Lost brake while driving; scary, concerning.

[Edgingage]

Hi folks, 2011 Edge SEL here (205,000 km; ~127,000 miles)

 

I just had a very scary event this morning: while driving in the city (TG), approaching the lights my brake pedal went to the floor with no much brake action other than deacceleration.  As I was very close to home (just a handful of Kms) I kept going very slowly (with my emergency lights on), and once in a while I was "testing" (pushing) the brake pedal with the same result: very little resistance to stop the vehicle. 

 

I managed to get home without an accident. Once in my parking lot, I drove the vehicle back and forth (slowly) with the same result: brake pedal to the metal and no real break action, very little, if any.  I shut it off and called the dealer to explain the situation: they told me you could probably not drive the car here, I said yes, it's just a couple of Km away.  I drove it to the dealer; however, in my way to the dealer the brakes were working properly, I tried to do the same thing (pressing the brake pedal at different intervals, speeds and pressure) and the brakes always worked as normal.

 

Hum, I told the dealer, now I have to problems: what about if you guys can reproduce the failure I had before.  And of course, I'm not confident to drive the car without finding out what went wrong.

 

As a background info, the brake booster was replace about three years ago.  At the time what happened was the other way around: I had to literally step on the brake pedal to put enough pressure to stop the car even while driving slowly.  This time there was no resistance from the pedal.

 

So, my questions to you folks:

- anybody with a similar experience?

- if the brake booster was replaced three years ago, could it be gone so soon again?

- where should be the first place/part to look at it?  This question is very important as the dealer didn't know where to start looking and I'm afraid they my charge me $200 just for looking (and not finding the problem).

 

And yes, I did check for break fluid leak and level: no fluid leaks; all fluid levels OK.

 

I'm lost; don't know where to look or what else to do.  Please help.

 

Thank you folks.

 

Chris.

Edited August 2, 2022 by Edgingage

[Haz]

No similar experience apart from your description of failed brake booster symptoms in our 2012 MKX, which was replaced under the 13N02 warranty extension.

 

To provide you a starting point, the following is a partial symptom list edited to include your Edge's brake system behavior,  from the 2011 Edge Workshop Manual...

 

ion procedures don't

 

In addition, below as PDF download links are relevant sections from the Workshop Manual that provide the same inspection and evaluation guidance that a dealership technician would employ toward a potential $200 review of your Edge's brake system.

 

Many of the evaluation steps involve inspection & performance observation and do not initially require disassembly of components, though component removal procedures are also included...

 

Brake System Symptom Chart - Brake System Diagnosis and Testing - 2011 Edge Workshop Manual.pdf

Brake System Inspection - Brake System General Procedures - 2011 Edge Workshop Manual.pdf

Brake System Component Tests - Brake System Diagnosis and Testing - 2011 Edge Workshop Manual.pdf

Power Brake Booster - Removal and Installation - 2011 Edge Workshop Manual.pdf

Brake Master Cylinder - Removal and Installation - 2011 Edge Workshop Manual.pdf

Brake Pedal and Bracket - Removal and Installation - 2011 Edge Workshop Manual.pdf

Stoplamp Switch - Removal and Installation - 2011 Edge Workshop Manual.pdf

 

If your efforts reveal a questionable condition that you prefer not to address yourself, at least you'll be able to speak with your dealer about what you looked at and found, perhaps allowing their diagnosis to occur more quickly and less expensively.

 

Good luck!

 

[Edgingage]

4 hours ago, Haz said:

No similar experience apart from your description of failed brake booster symptoms in our 2012 MKX, which was replaced under the 13N02 warranty extension.

 

Good luck!

 

Haz, wow!, BIG thank you for all the detailed info you have provided above.

 

Lots of things and steps to check and go through.  I'm in big trouble.  Let's see how we can navigate through those things.

 

The worse part is that, whatever problem I had is an intermittent problem; and that's a huge problem because: 1) I haven't been able to reproduce it again; 2) if the shop can't reproduce the problem how can I make sure whatever they've done actually solved the problem? (if you know what I mean).  Unless a specific problem is found, even if I do all the checks and balances (i.e., if I do most of the things listed above), I won't be 100% certain that the problem won't reoccur in the middle of the highway next time, unless the culprit is found & fixed.  Sad days are coming for my Edge (or myself ;))

 

Thank you Haz; thanks again.

Edited August 2, 2022 by 1004ron
No need to quote everyting

[WWWPerfA_ZN0W]

if you heard a squeaking/whistling/whooshing sound when stepping on the brakes, it is the booster.

 

if not, you may have a faulty ABS module. 

 

the master cylinder hardly ever fails on this platform.

[Haz]

If you can scan your Edge -- or have it scanned at a local auto parts store (sometimes at no cost), these brake-related Diagnostic Trouble Codes (DTCs) may indicate ABS module failure and/or HCU failure requiring component replacement(s)...

 

DTC Charts

NOTE: This module utilizes a 5-character DTC followed by a 2-character failure type code. The failure type code provides information about specific fault conditions such as opens or shorts to ground. Continuous Memory Diagnostic Trouble Codes (CMDTCs) have an additional 2-character DTC status code suffix to assist in determining DTC history.

