'd tend to agree that high RPM engine braking seems a more likely cause.

[7TH_SIGN]

I would think it would be impossible to tell the difference between the brakes engaging a tad, vs instantaneous engine braking, knowing that at high RPM, with abrupt lift off of the throttle, the engine braking would be at it's absolute highest........


If you want to prove the brakes are engaging, rent a data system and get a brake pressure reading. Short of that, I'd tend to agree that high RPM engine braking seems a more likely cause.

I side with you both. I'm coming from a inline 6 lol. I feel the car slowing down for sure when it happens but it may just be the engine like you state.

[Darius]

I honestly feel they are.

I'm 100% sure they are also. I can definitely feel drag when I do a hard 1st gear pull and let off.

[Darius]

I would think it would be impossible to tell the difference between the brakes engaging a tad, vs instantaneous engine braking, knowing that at high RPM, with abrupt lift off of the throttle, the engine braking would be at it's absolute highest........

It's not engine braking, you can push the clutch in before you let off and still feel the deceleration.

[38D]

It's not engine braking, you can push the clutch in before you let off and still feel the deceleration.

Could it be the aero drag? People who drive F1 cars always comment on how fast those cars decelerate just from lifting off the throttle. ACR is not quite in the same league, but does have way more aero than normal.

[CarolinaViper]

Is traction control on or off...maybe this has something to do with it...just a thought

[7TH_SIGN]

Is traction control on or off...maybe this has something to do with it...just a thought

I've tried disabling it but it still does it.

[EZ 2B Green]

When I disconnected the brake light switch, the rear brakes stayed on.



I've seen some do it and some that don't. For example going down the 1/4 mile. Thanks for checking in to that.



I disabled hill assist however it didn't work.

Its strange that it only happens when you push the throttle down all the way and let off suddenly.

In that case, it must be a normally closed switch. I would try shorting out the switch connection so the brake lights are off and then do your high speed run and let off the throttle to see if the lights come on. Of course you will have no brake lights from the pedal during this test so do it in a safe place. If they do come on then the braking must be from another source such as the computer.

[Sniper]

Was there ever a fix for this?

[Old School]

Skip to the end, when they're actually racing and you will see the brake light come on...

https://www.youtube.com/watch?v=YcMDpukTM0k

[Steve M]

Skip to the end, when they're actually racing and you will see the brake light come on...

https://www.youtube.com/watch?v=YcMDpukTM0k

Dude had to have hit the brake pedal both times on the 1-2 shift - his nose dove HARD both times, and only on that shift. He may not have been aware of it at the time, but it would be pretty easy to do, especially with how close the pedals are.

My Gen 4 definitely doesn't do it, even with my slow shifting. You can see the nose drop on mine on the 1-2 shift as well, but no brake lights. I can't see them adding this "feature" to a Gen 5, especially since it didn't happen again for the rest of that guy's run. Skip to 1:00 to see my actual pass:


https://youtu.be/A523mJ_FWZI

[Sniper]

Was there ever a fix found for this?
Here’s a video of it happening to my 2013.


https://youtu.be/9F698dtmng4

[Polished]

Has anyone ever fixed this problem? I picked up a viper about 6 months ago and the brakes are definitely engaging between shifts (not every time though).

[ViperGeorge]

I have been under the impression that the brake lights coming on while shifting had to do with conservation of momentum of the brake pedal. I think that when you shift the acceleration of the car is interrupted ever so slightly. Due to tire friction, engine braking, and the slight brake drag inherent in disc brake systems the car's forward acceleration would be interrupted. However the forward momentum of the brake pedal would remain since it is free to move independent of the car's movement. Continued forward movement of the brake pedal could engage the switch since the switch is very sensitive and has close tolerances.

Well at least that is my theory. In terms of the brakes actually engaging I would check if the brakes are in fact too tight when the car is not moving. Jack up the car remove the front tires and then try to rotate the rotors. You should feel some light drag but they should turn pretty freely. The rears would be harder to check since they are the driven wheels. If there is a lot of drag the pads might be binding. I always grind down the edges of new pads before installing them. Once I failed to do this and the backing plate on the pads warped because they were getting bound up.

[Arizona Vipers]

It's definitely the brake switch. If you watch my track videos, my smarty cam overlay shows the braking and it shows the brakes depressed when they aren't. Hard deceleration from letting off at high speed is enough to push the brake pedal in enough to hit the switch.

[ViperGeorge]

It's definitely the brake switch. If you watch my track videos, my smarty cam overlay shows the braking and it shows the brakes depressed when they aren't. Hard deceleration from letting off at high speed is enough to push the brake pedal in enough to hit the switch.

Is your Smarty Cam reading off the brake switch? Final proof would be to hook up a pressure sensor. This can be done with the Racelogic HD2 system but I haven't done it. You could then verify beyond doubt that the pressure in the brake lines isn't changing when shifting indicating that the brakes are not engaging. Complete Performance has done this if they are on here maybe they could chime in.

[Arizona Vipers]

Is your Smarty Cam reading off the brake switch? Final proof would be to hook up a pressure sensor. This can be done with the Racelogic HD2 system but I haven't done it. You could then verify beyond doubt that the pressure in the brake lines isn't changing when shifting indicating that the brakes are not engaging. Complete Performance has done this if they are on here maybe they could chime in.

Did Complete find any cars that the brakes were indeed engaging a bit? Man I hope mine has been doing this all these years and car should be faster if I get it fixed hehe. Not sure how the smarty cam reads it, I'm assuming the OBD port, not sure if it gets that info from the sensor or what...

[ViperGeorge]

Did Complete find any cars that the brakes were indeed engaging a bit? Man I hope mine has been doing this all these years and car should be faster if I get it fixed hehe. Not sure how the smarty cam reads it, I'm assuming the OBD port, not sure if it gets that info from the sensor or what...

I don't know if Complete found any cars that were engaging the brakes, I never asked. You need to put an inline pressure sensor in the brake line in order to get the brake pressure to show up in your data collection app. The Viper's OBD II stream does not provide brake pressure according to Complete and they use AIM on their cars.