Almost 6 years later, how did I not notice this before?

[GSMacLean]

Come this June, I will have had my 2013 Energi for 6 years.

 

Last night I noticed that it does something, that I've never noticed before. I'm fairly sure it's intentional (i.e. programmed). I tested it quite a few times, and was able to duplicate the behavior. Here's what it is:

 

When on a hill (with the nose of the car facing up the hill), come to a full stop. Hold the brakes on. Now, let off the brakes - note that the brake lights stay on by themselves for about 1.5 seconds before turning off.

 

However...if you touch the accelerator during that 1.5 seconds, they turn off instantly.

 

The car does NOT do this if it is on level ground, or facing downwards.

 

I suspect it is to prevent people behind you from starting to drive forward before you actually start to accelerate?

 

[Bill-N]

It's a hill-holder of sorts.  It keeps the car from rolling backward after the brakes are released but before the car is moving forward.  My '53 Studebaker had one but without the 1.5 second release.

 

 

Cheers.

[GSMacLean]

I've had Subarus with this feature, they had a one-way valve that would hold brake pressure on when you released the brake on a hill, until you pressed the accelerator (or was it when you released the clutch? I don't recall).

[djc]

On Subarus it requires a small device mounted on the fender with a brake line running through it; I read that Subaru copied it from Studebaker.  On the C-max, I think one of the electric motors is holding the car in place, not the actual brakes, and it just requires some lines of code...

[plus 3 golfer]

On Subarus it requires a small device mounted on the fender with a brake line running through it; I read that Subaru copied it from Studebaker.  On the C-max, I think one of the electric motors is holding the car in place, not the actual brakes, and it just requires some lines of code...

 

Hill Start uses the brakes as described in the Service Manual.  Every car I've owned for quite some time has had this feature.  The ABS uses the stability sensor messages from the Restraints Contol Module. When the ABS determines the vehicle is on about a 3% grade or more, it enables the Hill Start function.  If the ABS determines there is insufficient torque once the brake is released and the accelerator pedal is pressed to move the vehicle, it will continue to hold the vehicle in place beyond the normal hold time. The Hill Start function works in both forward (D) or reverse ® if backing up a hill.

 

From the Owner's Manual:

 

The system makes it easier to pull away

when your vehicle is on a slope without the

need to use the parking brake.

When the system is active, your vehicle will

remain stationary on the slope for two to

three seconds after you release the brake

pedal. This allows you time to move your

foot from the brake to the accelerator

pedal. The brakes are released

automatically once the engine has

developed sufficient drive to prevent your

vehicle from rolling down the slope. This

is an advantage when pulling away on a

slope, (for example from a car park ramp,

traffic lights or when reversing uphill into

a parking space).

The system will activate automatically on

any slope that will cause significant vehicle

rollback.

Using Hill Start Assist

1. Press the brake pedal to bring your

vehicle to a complete standstill. Keep

the brake pedal pressed.

2. If the sensors detect that your vehicle

is on a slope, the system will activate

automatically.

3. When you remove your foot from the

brake pedal, your vehicle will remain

on the slope without rolling away for

about two or three seconds. This hold

time will automatically be extended if

you are in the process of driving off.

4. Drive off in the normal manner. The

brakes will release automatically.

[joshg678]

It also works in reverse with nose pointing down!

[MNizlek]

We have a 2013 Hybrid SE.  Similar to GSMacLean, earlier, Hill Start Assist on our vehicle has recently started acting up.  (Grade Assist has been an issue as well.  More on that below).  We live on a hillside.  To exit our drive, there is a short level section as we back from the garage.  As you back, you turn to aim up the drive.  Inconsistently, after you apply the brakes and shift to Drive (or Low), on accelerating the car bucks and jerks.  This same condition will occur in traffic when stopped on a grade.  (This is of major concern, since the car starts forward, then suddenly jerks to a stop and drivers behind us have nearly plowed into us.)  Timing seems to be a factor.  If you wait more than about 2 seconds between removing your foot from the brake pedal and pressing the accelerator, chances are higher it will occur.  Subsequently an unusual sound will occur following the jerking; like the tranny is in some other gear, but that's speculation on my part.  If you have any information on cause and resolution of this, please advise.

