QP EPB/ABS/MSP/ASR/Suspension Warning lights - unlikely to be voltage issue

A

adwoot

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So a bit of a long-winded issue... Had the full set of above fault lights appear a couple of times recently, seemed to be when the EPB was coming on when switching the ignition off. Assumed to be random gremlins as they cleared on ignition until a bigger problem today.

After being parked up for a couple of hours, I started up as normal but the EPB wouldn't release, neither on the light nor physically. Then the above warning lights came on inc EPB failure. Tried a few more times and I could feel a pulse in the brake pedal but no luck with the EPB. Waited a few minutes, tried again and the EPB released but I noticed the pedal felt very hard. Moved off and the ABS/ASR/Suspension failure warnings came on again and the pedal softened back to normal. As miles from home, did short journey, parked for a couple of hours with EPB off but exactly the same happened with the pedal hardness on ignition again with failure warnings, which won't clear for more than a few seconds on ignition.

Now home, I've tried a few more scenarios. EPB is now working normally without warnings but the ABS etc warnings are coming on immediately, and the pedal is hard until after a couple of seconds pressure.

Brakes feel normal while driving, but something is really amiss. It's unlikely to be voltage related as the battery is quite new and always trickle charged showing good health. Car is a 2008 early ZF with Skyhook.

Interested in thoughts of what could be wrong, and whether I need to sell a few organs to get it sorted. I'm around 130 miles from my nearest specialist so can't just pop over, so although it might not be fixable by DIY it'll be helpful for some ideas. If it is not a sensor hissy fit then I'm wondering if it is the ABS pump? I've disconnected the battery for now to see if I get a reset but with the brake pedal symptom I suspect it could be mechanical. Thanks for any pointers of experience with similar issues.
 
conaero

conaero

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I would say that has all the markers of a failed abs wheel sensor, unfortunately it’s inside the wheel bearing so the whole unit at about £500 plus fitting. Needs proper diagnosis to confirm.
 
Silvercat

Silvercat

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1,166
Likewise ABS sensor. On my old 2009 QP it cost £620+vat for a new hub unit containing the sensor and a couple of hours to fit. So count on about £1k if you take it to a MD or inde. But if it ends up being the main ABS control unit, then looking at over £2k.
 
A

adwoot

New Member
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Thanks all for your warm words of reassurance :0036:

Good news is that after an overnight battery disconnect and full charge, it's now a permanent fault, which is always preferable to an intermittent fault.

I've now read the other linked thread, and two points which are not quite conclusive:
  • yesterday's EPB hissy fit. Coincidence or some sort of related issue?
  • the pedal going rock hard (at the top of travel) on ignition but then going back to normal after a couple of presses. That's a new "feature". Is the brake system over-pressurising?

I'll get it booked in somewhere when I can, fortunately I've a runabout I can use though curiously that has also developed intermittent brake issues recently. And that's not Italian!
 
rs48635

rs48635

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3,181
CAVEAT "must be diagnosed first" - which means plugging the car into proper diagnostic machine.

Had two of these units replaced on my 2006 QPV and would happily DIY or give to local mechanic next time. One was failed ABS the other bad bearing noise. Can't even make one good from two failed units as only one came back.
 
A

adwoot

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So a minor update... I'm trying to "self-help" as I am a long way from a specialist, so I'm probably about a month away from being able to get the car looked at properly with a diagnostics machine. It needs other jobs doing anyway so the trip will happen regardless of whether I fix this issue.

I've spent a bit more time trying to see if there is a pattern to the faults, to rule in/out silly stuff. The faults are sometimes clearing on startup, but the most I get is around 30 seconds (stationary) before the disco starts.
  • Have noticed the "Park Off" for the EPB is permanently active and the button does not do anything, except for one random moment when it decided to behave. The handbook says this is normal if it detects low voltage.
  • The EPB is warning of a failure about 50% of the time, but works properly the rest. Except the first time it locked on last week, and again at the weekend, I had my phone on charge via the cigarette lighter, unplugging the phone helped it to release. Coincidence or possible voltage?
  • On the EPB theme, the two times it has locked on I can actually feel movement in the brake pedal and hear a clunk from the boot when trying to release. As I am sure these cars have drum/shoes for the handbrake (correct me if I'm wrong) then I am puzzled why I can feel it trying to release through the brake pedal.
  • Warning lights - still consistently the ABS/ASR/MSP/Suspension, also accompanied by an EBD failure for a short while. Do I get a prize for all the lights?

Bearing in mind, the initial incident with the ABS etc was when I encountered the first EPB failure, could this still be an ABS sensor? I don't see the ABS being out as a cause for the EPB issues hence why I am not completely convinced.

So voltage maybe... It's an 18 month old Excell 95A battery and all that time gets trickle charged when parked up for more than a couple of days. Exception was prior to this latest round of issues where it was parked on street for about 10 days without charge, though the faults manifested a bit later on. Checked the resting voltage this evening and it is 12.2V, and had a similar reading at the weekend after it had been on an hour run, so not much opportunity to discharge. Running voltage is around 14.5V so all seems fine then.

