X7 Electric handbrake

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Trainman
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Re: X7 Electric handbrake

Post by Trainman » 18 Jun 2019, 17:03

Right then, I've run Lexia over the Secondary Electric Brake ECU, originally there were 4 faults listed:

C1554 - Temporary fault, Electric motor temperature sensor Coherence
P0562 - Temporary fault, ECU low supply voltage
C1550 - Temporary fault, Brake cable
C1559 - Temporary fault, Electric motor control

so I cleared those fault, which all cleared and then tried to reset the handbrake, at which point I got these faults

C155E - Temporary fault, Mechanical unlocking of the electric parking brake detected
U1108 - No communication with engine EC U no signal
U1313 - Permanent fault, No communication with electronic stability program (ESP) ecu
C1559 - Temporary fault, Electric motor control

once again I cleared the faults and they have all disappeared, but I still get the flashing red circle!

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GiveMeABreak
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Re: X7 Electric handbrake

Post by GiveMeABreak » 18 Jun 2019, 17:25

Ok, I'll have a squiz now...

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GiveMeABreak
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Re: X7 Electric handbrake

Post by GiveMeABreak » 18 Jun 2019, 18:03

So P0562 would explain a lack of communication with the ECU. The ECU needs a minimum of 8.1V to operate. Now I can tell you that I had a similar issue with the parking brake not releasing after I had the car parked up for a few weeks and the battery was in a weakened condition. I took the battery off and charged it overnight, and then after 2 attempts at releasing the handbrake it worked. It did take a while - so seemed to be doing some sort of calibration. So I applied it a couple of times and all is well again.

The thermal code (C1554) I can understand if you have been continually operating and attempting to release it - that would make sense.

As for U1313, that relates to a fault in the reception of the partial triggering message by the built-in systems interface - but agrees with the same conclusion as the C1559 fault as being the unit itself (unless you had any reason to suspect the ESP ECU).
Fault CodeU1313
After sales description of the fault codeFault in the reception of the partial triggering message by the built-in systems interface (BSI)
Description of the diagnosticsThe dynamic stability control ECU causes functional faults
Conditions of activation of the diagnosticsIgnition on
Conditions of disappearance of the faultReception of 3 consecutive items of valid information
Down-grade modes if fault presentDeactivation of automatic mode
Ignition on: The electrically controlled parking brake releases if the button is not held
Ignition off: The electrically controlled parking brake releases if you hold the button for less than 3 seconds
Switching on of the warning lamp and/or warning messageWarning lamp
- "a": lit
- "b": lit
- "c": lit
Main customer complaints likelySwitching on of the warning lamp and/or warning message
Electrically-controlled parking brake does not apply correctly
Electrically-controlled parking brake releases unexpectedly
Electrically-controlled parking brake does not release correctly
Electrically-controlled parking brake applies itself unexpectedly
The hill start assist is not working
Loss of stability of the vehicle in dynamic braking
Suspect areasElectronic stability control (ESP)
Electric parking brake

However the remaining issue of C1559 could be the unit itself and may need replacing. What exactly the 2000 'Maximum number of releases at the Stop' relates to exactly, I can't say, but that can't relate to the max. number of applications as that would be over in 250 days at 4 application and release cycles a (8 operations per day).

Ok, so here is the common fault - and below the table are the symbols / warning lights that 'a, b & c' refer to.
Fault CodeC1559
After sales description of the fault codeSystem locked: Electric motor, cables or callipers
Description of the diagnosticsThreshold of the application and release counter exceeded
Rotation speed of the electric motor too high
Lockup detected
Maximum number (=2000) of releases at the stop exceeded
Conditions of activation of the diagnosticsActivation of the electrically-controlled parking brake
Conditions of disappearance of the faultApplication and release of the electrically-controlled parking brake successful
Down-grade modes if fault presentDeactivation of automatic mode
No application or release
Switching on of the warning lamp and/or warning messageWarning lamp
- "a": lit
- "b": On for 10 seconds after the request for application or release
- "c": lit
Main customer complaints likelyIllumination of LED/Error message
Electrically-controlled parking brake does not apply correctly
Electrically-controlled parking brake releases unexpectedly
Suspect areasElectric parking brake
Attachments
Steve Parking Brake A.PNG

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Re: X7 Electric handbrake

Post by Trainman » 18 Jun 2019, 18:27

So basically, looking at the above, it sounds like the electronic handbrake is knackered.........

I get it up on ramps tomorrow and see if I can see if anything

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Re: X7 Electric handbrake

Post by Y Cymro » 21 Aug 2019, 21:53

Hi Steve
Did you get anywhere with this? Mines got a snapped cable and I’m not looking forward to spending over a grand on a new unit.

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Re: X7 Electric handbrake

Post by Trainman » 23 Aug 2019, 11:36

To be perfectly honest, I've decided to bite the bullet and buy a new one........ not ideal.....but......

when the old one is off, im going to strip it down and see what's what.......