What is your experience with Hill Start Assist?

Hill Start Assist Control is a feature designed to help minimize backward rolling on steep ascents.

Toyota's documentation lists the feature as Standard on EVERY trim level:

^ source

* TRD Off-Road 4WD M/T is the only trim documented to not have the feature:

^ source

So what's the problem?

• Most people report the feature immediately and firmly holds the vehicle in place for 2 seconds. This is what would be expected from anyone who has used this feature on a prior vehicle.

• Others report that the vehicle creeps backwards while the vehicle makes noises instead of being held in place.

I am trying to figure out which of these is actually expected, and how common each observation is.

**UPDATE**
It appears to be broken down like this:
- A/T with slow creep backwards and noise is only TRD Off-Road (maybe also TRD PRO) A/T
- M/T with slow creep backwards is only TRD Off-Road 4WD (maybe also TRD Pro) M/T
- A/T held firmly is every other trim
- M/T held firmly is every other trim

If you have a different experience with this feature please let me know; also include your Trim level (SR/SR5/TRDS/TRDOR/Limited/TRDPRO).


How does it work? From the manual:



Here are the previous threads on this topic i have reviewed:
https://www.tacomaworld.com/threads/hill-start-assist-control.422486/
https://www.tacomaworld.com/threads/hill-start-assist-sucks-why.107824/
https://www.tacomaworld.com/threads/hill-start-assist.399682/
https://www.tacomaworld.com/threads/hill-start-assist-issues.459710/

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http://www.toyota.com/tacoma/ebrochure/ lists every trim level as including:
"• Hill Start Assist Control (HAC)30 (A/T only)"

http://www.toyota.com/tacoma/features/safety_convenience/7594/7544/7582/7598 says:
"Hill Start Assist Control is designed to help minimize backward rolling on steep ascents. It is not a substitute for safe driving judgment and practices. Factors including grade, surface conditions and driver input can all affect whether HAC will be effective in preventing a loss of control. "

http://www.toyota.com/tacoma/ says:
"
Hill Start Assist Control
Tacoma’s Hill Start Assist Control (HAC) 18 helps you safely get up those hills. This technology helps minimize Tacoma from rolling backward when you move your foot from the brake to the gas pedal, so you can move upward with confidence. (HAC not available on TRD Off-Road 4WD M/T.)
"

-------------

 

works good, i like it on my 2.7 MT. i didnt know what it was at first hahaha, but it works good.

 

here in DFW there is not much hills - so my experience is limited to small hills - it works great

 

It has always been less than 2 seconds for me, but now that I read the conditions I may be canceling it early by getting on the accelerator. Next time I'm on a hill I'll just focus on positioning the clutch and see how long I'm held.

 

I've been very happy with it, in my MT 2.7.

 

3.5 auto. my truck does not have it. My last car did, so I know what I'm looking for. Truck doesn't have it or it is not functioning.

Is it an option or included in a package?

I think it may only be on the manuals...

 

I dont know of any Manual transmission that can place the shift lever into "P" location in the gearbox....


see the excerpt from the manual for the truck:

 

http://www.toyota.com/tacoma/ebrochure/ lists "• Hill Start Assist Control (HAC)30 (A/T only)" for every trim level.

http://www.toyota.com/tacoma/features/safety_convenience/7594/7544/7582/7598 says:
"Hill Start Assist Control is designed to help minimize backward rolling on steep ascents. It is not a substitute for safe driving judgment and practices. Factors including grade, surface conditions and driver input can all affect whether HAC will be effective in preventing a loss of control. "

http://www.toyota.com/tacoma/ says:
"
Hill Start Assist Control
Tacoma’s Hill Start Assist Control (HAC) 18 helps you safely get up those hills. This technology helps minimize Tacoma from rolling backward when you move your foot from the brake to the gas pedal, so you can move upward with confidence. (HAC not available on TRD Off-Road 4WD M/T.)
"

 

It holds the truck after you release the brake pedal, for a short 2 seconds, until you apply gas/brake inputs. End of story.

 

If only it did.... for me and many others our trucks roll back and make a funny noise and an indicator light on the dash flashes while it rolls back (instead of the truck being held firmly in place).

 

Thats what it is SUPPOSED to do...

My truck doesn't have it!

 

Then it's not working. Take it do the dealer to get fixed.

 

Next we need to figure out if it is correlated with build dates or factories

 

some already did (in one of the other posts i linked) and the dealer "tested" another Tacoma on the lot and it behaved the same way so they said it was working as intended. Obviously it isn't!

See here: https://www.tacomaworld.com/threads/hill-start-assist.399682/page-2#post-11114971

 

My truck is an Automatic and was built in Baja Mexico, it rolls back instead of holding firm.

 

Wait wait wait.... 5 votes saying MT doesn't roll back and I'm the only one saying it does? Mine might be broken then ha. Mine has *never* held itself. I was under the impression the MTs did not come with this feature.

EDIT: Upon further inspection my thoughts seem to be in line with Toyota documentation... it states in multiple places HAC is AT only and furthermore it explicitly says HAC not available on TRD OR 4WD MT which is exactly what I have...

 

Hill Start Assist (A/T Only), Doesn't A/T mean Automatic Transmission? Mine is a manual and it does not have it.

 

Yup - works as claimed. I don't live in a particularly hilly area so it doesn't wow me, but I could see it really helping out where there are lots of traffic lights and really steep hills - somewhere like SF.

 

I see...it must not be on any trucks with atrac or MTS!

 

Then the other Taco is similarly defective, and that dealer is clueless (shocking) or giving the run-around to get out of doing warranty work (equally shocking).

This is my third vehicle with this feature and they all behaved exactly the same. All three are different brands and different types of vehicles ('07 BMW 335i 6MT coupe, '06 MB ML350 7AT SUV, '16 Taco) - the behaviour is standard and consistent across all.

// edit - To those that have the rolling back / loud noise / flashing on dash issue: do you all own Off-Road models? One theory I have is that Toyota might have cut corners and used some part of the crawl control (which makes noise) to add this (limited) functionality on the OR models, whereas Sport models got the proper unit? A total shot-in-the-dark guess on my part.