Niro
Posts: 1
Joined: Sun Dec 27, 2020 9:09 am
Delivery Date: 27 Dec 2020

Re: has your Leaf's PTC heater failed? reply here

Sun Dec 27, 2020 2:27 pm

I purchased a 2015 Tekna Leaf (in the UK) in early Dec (2020) and have just managed to replace a faulty PTC heater (27th Dec 2020) and, for now, I have heat! I say "for now" as I do not know if the failure was to do with the PTC module itself or the climate control software telling it to run too hot in a certain scenario and therefore destroying it. The original unit in my car was dated Oct 2014 and I have replaced it with a Jan 2016 PTC heater module (dates are on the PTC heater stickers). So far it is working, but if it does fail in the near future, I will be back to update in the forum.

Car was purchased with a known PTC heater issue. No heat, no kW consumption increase in climate control dial on energy use screen, error B2777 on LeafSpy which persisted even when attempts were made to clear the error code.

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Prev owner found the car was out of warranty and cost for repair was high - I suspect quotes around £2.5-3k from Nissan.

I did some research and found little in the way of DIY replacements for RHD cars. The various factory service manual chapters (https://www.nicoclub.com/nissan-service-manuals) prepared me for a dash out job and that is what I embarked on. Please note that I followed the suggested precautions in the manual (decent Class 0 gloves when working near high voltage fittings and also removing the 12V battery and the traction battery fuse. I take no responsibility for any work you might do based on this. Please follow the instructions in the manual at the link shared above).

Prior to taking the dash apart, I followed a couple of test processes in the manual (pages HAC104 and 105) to check that the connectors and cables were okay between the aircon controller and the PTC heater. Additionally, I also sprayed contact cleaner on the connector plugs and fitted/removed them a few times hoping that it was going to fix the issue. The B2777 error code mentions an issue with LIN comms and so I was hoping that this was the fix. Unfortunately it didn’t make a difference.

I then plugged just the comms wiring from the car into the replacement PTC heater I purchased used off eBay. I was happy to see the error code change to B2772 which is to do with PTC heater voltage. At this stage I had not disconnected the batteries, I just used the class 0 gloves when taking off the data connector but did not tamper with any HV items.

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This meant that the comms part of the original PTC heater must have stopped working and the replacement one was atleast communicating with the car! I was worried as there was a chance the used eBay unit wouldn’t work or that it would not be compatible with the older aircon control unit my car had.

With the car made safe and still wearing class 0 gloves when near HV items I proceeded to do the below:

I looked at how to get the PTC unit out without taking the dash off completely. I followed steps in the manual (Section IP) to take off the center console and the lower panel by the pedals. Then took other bits off and opened up a couple of holes shown in number 3 in the pic below to gain access to some screws that would otherwise only be accessible with the dash apart.

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I didnt have the car raised and on stands so it made the removal of the HV connection to the heater a bit of a pain. without damaging anything, I managed somehow to release the little tab so that I could press the release tab of the plug and it did come off. The above pic shows the tab release in detail. Also there was a cable tie attached to the heater cable near the battery area that needed to be released. Again that would have been a lot easier with access under the car.

With these steps taken, I was able to finally take off the two screws attaching the PTC heater to the aircon unit and as I expected it was not able to come out completely due to the parking brake pedal.

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There are some other steps I took to loosen the parking brake cable, remove the parking brake pedal base off the bulkhead and maneuver the assembly while also pressing/depressing the pedal to allow the PTC heater to clear the lot. This was a bit tedious but just takes patience.

To avoid taking the rest of the dash apart, I decided to cut a black wire that is attached to the PTC heater unit. Technically I could remove this at the PTC heater end (there is a screw but it has a blue filling on the screw so that it cannot be tampered with). I decided not to mess around with the PTC itself and opted to solder and seal up this cable that is a connection to ground.

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Finally the replacement PTC heater is in place.

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I had to put everything back in place prior to testing. Once all was put back together and the fuse back in plus the 12V battery hooked up, I checked out what LeafSpy had to say.

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No Errors!! I went for a test drive to check that everything was working. The PTC heater works and I can actually feel warm air coming through the vents. The energy consumption shown for the climate control also climbed up which it didn't do previously. Not sure how long this will last, but for now I lowered the preheat temp to 16 degrees C as that would be enough to clear the windscreen. I would love to know what kills these PTC heaters in the first place.

This took me just over half a day. I had budgeted a lot more time as I expected to have to take the whole dash apart. Lot of fiddly bits and I have a lot of muscle pains from having to push and pull at funny angles. Maybe taking the front seat off would have made things a lot easier! :)

Daklein
Posts: 80
Joined: Fri Sep 06, 2019 7:58 pm
Delivery Date: 02 Sep 2019
Location: Hartland, MI

Re: has your Leaf's PTC heater failed? reply here

Sun Dec 27, 2020 6:40 pm

Nice job Niro!
2014 Leaf S Plus :o (12/2019 62kWh swap!)

bearer
Posts: 12
Joined: Sun Sep 11, 2016 12:56 am
Delivery Date: 11 Sep 2016
Leaf Number: 012853

Re: has your Leaf's PTC heater failed? reply here

Sun Dec 27, 2020 10:41 pm

Nice detailed post, thanks for taking the time to document it!
Niro wrote: I would love to know what kills these PTC heaters in the first place.
random long shot; try contacting bigclivedotcom for a post-mortem?

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