Nissan Altima Forum banner

1 - 20 of 27 Posts

·
Registered
Joined
·
12 Posts
Discussion Starter #1
I just bought a 2019 Nissan Altima and I noticed that the heated seats only work on the top part of the seat and not the bottom, is that how the car is or is there a problem with my seats?
 

·
Registered
Joined
·
178 Posts
There's a problem with the seats, or more likely the wiring if both seats are behaving the same way. Do they work at all on the low setting, or only the one cushion and only on high? If the latter, then the cushion that doesn't heat has an open element or open wire. You know this because the low setting puts the elements "in series" one after the other electrically, so if one is open then it disables both. On high the elements are "in parallel" electrically, so the good one will heat but the bad one won't.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #3
There's a problem with the seats, or more likely the wiring if both seats are behaving the same way. Do they work at all on the low setting, or only the one cushion and only on high? If the latter, then the cushion that doesn't heat has an open element or open wire. You know this because the low setting puts the elements "in series" one after the other electrically, so if one is open then it disables both. On high the elements are "in parallel" electrically, so the good one will heat but the bad one won't.
Both seats are same, and even in the low setting only the top part works
 

·
Registered
Joined
·
178 Posts
That's OE then. Let me check the WD's on Monday to see if there's a common connection that could cause both lowers not to work. The '19~20's are arranged a bit differently than the '18-downs, so I can't give you an off-the-top answer.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #7
That's OE then. Let me check the WD's on Monday to see if there's a common connection that could cause both lowers not to work. The '19~20's are arranged a bit differently than the '18-downs, so I can't give you an off-the-top answer.
That would be much appreciated, I look forward for your answer.
 

·
Registered
Joined
·
178 Posts
I managed to get a pic of the WD from a friend who has ASIST on his home comp. There doesn't appear to be any likely path that would cause one heater element to work and not the other. The '19~'20's don't use a series-to-parallel arrangement like prior models, instead there's a temperature sensor incorporated into the lower pad and the HVAC Control ("AC Auto Amp" in the diagram) cycles the heater elements at different set temperatures depending on the setting H/M/L. If you follow the power path in the diagram, 12V for both seats comes in at fuse 35 and is common to both elements. The thermostatic breaker in the lower cushion is also common (anything common to both elements can't cause a 1-cold condition). The circuit then branches to both elements and then joins back together after them, meaning they are always in parallel, never in series. The HVAC Control then provides ground to turn both elements on or an open circuit to turn both off. So the only way the back heater could possibly get warm with the lower element staying cold is if the circuit from pin 5 of the lower cushion to the junction was somehow open in both seats. That's highly unlikely. The only thing that is likely is a bad lower element in both seats. That isn't unheard of -- not to be "weight-ist", but if the previous owners were both overweight it's possible they trashed both elements without meaning to.
 

Attachments

·
Registered
Joined
·
12 Posts
Discussion Starter #9
I managed to get a pic of the WD from a friend who has ASIST on his home comp. There doesn't appear to be any likely path that would cause one heater element to work and not the other. The '19~'20's don't use a series-to-parallel arrangement like prior models, instead there's a temperature sensor incorporated into the lower pad and the HVAC Control ("AC Auto Amp" in the diagram) cycles the heater elements at different set temperatures depending on the setting H/M/L. If you follow the power path in the diagram, 12V for both seats comes in at fuse 35 and is common to both elements. The thermostatic breaker in the lower cushion is also common (anything common to both elements can't cause a 1-cold condition). The circuit then branches to both elements and then joins back together after them, meaning they are always in parallel, never in series. The HVAC Control then provides ground to turn both elements on or an open circuit to turn both off. So the only way the back heater could possibly get warm with the lower element staying cold is if the circuit from pin 5 of the lower cushion to the junction was somehow open in both seats. That's highly unlikely. The only thing that is likely is a bad lower element in both seats. That isn't unheard of -- not to be "weight-ist", but if the previous owners were both overweight it's possible they trashed both elements without meaning to.
Ohhh I see lmao😂
 

