Strange Issue with Rear-Seat Heaters
Thread Starter
Member
Joined: Dec 2010
Posts: 158
Likes: 0
From: Charlotte, NC
'15 GL350 Bluetec
Strange Issue with Rear-Seat Heaters
Not to make this too long a story, but some background...
I have a 2012 ML350BTC with P2, heated Rear Seats and a number of other options. From almost Day 1, I have had issues with the rear seat heaters. They have worked only sporadically and when they did, they sometimes heated, sometimes just stayed lit (the switches) but didn't heat, or whatever. Of course, during my first visit to the dealer, there was no fault found. This was in August of '12.
Fast forward to this fall, when my daughter shot video of the switches coming on when pressed but quickly shutting down - a ha! Video evidence for the NFF that would be inevitable (or so I thought). Took it in, and they in fact did find the fault, or at least agreed there was a fault.
The dealer had the ML for several days. Replaced the controller, the switches, updated the software. Didn't work. Ordered and installed new heating pads for both seats. Didn't work.
Got a call today from the technician - they found the problem!! Recall, P2 (at least in MY 2012) had Interior Ambient Lighting. I keep mine set on the Neutral color, at the dimmest (1) level. It seems that with the ambient lights set like this, the rear-seat heat controller is "confused" and will not function properly (remember, all these things run through the same CAN). Dead-serious. Seems that my local (dealer) technician along with the shop manager was in a long discussion with an M-B engineer and they have experienced this issue with one other vehicle. Apparently it is software related, and they anticipate a bug fix in the next release.
I post this not only for those that may have rear seat heater issues, but also as an example of how there could easily be other strange occurrences that don't necessarily throw fault codes, or that would otherwise be not resolved. Talk about weird!!
I have a 2012 ML350BTC with P2, heated Rear Seats and a number of other options. From almost Day 1, I have had issues with the rear seat heaters. They have worked only sporadically and when they did, they sometimes heated, sometimes just stayed lit (the switches) but didn't heat, or whatever. Of course, during my first visit to the dealer, there was no fault found. This was in August of '12.
Fast forward to this fall, when my daughter shot video of the switches coming on when pressed but quickly shutting down - a ha! Video evidence for the NFF that would be inevitable (or so I thought). Took it in, and they in fact did find the fault, or at least agreed there was a fault.
The dealer had the ML for several days. Replaced the controller, the switches, updated the software. Didn't work. Ordered and installed new heating pads for both seats. Didn't work.
Got a call today from the technician - they found the problem!! Recall, P2 (at least in MY 2012) had Interior Ambient Lighting. I keep mine set on the Neutral color, at the dimmest (1) level. It seems that with the ambient lights set like this, the rear-seat heat controller is "confused" and will not function properly (remember, all these things run through the same CAN). Dead-serious. Seems that my local (dealer) technician along with the shop manager was in a long discussion with an M-B engineer and they have experienced this issue with one other vehicle. Apparently it is software related, and they anticipate a bug fix in the next release.
I post this not only for those that may have rear seat heater issues, but also as an example of how there could easily be other strange occurrences that don't necessarily throw fault codes, or that would otherwise be not resolved. Talk about weird!!
