ElectraBlue
Posts: 3
Joined: Tue Apr 07, 2015 3:51 am
Delivery Date: 07 Dec 2011
Leaf Number: 004852
Location: Norway

DTC C1A66 0109 Master pressure sensor (replacement)

Tue Apr 07, 2015 5:37 am

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-parts-ze0-2011-2012/genuine-nissan-parts/brake/460-brake-master-cylinder/-c-10282_10283_10329_10333.html

Any input would be appreciated!

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keydiver
Posts: 1080
Joined: Mon Sep 05, 2011 1:04 pm
Delivery Date: 08 Dec 2011
Leaf Number: 16484
Location: Hobe Sound, Florida
Contact: Website

Re: DTC C1A66 0109 Master pressure sensor (replacement)

Tue Apr 07, 2015 10:30 am

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
2012 Glacier Pearl SL - Delivered December 8, 2011
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ElectraBlue
Posts: 3
Joined: Tue Apr 07, 2015 3:51 am
Delivery Date: 07 Dec 2011
Leaf Number: 004852
Location: Norway

Re: DTC C1A66 0109 Master pressure sensor (replacement)

Tue Apr 07, 2015 12:56 pm

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...

snowpunter
Posts: 5
Joined: Sat Dec 27, 2014 9:43 pm
Delivery Date: 27 Dec 2014

Re: DTC C1A66 0109 Master pressure sensor (replacement)

Fri Jul 24, 2015 8:27 am

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).

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TomT
Posts: 10607
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Delivery Date: 01 Mar 2011
Leaf Number: 000360
Location: California, now Georgia
Contact: Website

Re: DTC C1A66 0109 Master pressure sensor (replacement)

Fri Jul 24, 2015 9:48 am

Good-will is not part of Nissan's vocabulary...

snowpunter wrote: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).
59,991 miles/12 bars/289 Gids/68.54 AHr/101% SOH/101.64% Hx 7May15 w/ new Lizard (barely made the warranty).
71,770 miles/12 bars/256 Gids/59.04 AHr/88% SOH/87.92% Hx 3Mar16 at lease return.

Now driving a 2016 Volt Premier.

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keydiver
Posts: 1080
Joined: Mon Sep 05, 2011 1:04 pm
Delivery Date: 08 Dec 2011
Leaf Number: 16484
Location: Hobe Sound, Florida
Contact: Website

Re: DTC C1A66 0109 Master pressure sensor (replacement)

Fri Jul 24, 2015 3:37 pm

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.
2012 Glacier Pearl SL - Delivered December 8, 2011
10kW Solar PV for recharging!
2006 Prius with Hymotion 5kWh PHEV upgrade
Tesla 70D | Titanium Metallic | Matte Obeche Wood Décor| All Glass Panoramic Roof
Tesla Model 3 Pre-Ordered!

snowpunter
Posts: 5
Joined: Sat Dec 27, 2014 9:43 pm
Delivery Date: 27 Dec 2014

Re: DTC C1A66 0109 Master pressure sensor (replacement)

Mon Jul 27, 2015 8:56 am

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?

DivineComedian
Posts: 2
Joined: Mon Jul 27, 2015 2:09 pm
Delivery Date: 27 Jul 2015

Re: DTC C1A66 0109 Master pressure sensor (replacement)

Mon Jul 27, 2015 2:28 pm

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!

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TomT
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Re: DTC C1A66 0109 Master pressure sensor (replacement)

Mon Jul 27, 2015 3:37 pm

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 wrote: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.
59,991 miles/12 bars/289 Gids/68.54 AHr/101% SOH/101.64% Hx 7May15 w/ new Lizard (barely made the warranty).
71,770 miles/12 bars/256 Gids/59.04 AHr/88% SOH/87.92% Hx 3Mar16 at lease return.

Now driving a 2016 Volt Premier.

DivineComedian
Posts: 2
Joined: Mon Jul 27, 2015 2:09 pm
Delivery Date: 27 Jul 2015

Re: DTC C1A66 0109 Master pressure sensor (replacement)

Tue Jul 28, 2015 10:24 am

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.

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