·
Registered
Joined
·
178 Posts
Btw, the heaters usually come with the lower foam pad, so they're not necessarily cheap to replace. If you're past warranty on mileage and you're handy with an ohmmeter, broken elements can be traced to locate the open spot and repaired with mylar tape and a healthy gob of the conductive paint used for rear-defogger repair. Lay paint down the center of the tape strip and then fold it over the broken area to reconnect it. Good as new once the paint sets up.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #11
Btw, the heaters usually come with the lower foam pad, so they're not necessarily cheap to replace. If you're past warranty on mileage and you're handy with an ohmmeter, broken elements can be traced to locate the open spot and repaired with mylar tape and a healthy gob of the conductive paint used for rear-defogger repair. Lay paint down the center of the tape strip and then fold it over the broken area to reconnect it. Good as new once the paint sets up.
I will try to do that or find a place to do so because I’m not that experienced with such stuff, any idea how much the dealership might charge to fix such issue? Or any other shops for this matter?
 

·
Registered
Joined
·
178 Posts
The dealership isn't likely to be willing to mess with a repair, I'm sure they'll insist on a new cushion. If you're not "way over" on mileage you might see the service manager about a "goodwill" repair, very often Nissan will either split you 50-50 or cover the part and you pay the labor. Even then, the cushions aren't cheap, looks like they're about $800 each online and $1200 list. Your best bet for a repair is a local upholstery shop, since the disassembly isn't for the faint-hearted or inexperienced. The cushion is just held in with J-hooks, but both the plastic trim and the hog rings for the seat cover are complete PIA's. It's very easy to make a mess if you don't know what you're doing.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #13
The dealership isn't likely to be willing to mess with a repair, I'm sure they'll insist on a new cushion. If you're not "way over" on mileage you might see the service manager about a "goodwill" repair, very often Nissan will either split you 50-50 or cover the part and you pay the labor. Even then, the cushions aren't cheap, looks like they're about $800 each online and $1200 list. Your best bet for a repair is a local upholstery shop, since the disassembly isn't for the faint-hearted or inexperienced. The cushion is just held in with J-hooks, but both the plastic trim and the hog rings for the seat cover are complete PIA's. It's very easy to make a mess if you don't know what you're doing.
Okay thank you!
 

·
Registered
Joined
·
8 Posts
I took my MY19 SV to dealer on Monday because my heated seats weren’t working either. Only the top part of the drivers seat, and the passenger seat did not work at all. They just informed today that they have to order a module that controls the heated seat. Said it has gone bad. Car will be ready for pick up tomorrow.

Will see how this works out. My car is still under warranty as i only have 10k miles on it.
 

·
Registered
Joined
·
12 Posts
Discussion Starter #16
I took my MY19 SV to dealer on Monday because my heated seats weren’t working either. Only the top part of the drivers seat, and the passenger seat did not work at all. They just informed today that they have to order a module that controls the heated seat. Said it has gone bad. Car will be ready for pick up tomorrow.

Will see how this works out. My car is still under warranty as i only have 10k miles on it.
Did they by any chance tell you how much did that module cost? Because my dealership gave me an estimate of around 1700-2300k to fix my seats and they said it is most likely the module too.
 

·
Registered
Joined
·
8 Posts
Did they by any chance tell you how much did that module cost? Because my dealership gave me an estimate of around 1700-2300k to fix my seats and they said it is most likely the module too.
I just asked my SA how much does it cost and he said 1500.
 

·
Registered
Joined
·
178 Posts
Unless the WD is lying, there's simply no way the control module can cause one cushion to work and the other not. An open in the lower cushion could leave the seatback element working by itself, or vice versa. However, you can see the elements are wired in parallel to the controller. That means a bad controller can only render both elements inop, not just one. Sounds to me like the technician has made unwarranted assumptions without checking the WD.
 

·
Registered
Joined
·
8 Posts
Unless the WD is lying, there's simply no way the control module can cause one cushion to work and the other not. An open in the lower cushion could leave the seatback element working by itself, or vice versa. However, you can see the elements are wired in parallel to the controller. That means a bad controller can only render both elements inop, not just one. Sounds to me like the technician has made unwarranted assumptions without checking the WD.
Good info. All I know is it better be working when I get it back.
 
1 - 20 of 27 Posts
Top