Brake boost vacuum pump ECU fault. - Renault Z.E. Forum
Reply
 
LinkBack Thread Tools
post #1 of 16 (permalink) Old 07-26-2013, 03:54 PM Thread Starter
Senior Member
 
Join Date: Jul 2013
Posts: 803
Brake boost vacuum pump ECU fault.

Renault have notified dealers to check a brake vacuum pump control ECU on Fluence ZE (possibly affecting other ZE models). These are to be checked and replaced where necessary at the next service if they do not correspond with serial no 472503090R.

Turns out mine is one affected, and that the dealer missed this when doing the pre delivery checks.

Just as well I called to find out about this, this morning.

The service manager seemed genuinely apologetic that they had missed this. I checked the number myself, rather than wait for a tech to turn up (it involves loosening a clamp nut to the ECU and examining the SN). He'll sort out what to do next with Renault, and, hopefully, will send a tech over to me to replace the ECU.
donald is offline  
Sponsored Links
Advertisement
 
post #2 of 16 (permalink) Old 07-26-2013, 08:56 PM
Banned
 
Join Date: Jul 2013
Posts: 381
RE: Brake boost vacuum pump ECU fault.

Why is it not a recall? You can't get any more serious than brake failure.

Got a 3 year old new shape Prius and that has just been recalled for replacement of the vacuum pump due to failure of a handful of units in America. According to my dealer it is an expensive part and takes about 3 hours to replace. I'm fine with it as my car has 80k miles on it and will be getting a big new part, but the question remains is why Renault aren't recalling their cars for a similar issue and it appears to have affected a higher percentage of vehicles.
GrumpyCabbie is offline  
post #3 of 16 (permalink) Old 07-27-2013, 03:54 AM Thread Starter
Senior Member
 
Join Date: Jul 2013
Posts: 803
RE: Brake boost vacuum pump ECU fault.

My guess (Paul has the experience - mind - so it's his call) is that his was actually a brake boost failure. If you anticipate a certain brake pressure is needed and don't get it, it can feel like a failure, but (I believe) the automotive thinking is that in such a situation most folks would just press the pedal harder, if only out of sheer panic, and this would result in effective braking.

So the possibility of 'brake boost' failures are not [in this country at least] necessarily treated as a cause of a recall - I'm not agreeing with that, I'm just saying that I believe this is the logic applied.

In actual fact, I'm not overly concerned about it because I drive for economy and barely use the brakes in an ICE car, let alone an EV with regen. I'll trust that I would recognise such an event, and act promptly, whilst waiting for this new part to arrive. Everything we do in life is a risk, and I'm prepared to take this one (for a while) as the car has already done 2.5k and no problems.

The thing I worry about more is loss of assist in a hydraulically powered steering system [when driving my other cars]. I've had this happen twice and both times were extreeeemely fortunate that it was low speed with nothing around. You can press a pedal much harder that you normally do, but turning a steering wheel harder when you least expect it is altogether a more challenging event.
donald is offline  
post #4 of 16 (permalink) Old 07-27-2013, 05:30 AM
Banned
 
Join Date: Jul 2013
Posts: 381
RE: Brake boost vacuum pump ECU fault.

Does the brake pedal suddenly go very hard or is it a gradual thing? I know the Prius has had the odd funny turn a couple times in the 80k miles I've had it where the brake pedal is rock solid, though only when stationary. Apparently the brakes would still work but this is the reason for the recall. It sounds a very similar issue, though Toyota are super hot on getting safety issues resolved.

I didn't know about the steering wheel issue on the Fluence though. Is this a common fault? If it is, it's worrying if this is happening on a few dozen low mileage cars. I do like the Fluence and the Leaf but the Fluence is rarer and I like that and they're down to 8,500 now for a 18 month old car. I just don't want to buy into a pup though.

So do I pay the 8,000 (once I knock 'em down a bit) and the monthly rental or pay the 12,500 for a Leaf? Renault have never been particularly proactive in customer service and that worries me, esp reading about Pauls experience.

I was planning on getting a Leaf a year ago but the reduced range in winter of about 60 easy miles concerned me. The Fluence does appear to go further on a charge than the Leaf (where 100+ miles on a charge are very rare even in ideal circumstances it appears), but the car seems to be plagued by reliability issues. French car and electrics and put together in Turkey just concerns me, then reading this forum. But a cheap price and 5 year warranty entices me back.
GrumpyCabbie is offline  
post #5 of 16 (permalink) Old 07-27-2013, 05:50 AM Thread Starter
Senior Member
 
Join Date: Jul 2013
Posts: 803
RE: Brake boost vacuum pump ECU fault.

Oh.. sorry, didn't mean to confuse. I was just commenting generally that I think a brake boost failure is less of a concern to me than a steering failure.

[Previous post edited, for clarity.]

The steering on the Fluence 'sounds' like it is a pure EPS, not a hydraulic type. I've no reason to doubt its reliability (yet!!!).

I'm just saying that this brake boost possibility is no more of a concern to me (at the moment!) as driving around in my other cars, with conventional hydraulic PAS.

The one thing I am reasonably confident about is that if we early users flag up anything to Renault, that they are going to snap to attention pretty quick. I reckon they know they can't be seen to be leaving early ZE'ers in the lurch, else the whole scheme will flop in short order, so I think we can rely on some welcome 'special attention' in these early days!
donald is offline  
post #6 of 16 (permalink) Old 07-27-2013, 06:03 AM
Banned
 
Join Date: Jul 2013
Posts: 381
RE: Brake boost vacuum pump ECU fault.