 

The (down) grade assist feature, since early in our ownership, has had an issue as well.  If activated for a down grade, then turned off nearing the bottom of the hill, one needs to pump the brakes before braking to a stop.  If you don't do this, and apply the brakes to reach a full stop, the car will jerk twice as it stops.  These are not nearly the magnitude as the Hill Assist issues, above, but are a concern.  We have stopped using this feature, but would like it, if repaired.

[plus 3 golfer]

Perhaps ABS is acting up / being triggered by a faulty device.  Has there been any work done on car just prior to this issue?  Describe the sound after the jerking. Is it a whooshing sound, metallic sound.  Can you record it?  When using grade assist, do you have the issue every time? or does the HVB have to be virtually full? as using brakes with full HVB requires the mechanical brakes as there is no room in the HVB for regeneration braking.

 

There is an electric vacuum pump that will likely start up when vacuum is low (that might be the sound).  Perhaps there's a vacuum leak as in the hill hold uses the mechanical brakes (brake pedal pushed in) and when disengaging grade assist and having to pump brake pedal indicates that mechanical brake booster system may not be working correctly.  ABS should sense this and perhaps operates the brakes electrically hence the jerking until vacuum is built back up.

[fbov]

See if you had the RCM replaced, under recall 14S04. Mine died in 2014 when I hit a pothole, and the dash went Christmas Tree, so I got moved up on the retrofit list. You may have been missed. Just a thought. 

Frank

[plus 3 golfer]

Yes, a faulty RCM could be providing bad pitch data to the ABS. 14S04 was to reprogram the RCM supposedly so that side airbags would not delay in deployment.

 

Recall 14S21 RCM replacement, issued several months after 14S04, if not done, may be the issue.

“ The coating on portions of the Restraint Control Module (RCM) may crack, and when exposed to humidity, circuits on the printed circuit board may short.

 

Consequence

The short circuits could cause the frontal air bags, side curtain air bags and the seat belt pretensioners to not function as intended when needed, increasing the risk of occupant injury in the event of a crash.”

Edited July 21, 2019 by Plus 3 Golfer

[MNizlek]

All - thanks for the replies.

 

PLUS3 - "Was there work just prior to issue". No.   "What sound does it make?"  Whooshing.   "Everytime?" Event does not occur each time and neither does whooshing sound."

 

fbor - Recall/reprogramming - Some module updates have been done, but to be honest, I have not been diligent in tracking these and my service reports are not explicit.  Is this information accessible anywhere/should the dealer have this information on record?  Ford?

[plus 3 golfer]

First, go to owner.ford.com where you can check for recalls.  Also, on etis.ford.com you can enter your VIN and see all Outstanding Field Service Actions.

 

A whooshing sound is likely air rushing into the brake booster which is normal when pushing the pedal in as a valve opens to allow outside air to enter one side of the brake booster. The other side is under vacuum which assists in the movement of the push rod to make pushing the brake pedal easier.  Although most will never hear the sound under normal operation. The sound could also indicate a large vacuum leak.  

 

The next thing to do is likely scan the control modules for Diagnostic Trouble Codes, especially immediately after the event.  Problem is dealer will likely charge $100+ just to do it.  So, you want to make sure you can duplicate the event for the SA and maybe even tech.   Since it appears to be ABS related, the dealer may also want to run the brake calibration procedures especially if no DTCs to ensure the ABS knows the "zero" position of the roll, yaw, and pitch sensors.

 

If you are into "trouble shooting", you can get the ForScan App for a smartphone and a $20 or less OBDII ELM327 adapter to plug into the OBDII port and scan / troubleshoot yourself.

Edited July 21, 2019 by Plus 3 Golfer

[MNizlek]

Plus 3 - I've found  etis.ford.com reluctant to accept my attempts to register, then review my VIN info.  Can one register as an independent entity?  (I've left an email for them, but no reply yet.)  Thanks.  MN

[plus 3 golfer]

Prior you could enter vin under vehicle tab and get data. No need to register. Apparently changed now. Owner.ford you can register and get open recalls and FSAs.

[MNizlek]

So as not to leave this issue/topic without closure, here is a status/update.  We left our car with our Ford dealer service department for several days to see if they could (a) replicate the issue, or (b) inspect for faults and mechanical issues.  They were not successful in either replicating the issue or finding mechanical issues.  In the several days since we're had the vehicle back, the issue continues in a random fashion as described in my 7/20 post.  

 

Would it be a good idea to create a new post on this issue?

 

Also, what is your opinion of the "On line Mechanic" advertised on these forum pages?