I know 12.2V is on the low side and could certainly explain the EPB issue. And I sometimes get 30 seconds of no faults on startup. So are these symptoms pointing more towards battery than sensors/ABS controller? I'm tempted to get a new battery on a sale-or-return basis, (are Eurocarparts reasonable with returns?) but not if it is going to be a certain waste of time and effort.

Further thoughts welcome please :)
 
philw696

philw696

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25,377
Make sure you haven't got water in the bottom of the boot and that the EPB has not suffered ingress.
 
spkennyuk

spkennyuk

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5,950
adwoot said:
So a minor update... I'm trying to "self-help" as I am a long way from a specialist, so I'm probably about a month away from being able to get the car looked at properly with a diagnostics machine. It needs other jobs doing anyway so the trip will happen regardless of whether I fix this issue.

I've spent a bit more time trying to see if there is a pattern to the faults, to rule in/out silly stuff. The faults are sometimes clearing on startup, but the most I get is around 30 seconds (stationary) before the disco starts.
  • Have noticed the "Park Off" for the EPB is permanently active and the button does not do anything, except for one random moment when it decided to behave. The handbook says this is normal if it detects low voltage.
  • The EPB is warning of a failure about 50% of the time, but works properly the rest. Except the first time it locked on last week, and again at the weekend, I had my phone on charge via the cigarette lighter, unplugging the phone helped it to release. Coincidence or possible voltage?
  • On the EPB theme, the two times it has locked on I can actually feel movement in the brake pedal and hear a clunk from the boot when trying to release. As I am sure these cars have drum/shoes for the handbrake (correct me if I'm wrong) then I am puzzled why I can feel it trying to release through the brake pedal.
  • Warning lights - still consistently the ABS/ASR/MSP/Suspension, also accompanied by an EBD failure for a short while. Do I get a prize for all the lights?
Bearing in mind, the initial incident with the ABS etc was when I encountered the first EPB failure, could this still be an ABS sensor? I don't see the ABS being out as a cause for the EPB issues hence why I am not completely convinced.

So voltage maybe... It's an 18 month old Excell 95A battery and all that time gets trickle charged when parked up for more than a couple of days. Exception was prior to this latest round of issues where it was parked on street for about 10 days without charge, though the faults manifested a bit later on. Checked the resting voltage this evening and it is 12.2V, and had a similar reading at the weekend after it had been on an hour run, so not much opportunity to discharge. Running voltage is around 14.5V so all seems fine then.

I know 12.2V is on the low side and could certainly explain the EPB issue. And I sometimes get 30 seconds of no faults on startup. So are these symptoms pointing more towards battery than sensors/ABS controller? I'm tempted to get a new battery on a sale-or-return basis, (are Eurocarparts reasonable with returns?) but not if it is going to be a certain waste of time and effort.

Further thoughts welcome please :)
Click to expand...

The EPB uses the abs sensor in the hubs as one of it signal inputs. So if the bearing has slight play in it the abs sensor throws out a reading out of sync with the other wheels. If the system gets a continious different reading from one sensor then you get the fault light for abs/msr. You will also loose hill hold and epb. Hill hold being another application of epb in cars even though you may have a manual handbrake like on the 4200/GS.

If your still getting the fault on a known good battery then your looking at one of the hubs/abs sensor being at fault.
 
eight

eight

Junior Member
Messages
94
Rather than start a new thread may I quickly ask - EPB - it takes a couple of seconds of flashing of the indicator light before it goes out. I've been waiting until it's extinguished before I move the car.
When it's still flashing is it safe to move or better to wait? Don't want to break anything!
 
Ryandoc

Ryandoc

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1,842
I have this exact fault at the moment. Battery not that old and in good health by all accounts.

Im booked in at my local indi on the 30th so will report back
 
Zep

Zep

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9,230
eight said:
Rather than start a new thread may I quickly ask - EPB - it takes a couple of seconds of flashing of the indicator light before it goes out. I've been waiting until it's extinguished before I move the car.
When it's still flashing is it safe to move or better to wait? Don't want to break anything!
Click to expand...

The brake is applied by a motor, I believe the light flashes until the motor has completed its full stroke to the open position, although in practice it has released pretty much instantly. I would keep doing what you are doing to be honest.
 
CatmanV2

CatmanV2

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48,734
Zep said:
The brake is applied by a motor, I believe the light flashes until the motor has completed its full stroke to the open position, although in practice it has released pretty much instantly. I would keep doing what you are doing to be honest.
Click to expand...

It automatically releases anyway. As @Zep says, it's pretty much instant, otherwise you couldn't drive it away in the 'automatic' mode.

C
 
spkennyuk

spkennyuk

Member
Messages
5,950
CatmanV2 said:
Does it? Why? Curious is all

C
Click to expand...

Yes most systems have at least 2 input. One being the abs sensor the other being the switch or pedal press that engages the epb or hill hold facility. Depending on the exact system there can be further inputs for voltage at the motor for example.

It reads the abs sensor because if the system detects movement at the wheel then it knows the EPB has not applied fully for whatever reason either motor fault or system pressure for example.
 
CatmanV2

CatmanV2

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Hmm, my ZF GT I am totally sure didn't use the EPB. The hold function was due to the drag on the torque converter. You could hear the EPB working when it did.

Obvs the 4200CC didn't have an EPB, but again used clutch drag for hill hold. Seems odd to overcomplicate things for the F1....

C
 
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