Quote:
Originally Posted by donald
... so I think we can rely on some welcome 'special attention' in these early days!
There is that.

GrumpyCabbie is offline  
post #7 of 16 (permalink) Old 07-27-2013, 03:09 PM
Banned
 
Join Date: Mar 2013
Posts: 167
RE: Brake boost vacuum pump ECU fault.

Interesting discussion. I would like to think that Renault appreciates us early adopters, their difficulty is lack of sales hence jack of customers and lack of feedback, so they need us to be vocal. Going back to my brake problem, the initial situation was indeed a solid brake pedal - it actually seemed to jump back up a little. Maybe I could have forced it down but at the moment of need I think the more likely reaction is to swerve to miss what you were heading for! My repair was in two parts. The first included a "computer" and vacuum pump but the problem was not entirely solved until a one-way valve was inserted into the circuit presumably to prevent it repeating. I do wonder if the CAUSE was faulty instructions causing a component to work outside its design capability? Pure guesswork, I know, but why else would the ECU need replacing? This would also fit with the brakes apparently working again once I had stopped, switched off waiting for the breakdown truck then firing the car up again. If it had been a pure mechanical failure they would have stayed broken.

The good news is that "blue" has now passed 500 miles in my hands and ALL IS WELL.
pauledg is offline  
post #8 of 16 (permalink) Old 07-27-2013, 04:27 PM
Banned
 
Join Date: Jul 2013
Posts: 381
RE: Brake boost vacuum pump ECU fault.

Quote:
Originally Posted by pauledg
The good news is that "blue" has now passed 500 miles in my hands and ALL IS WELL.

Would you do it again or would you buy a Leaf or Mitsubishi?

How was the HV battery billing? Pain and hassle free? Easy? How was insurance? What insurance value do they want you to put on it? What happens if the car is totalled and they pay you 8,000 market value? Unlikely but crashes happen. I'd hate to pay 8,500 for a Fluence, total it, get paid out 8,000 and get a bill from Renault for 6,000 for the batteries.
GrumpyCabbie is offline  
post #9 of 16 (permalink) Old 07-27-2013, 06:20 PM Thread Starter
Senior Member
 
Join Date: Jul 2013
Posts: 803
RE: Brake boost vacuum pump ECU fault.

I was told there are, actually, two notices against the Fluence. I didn't get (wasn't given) the specifics of the second, but was lead to believe that one hinged on the other. So, as you say, maybe the second doesn't need to be done, unless something actually happened and the customer reported the matter as an event, and the software cause something else to exceed its design, per your case.

I'm going to presume Renault have the issue in hand and they'll do the right thing. We'll see if I might come to regret such confidence, but I'll go along with their efforts in the first instance.

From what you describe, it does sound like you lost vacuum assist but not the brakes. As you say, testing out what may or may not have happened is not the immediate issue, when you have an option to steer around an impending collision!



donald is offline  
post #10 of 16 (permalink) Old 07-28-2013, 03:34 AM
Banned
 
Join Date: Mar 2013
Posts: 167
RE: Brake boost vacuum pump ECU fault.

Would I do it again? Ask me this time next year....... I would not be interested in a Mitsubishi, the Leaf was a possible contender but style-wise it didn't really suit and I disliked the over gimmicky electronics and instruments. I see the Fluence as rather a Q-car, that I like! I must say the test drive in the Leaf impressed me. Strangely, I bought the Fluence without a test drive, withlout actually seeing one in the flesh.

Battery billing. First time round worked okay but it took RCI Finance three months to get it up and running, only then after I started panicking and wrote to them. This time round I haven't a clue. They're still billing me for the old car - remember, I didn't buy the present car, it was an exchange and the dealer (or Renault) should have made the necessary arrangements but my contact at Renault has been on holiday so i can't investigate just yet. I'm still paying 76 per month for 3 years and 6000 mile limit.

Insurance. I too found some comparison sites were not up to speed but did get a range of quotes from the sublime to the ridiculous, from under 200 to several thousand. However at the moment I have transfered the car onto my old insurance till it runs out, then I've been quoted 275 for a full year, a figure I can very easily better so I'll be changing. The value I proposed was 18000, allowing for purchase price of car plus full value (7000) of the battery as per RCI's instructions. The insuring of a Fluence does confuse insurers with cover for a car that depreciates plus cover for a battery that doesn't (though in reality it does). What will happen in the event of a prang is anyone's guess. Maybe the safest route would be to try insuring the car minus battery and take out a totally separate policy for the battery, but then just suppose the battery sets fire to the car, your insurers would be fighting one another!

The battery hire comes with reams of small print that could worry you to death. I don't know why RCI don't insure the battery (their battery) and add that to the rental cost and keep things simple. Any thoughts?

Just charged the car overnight after worrying about the forecast thunderstorms and a cable dangling out of the window. I used a 10A cable as this is cheaper than using the wall charger - the wall charger almost completes the charge at full price before the offpeak hour arrives. Remember the car and charger neither have any means of timing the charge, a big minus point. Woke up to find email saying battery charged to 100%, range 105.6 miles, and the light on the charge cable still indicating charging ongoing; this went out after another hour so what it was doing during that hour I don't know. I've noticed previously that the charging light suggests charge goes on for a lot longer than predicted. If the charge really does complete earlier then I'll have to plug in via an accessory timer so charging begins at 12.30 to ensure best value.
pauledg is offline  
Reply

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome