Plz help, does my DAC work properly?

[pwanghk]

Greetings:

In order to test the DAC function wiht my 04 4Runner Sport Ed, I perform the following steps:

1. Vehicle is completely stop at traffic light with shift lever in D position.
2. Turn the 2, H4, L4 knob all the way to L4 position.
3. The 4x4, LO4 indicator lights up with a continuous sound in the cabin.
4. Engage the DAC switch and start driving downhill on a 30~40% slope about 1 miles long.
5. The DAC indicator is blinking, the SUV get momentum and keep accelerating downhill, I have to pump the brake intermetently to keep the speed below 35mph.

Do I perform this correctly? If so, what is the DAC suppose to do?

Your input is greatly appreciated.

 

[Guest]

Explaination here and in your manual-good luck!

 

[dancojgl]

In order to test the DAC function wiht my 04 4Runner Sport Ed, I perform the following steps:

1. Vehicle is completely stop at traffic light with shift lever in D position.
2. Turn the 2, H4, L4 knob all the way to L4 position.
3. The 4x4, LO4 indicator lights up with a continuous sound in the cabin.
4. Engage the DAC switch and start driving downhill on a 30~40% slope about 1 miles long.
5. The DAC indicator is blinking, the SUV get momentum and keep accelerating downhill, I have to pump the brake intermetently to keep the speed below 35mph.

Do I perform this correctly?

No, you never actually got out of 2H...The flashing 4x4 and LO4 lights and the alarm buzzer indicate that the 4WD system didn't shift into LO4.

You got up to 35 mph because DAC didn't engage either, since the vehicle has to be in 4LO first...

To go to LO4, you have to be stopped, with the transmission in NEUTRAL. Then you can go to "D".

If so, what is the DAC suppose to do?

DAC (Downhill Assist Control) uses your antilock brake system to keep the speed of your vehicle under 4 mph (3mph +/- 1mph is the spec, IIRC).

DAC actually works better if you downshift from "D" to "L" in 4LO, that way it can use engine braking as well, saving brake wear and reducing brake heating.

Try it again, going into 4LO while in NEUTRAL. You'll know when DAC is working

 

[pwanghk]

Thank you all for your help.

dancojgl: I try it and it's so scary. With all the cracking loud noise, I didn't dare to continue for more than a couple of feet. I don't know if I actually broke it or the sound is natural (I sincerely hope that it is natural ). I will check with the dealer on Monday. If it is broken, I think Toyota designer must put some sort of safety and should show it on a video or when deliver the SUV to you. This way, you would know how to operate the device properly.

 

[dancojgl]

Don't worry, you didn't break it. The horrible racket is perfectly normal.

DAC uses your ABS system, which makes a lot of noise when it fires. It's automatically pumping your brakes several times per second, and sounds like a machine gun going off.

Find a nice long, steep hill and give your DAC a good workout. You'll soon realize that it DOES work, and it's nothing to be afraid of....You just need to crank up the stereo a little louder!

Enjoy,

 

[pwanghk]

Thank you so much for reassuring me. What I was hearing during my first test does sound like your description . I cross my finger and hope that you're right once more.

 

[mtnrunner]

I tried my DAC on a steep dirt road with lots of loose rocks but I don't think the road was really steep enough as the incline did not allow the 4R to ever achieve a constant rate of descent, instead, it would come to a near stop until I hit the gas.

Yea, a bit disconcerting to hear all that racket. I think the only real value to DAC will be on icy or muddy roads with a good incline...

 

[Thai]

Get used to the noises...it's just the ABS system pumping the brakes.

 

[Guest]

I tried my DAC on a steep dirt road with lots of loose rocks but I don't think the road was really steep enough as the incline did not allow the 4R to ever achieve a constant rate of descent, instead, it would come to a near stop until I hit the gas.

Yea, a bit disconcerting to hear all that racket. I think the only real value to DAC will be on icy or muddy roads with a good incline...

You have not gotten close enough to the steep, rugged terrain the DAC was designed for. It's not intended for roads. Usually there are no roads (paved or dirt) with a grade steep enough to use DAC.

 

[mtnrunner]

That's what I figured. Just had to test it though. I'm sure I'll be flipping it on once the oppurtunity arises, like on frozen forest access roads going back country sking. It's just good to know it's there and good to know how to engage it...

 

[Guest]

That's what I figured. Just had to test it though. I'm sure I'll be flipping it on once the oppurtunity arises, like on frozen forest access roads going back country sking. It's just good to know it's there and good to know how to engage it...

:thumb:

 

[Greenhorne]

Re: Re: Plz help, does my DAC work properly?

Try it again, going into 4LO while in NEUTRAL. You'll know when DAC is working

 

[Greenhorne]

Find a nice long, steep hill and give your DAC a good workout. You'll soon realize that it DOES work, and it's nothing to be afraid of....

Until you accidently touch the brake unwillingly and arn't prepared to be in command again. The the pucker factor is in effect for a moment.

 

[pwanghk]

Just come back from the dealer and test drive with a technician to make sure that I am not breaking something. Everything is fine according to him. The loud noise is so intimidating when I first heard it. Now I know how it does work.

Thank you all for your help.

 

[Good Times]

loud noise

If you want to hear some loud stuff, you should come on some day trips with me where you will hear lots of interesting sounds