  ABS Module DTC Chart

 

DTC	Description	Action
C0001:49	TCS Control Channel "A" Valve 1: Internal Electronic Failure	This DTC indicates that part of the ABS module has failed internally. CLEAR the DTCs. REPEAT the self-test. If DTC C0001:49 returns: For vehicles without adaptive cruise control, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. TEST the system for normal operation. For vehicles with adaptive cruise control, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section. TEST the system for normal operation.
C0002:49	TCS Control Channel "A" Valve 2: Internal Electronic Failure	This DTC indicates that part of the ABS module has failed internally. CLEAR the DTCs. REPEAT the self-test. If DTC C0002:49 returns: For vehicles without adaptive cruise control, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. TEST the system for normal operation. For vehicles with adaptive cruise control, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section. TEST the system for normal operation.
C0003:49	TCS Control Channel "B" Valve 1: Internal Electronic Failure	This DTC indicates that part of the ABS module has failed internally. CLEAR the DTCs. REPEAT the self-test. If DTC C0003:49 returns: For vehicles without adaptive cruise control, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. TEST the system for normal operation. For vehicles with adaptive cruise control, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section. TEST the system for normal operation.
C0004:49	TCS Control Channel "B" Valve 2: Internal Electronic Failure	This DTC indicates that part of the ABS module has failed internally. CLEAR the DTCs. REPEAT the self-test. If DTC C0004:49 returns: For vehicles without adaptive cruise control, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. TEST the system for normal operation. For vehicles with adaptive cruise control, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section. TEST the system for normal operation.
C0010:49	Left Front Inlet Control: Internal Electronic Failure	This DTC indicates that part of the ABS module has failed internally. CLEAR the DTCs. REPEAT the self-test. If DTC C0010:49 returns: For vehicles without adaptive cruise control, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. TEST the system for normal operation. For vehicles with adaptive cruise control, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section. TEST the system for normal operation.
C0011:49	Left Front Outlet Control: Internal Electronic Failure	This DTC indicates that part of the ABS module has failed internally. CLEAR the DTCs. REPEAT the self-test. If DTC C0011:49 returns: For vehicles without adaptive cruise control, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. TEST the system for normal operation. For vehicles with adaptive cruise control, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section. TEST the system for normal operation.
C0014:49	Right Front Inlet Control: Internal Electronic Failure	This DTC indicates that part of the ABS module has failed internally. CLEAR the DTCs. REPEAT the self-test. If DTC C0014:49 returns: For vehicles without adaptive cruise control, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. TEST the system for normal operation. For vehicles with adaptive cruise control, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section. TEST the system for normal operation.
C0015:49	Right Front Outlet Control: Internal Electronic Failure	This DTC indicates that part of the ABS module has failed internally. CLEAR the DTCs. REPEAT the self-test. If DTC C0015:49 returns: For vehicles without adaptive cruise control, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. TEST the system for normal operation. For vehicles with adaptive cruise control, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section. TEST the system for normal operation.
C0018:49	Left Rear Inlet Control: Internal Electronic Failure	This DTC indicates that part of the ABS module has failed internally. CLEAR the DTCs. REPEAT the self-test. If DTC C0018:49 returns: For vehicles without adaptive cruise control, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. TEST the system for normal operation. For vehicles with adaptive cruise control, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section. TEST the system for normal operation.
C0019:49	Left Rear Outlet Control: Internal Electronic Failure	This DTC indicates that part of the ABS module has failed internally. CLEAR the DTCs. REPEAT the self-test. If DTC C0001:49 returns: For vehicles without adaptive cruise control, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. TEST the system for normal operation. For vehicles with adaptive cruise control, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section. TEST the system for normal operation.
C001C:49	Right Rear Inlet Control: Internal Electronic Failure	This DTC indicates that part of the ABS module has failed internally. CLEAR the DTCs. REPEAT the self-test. If DTC C001C:49 returns: For vehicles without adaptive cruise control, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. TEST the system for normal operation. For vehicles with adaptive cruise control, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section. TEST the system for normal operation.
C001D:49	Right Rear Outlet Control: Internal Electronic Failure	This DTC indicates that part of the ABS module has failed internally. CLEAR the DTCs. REPEAT the self-test. If DTC C001D:49 returns: For vehicles without adaptive cruise control, INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. TEST the system for normal operation. For vehicles with adaptive cruise control, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section. TEST the system for normal operation.
C0020:11	ABS Pump Motor Control: Circuit Short To Ground	This DTC indicates that part of the HCU has failed internally. CLEAR the DTCs. TEST DRIVE the vehicle. REPEAT the self-test. If C0020:11 returns, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section. TEST the system for normal operation.
C0020:12	ABS Pump Motor Control: Circuit Short To Battery	This DTC indicates that part of the HCU has failed internally. CLEAR the DTCs. TEST DRIVE the vehicle. REPEAT the self-test. If C0020:12 returns, INSTALL a new HCU . REFER to Hydraulic Control Unit (HCU) in this section.

 

Additional Workshop Manual resources on ABS Module and HCU as PDF download links...

 

Anti-Lock Brake System (ABS) Description and Anti-Lock Control Operation - 2011 Edge Workshop Manual.pdf

Anti-Lock Brake System (ABS) and Anti-Lock Control Diagnosis and Testing - 2011 Edge Workshop Manual.pdf

Anti-Lock Brake System (ABS) Module Location Illustration - 2011 Edge Workshop Manual.pdf

Anti-Lock Brake System (ABS) Module - Removal and Installation - 2011 Edge Workshop Manual.pdf

Hydraulic Control Unit (HCU) - Removal and Installation - 2011 Edge Workshop Manual.pdf

Anti-Lock Brake System (ABS) Module Wiring Connector C135 Details - 2011 Edge Workshop Manual.pdf

 

The failure of the brake booster in our 2012 MKX initially exhibited normal boost-assist, but with a somewhat lower pedal height for about three weeks without any audible symptom. The catastrophic failure happened at  stop sign, where the pedal went all the way to the floor, with braking only occurring with very high stand-on-it effort level, and a noticeable hissing noise when the pedal was at floor level. At no time did normal braking behavior reappear, until after the brake booster was replaced. Driving it to the dealership, there was no boost or progression to braking -- just high effort and harsh braking at floor level.

 

Good luck!