Heated seats not working

[2014 Sierra SLT]

My truck is at the dealer now. They are telling me they checked the seats with an IR meter and one is at 90 degrees the other at 80. Wish I knew what the temp was on those who have seats working fine.

My dealer told me that normal operation was between 88-90 degrees. I asked if he could explain how a 90 degree seat was supposed to heat a 98.6 degree rear end. We both had a laugh, but it was a rather strained laugh. And no, he couldn't explain it.

[redwngr]

As I recall, may a** will sweat on a leather seat on an 80 degree day.

 

Just sayin....

[pm26]

My servicing GMC dealer fixed my heated seat problem.

 

As indicated in the service ticket below; pass. seat was working normal pulling 6 ohms while driver's seat (the one that was not working) was found inoperable (INOP) pulling more than 16.4 ohms. They replaced both lower and seat back elements in the driver's seat.

 

Read the details at the bottom of the service ticket below. (you may need to save the photo and increase the viewing size to read it);

It is the current that produces the heat in the heating element. So at constant voltage (about 14 volts for these trucks with the engine running) the current available for the element with 2.5 times the resistance of the other one will be 2.5 times less. (R=V/I)

 

The elements do not pull "ohms" which are units of resistance, but amperes, which are units of current. At constant voltage, the amount of current flowing through the element (and amount of heat) will be inversely proportional to resistance)

Edited February 27, 2015 by pm26

[pm26]

I would like to mention that GM uses heated seat modules which need to be programmed when a new module is installed.

This is the case with my 2009 Impala LTZ (I do not have heated seats in my truck). I almost have a feeling that GM deliberately programs these control units to flow very low current through the heating elements, thus producing low heat.This of course help guard against overheating and possible injury to a person sitting in a heated seat. I know that Volkswagen had some lawsuits because of runaway heated seats that actually burned through the upholstery and scorched the asses of some unfortunate seat occupants when turned on high. I wonder if there would be complaints here if this was happening on these GM trucks?

Edited February 27, 2015 by pm26

[Rewillia]

It is the current that produces the heat in the heating element. So at constant voltage (about 14 volts for these trucks with the engine running) the current available for the element with 2.5 times the resistance of the other one will be 2.5 times less. (R=V/I)

 

The elements do not pull "ohms" which are units of resistance, but amperes, which are units of current. At constant voltage, the amount of current flowing through the element (and amount of heat) will be inversely proportional to resistance)

 

Ohms resistance is how they determine if the elements are working or not.

 

Read the report below, bottom section with the technician's statement indicating variance in Ohms readings for driver/passenger seat which confirmed fault. This led to my servicing GMC dealer replacing bad seat heating elements on driver's seat as a warranty item.

[Green 1364]

Update!!!! My truck was at the dealer for heated seats and several other issues. The bottom element in the drivers seat read over 16 ohms (bad). They called GM and they did a HVAC update the back is warmer then it ever was waiting for the new bottom element to come in. Make sure your dealer is checking the ohms and does a HVAC update. I don't know how long the update is out but it helped the back so far.

 

Here is what they did...Reprogrammed BCM (WCC #S1929) HVAC MODULE (WCC #99EF2)

[pm26]

 

Ohms resistance is how they determine if the elements are working or not.

 

Read the report below, bottom section with the technician's statement indicating variance in Ohms readings for driver/passenger seat which confirmed fault. This led to my servicing GMC dealer replacing bad seat heating elements on driver's seat as a warranty item.

No argument here, measuring the resistance of the circuit can pinpoint a problem when compared to an established specification showing maximum resistance acceptable. It is a common diagnostic technique. It was just the way you worded it "pulling ohms" that sounded confusing.

[Rewillia]

No argument here, measuring the resistance of the circuit can pinpoint a problem when compared to an established specification showing maximum resistance acceptable. It is a common diagnostic technique. It was just the way you worded it "pulling ohms" that sounded confusing.

Your correct, I did use the wrong term "pulling" vs. "reading" or "resistance".

 

I'll be the first to admit that I am not that familiar with electrical/electronics and apparently neither was the technician that worked on my truck heating seat problem the 1st time I took the truck in with a complaint of it not working. That's when the GM dealer told me the seats were "working normal as designed".

 

It was only after I filed a case with the BBB-Autoline that someone from GM called me and arranged for my truck to be taken back in a 2nd time that the servicing dealer confirmed the fault (as per the service ticket above) and replaced the elements. The service report shows that the "customer" has (had) an open case with GM at the time the vehicle was taken in the second time to have the problem addressed.

[pm26]

After reading all these complaints it seems to me that the root cause of these failures is poor quality/bad design of the heating elements themselves.

Can you imagine if a $ 100 electric blanket worked like this? Would you accept the explanation that it performs normally if it barely got warm after 30 minutes?

Edited March 1, 2015 by pm26

[TJay74]

My truck is going into the dealer in the coming weeks for the headlight update, I plan on having my HVAC module updated as well since mine has the original production release in it where the HVAC doesn't work correctly under remote start operation.

[tbarn]

Heating element spec is 5-10 ohms. No more, no less,if anyone cares. New one are supposed to more "robust".

Edited March 1, 2015 by tbarn

[whaler]

So.....we all know these seats don't work well. What are we doing about it? Just accepting this? Not me....going back in to blast the dealer tomorrow .

 

 

Sent from my iPhone using Tapatalk

[4x4Hank]

We really should all be blasting Chevy/GMC instead of the dealers. All they can do is what is allowed by corporate. It's obvious that there is a design flaw. I am not happy at all with the heat that my seat puts out. Maybe some type of group action would be better than individual complaints. I just don't know what kind of action would be effective.

Hank

[TJay74]

As said, either ohm out your seat elements or have the dealer do it. If the element it outside of the spec of 5-10 ohm then it needs to be replaced.

[Rewillia]

Guys,

 

I'll mention it again. My driver's seat heating stopped working and the end result was GM fixed them as a warranty item. I am only mentioning this as to share my experience and possibly help others who are experiencing a similar issue.

 

 

When I discovered my driver's seat heater was not working I took it into my servicing GMC dealer, they kept it for a day then called me to come pick it up stating they had checked them and found that "the seat heaters are working as designed". Not being satisfied with such an explanation and knowing that the seat was not heating as it did the previous winter, I filed an online complaint with the BBB-Autoline.

 

Within just a few days after filing my complaint, I was called by a GM corporate rep who both questioned the nature of my complaint and listened to my explanation of what I had and was experiencing. She apologized for what I was experiencing and then asked if I would give them a couple of days to work on my issue internally with GM which I agreed to. A few more days later, GM called me back, stated they had opened a "case" for me and asked if I would bring my truck back in (to the same dealer) for further evaluation to include GM's corporate technical team support. I did so and the results were that they verified the fault and replaced both the seat bottom and seat back heating elements in my driver's side seat which repaired the problem as a warranty item (please read post # 148 above which includes the GMC service tech's finding and the repair performed).

 

Since then, both my driver and passenger seat heaters work and they work correctly such that I will turn them down from the highest setting after a few minutes of use when driving (they get hot just like they did when I purchased the truck new in Dec 2013).

 

BBB-Autoline works for consumers and it exist for circumstances just like this!

 

http://www.bbb.org/council/programs-services/dispute-handling-and-resolution/bbb-auto-line/

Edited March 6, 2015 by rewillia