DTC C1A66 0109 Master pressure sensor (replacement)

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ElectraBlue

New member
Joined
Apr 7, 2015
Messages
3
Location
Norway
Hi ! My 2011 Seattle Leaf have been working beautifully here in its new country in Norway. A few months ago I got two yellow warning lights, the triangle and the brake symbol. Using the Leaf Spy I could read the DTC code "C1A66 0109 Master pressure sensor". Nissan in Norway have "banned" the imported US-Leafs and we get very litte help at the Dealer. They just told me they didn`t know what the error was! Have anybody any experience with this error? I have to pay for all the error search and replacement at $ 150 pr. hour if I give the car to the dealer.
I did find some sensors through courtesyparts.com but I am not sure if these could be the source of the DTC code?
http://www.courtesyparts.com/leaf-p...ster-cylinder/-c-10282_10283_10329_10333.html

Any input would be appreciated!
 
The Master Cylinder has a pressure sensor. I have uploaded the pages from the brake manual for you to troubleshoot the problem:
http://www.qfrf.com/BR87_95.pdf" onclick="window.open(this.href);return false;
 
Thank you! I will try this procedure over the weekend and let you know what I find out! It looks like a fair bit of work to locate the cause of the error...
 
What was the result of your troubleshooting? I found I have this same fault code on my 2011 SL using Leaf Spy Pro and the dealer wants to charge me $2000 to replace the entire master cylinder/brake booster. I tried getting Nissan corporate to do a good-will repair and they shut me down as well as I'm 4 months out of warranty (though I'm only at 31k miles).
 
Good-will is not part of Nissan's vocabulary...

snowpunter said:
I tried getting Nissan corporate to do a good-will repair and they shut me down as well as I'm 4 months out of warranty (though I'm only at 31k miles).
 
Was the dealer able to vefify that the master cylinder is in fact defective, just not a bad sensor? Or, are they, like many auto repair shops, "shotgunning it", replacing everything that it could possibly be just to avoid a call-back? Is the master cylinder leaking? Have you felt anything strange with the brake pedal? Have you tried clearing the error code to see if it comes back? I would sure hate to shell out $2000 for a new master cylinder and have the code come back later for something simple, like a low 12 volt battery or super capacitor issue.
If they can guarantee its the master cylinder, I'd be shopping on car-part.com for a replacement from a yard. I see them as cheap as $450.
 
Dealer claims the brake booster has some sort of electrical fault.

I began feeling an issue a few months ago where the handoff between regen and hydraulic braking was very abrupt around 15 MPH and the brake pedal became very loose at that speed. I thought that this was normal and expected behavior until the yellow brake warning light came on at the end of last month. I took it to the dealer and they said the brake booster was going bad and wanted to $2k to replace it.

After some google-fu I saw the part (which includes the master cylinder) is MSRPing for almost $2k. Holy nutballs batman! Leaf Spy Pro pulled the DTC code mentioned in this thread. I've yet to go through the steps mentioned in the diagnosis PDF posted here (many thanks to the person who posted it) but that's on my to-do list for this weekend.

No leaks that I can see, I've tried clearing the error code in the app to no avail. Is there an alternate way of clearing codes other than through Leaf Spy Pro?
 
I'm getting the exact same problem on my 2011 Leaf. In my case, I didn't drive it for a couple of weeks and during that time the 12v battery went flat. After charging it up all was fine except I noticed the yellow warning light on the dash, and LeafSpy is now reporting the "C1A66 0109 BRAKE Master Pressure Sensor BR-89 code". I can't clear the code either, so I'm presuming that I won't be able to do this until the problem is resolved. The car drives fine (in brake fail-safe mode I suppose) but you can definitely notice that brake regen is gone - engine regen is unaffected.

I haven't taken the car to my dealer yet, but my working assumption is that the brake pressure sensor needs replaced. I live in the UK and unfortunately this part is over £500 including tax...that's not for the whole master cylinder, just the sensor! There don't seem to be any aftermarket alternatives, hence the high prices I suppose. Shame on Nissan for price gouging though, when the same part is available in the US for $300 or so, which is well under half the UK price. I'm considering taking a risk and importing the part from eBay and trying to fit myself, but I'm not much of a mechanic and the brake cylinder doesn't look that easy to get at. I might find an independent garage to do it for me. This whole episode is a bit annoying seeing as my car is not yet 4yrs old with only 23k miles, and actually drives fine without brake regen...and if I pay dealer prices to repair this fault, the recovered electricity during the remaining life of the car will come nowhere near to approaching the repair cost! I wouldn't bother except I won't be able to sell the car unless I fix it!
 
This is a little confusing... The only type of regen there is on a Leaf is via the electric traction motor, which acts a a brake by being turned in to a generator rather than a motor by the controller and inverter...

DivineComedian said:
The car drives fine (in brake fail-safe mode I suppose) but you can definitely notice that brake regen is gone - engine regen is unaffected.
 
Ok - what I'm referring to is the regen you get when you hit the brakes as opposed to just taking your foot off the accelerator. In my Leaf, coasting at speed in ECO mode causes some 'engine' regen, but I get no additional regen by hitting the brakes, the absence of which is noticeable on the energy monitor.

If both of these 'regen' operations are actually enabled by the traction motor, then I wasn't aware of that and I stand corrected! I had assumed that the brake system had its own additional recovery system.
 
I had this issue as well on a 2012. My guess is that there is a faulty part and eventually there will be a class action suit to force nissan to provide some coverage. Hopefully nobody gets injured or does from this in the meantime
 
My dealer wants 460.00 plus 575.00 to replace the sensor. I found them at Amazon.com for 149.99.

They also told me that it takes 5 hours to change it because it's "buried" but I found that it's attached to the bottom of the master cylinder, I can reach it standing beside the car!

Has anyone tried to change this part themselves?


https://www.amazon.com/Pressure-Sensor-47240-AL500-Infiniti-Nissan/dp/B01AOLX8ZS
 
I paid £48.50 for the sensor as nissan want loads of money for it, but i just cant work out how to pull the plugs of the sensor as you have to test which one is broken as there are two next to each other.
816327420e003066b094414d56bb21b16ff46b1ac780673f09034805958a5dc761ba6a2f.jpg
 
This is a bit cheaper Rick

http://www.ebay.co.uk/itm/Brake-Fluid-Pressure-Sensor-47240-AL500-fits-Infiniti-M35H-QX70-FX-Nissan-Leaf-/301725142869?hash=item4640384f55:g:wbcAAOSwT6pV3~J~
 
I have this fault on my leaf. There's no confirmation that a new Sensor fixed it?
Can someone confirm what the fault actually is and how to cure it?
I purchased a new sensor for my 2013 leaf and tried it in each of the two circuits without taking out the old ones.
When i cleared the DTC's on the right hand sensor (looking into the engine bay) i got 3 back, on the left hand sensor just the one, so am guessing the fault is with the left one, or its attendant circuity. The new sensor still produced:-
>C1A66 0109 BRAKE Master Pressure Sensor BR-89

Can anyone help me further?
Regards
Stuart
 
Hi JK, funnily enough I have been in touch with the chap that with the youtube video, his just worked after replacing the sensor. I have now replaced mine and i still have the same fault :-(
Anyone else have any ideas? Or do i have to take it to Nissan. Is it something that only "CONSULT" can fix?
Cheers
Stuart
 
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