Heated seats not working
10-25-2021, 04:47 PM
#1
Junior Member
Thread Starter
Heated seats not working
I have a error code in N25/7 module. B22A012 “short circuit to positive”.
Anyone have information on probable causes of this?
Seat heat element broken, module broken? What part has short circuit to positive?
Anyone have information on probable causes of this?
Seat heat element broken, module broken? What part has short circuit to positive?
10-27-2021, 12:55 AM
#3
Junior Member
Thread Starter
11-09-2021, 05:37 PM
#4
Junior Member
Thread Starter
The best problems are the once that sort them self out.
Before ordering a new module I decided to measure the seat heater pads. I disconnected all 4 and measured. 4ohms on backrest pad and 22ohm on seat pad. With all the pads disconnected I turned on the heat and now suddenly the passenger side button stayed illuminated!
I connected one pad back at the time and all was OK.
For the driver side the button lights went out after maybe 5sec with no pad connected. When I reconnected 1 pad the light stayed on, then reconnected other pad and all was now working OK!
Magic! Seat heater is now back and working, I will check with Xentry later to see if the error code is now gone.
Feels like the module needed some type of restart or something.
Before ordering a new module I decided to measure the seat heater pads. I disconnected all 4 and measured. 4ohms on backrest pad and 22ohm on seat pad. With all the pads disconnected I turned on the heat and now suddenly the passenger side button stayed illuminated!
I connected one pad back at the time and all was OK.
For the driver side the button lights went out after maybe 5sec with no pad connected. When I reconnected 1 pad the light stayed on, then reconnected other pad and all was now working OK!
Magic! Seat heater is now back and working, I will check with Xentry later to see if the error code is now gone.
Feels like the module needed some type of restart or something.
11-09-2021, 06:23 PM
#5
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PFL205.064 with M276.823 (Oil pump solenoid defeated)
The best problems are the once that sort them self out.
Before ordering a new module I decided to measure the seat heater pads. I disconnected all 4 and measured. 4ohms on backrest pad and 22ohm on seat pad. With all the pads disconnected I turned on the heat and now suddenly the passenger side button stayed illuminated!
I connected one pad back at the time and all was OK.
For the driver side the button lights went out after maybe 5sec with no pad connected. When I reconnected 1 pad the light stayed on, then reconnected other pad and all was now working OK!
Magic! Seat heater is now back and working, I will check with Xentry later to see if the error code is now gone.
Feels like the module needed some type of restart or something.
Before ordering a new module I decided to measure the seat heater pads. I disconnected all 4 and measured. 4ohms on backrest pad and 22ohm on seat pad. With all the pads disconnected I turned on the heat and now suddenly the passenger side button stayed illuminated!
I connected one pad back at the time and all was OK.
For the driver side the button lights went out after maybe 5sec with no pad connected. When I reconnected 1 pad the light stayed on, then reconnected other pad and all was now working OK!
Magic! Seat heater is now back and working, I will check with Xentry later to see if the error code is now gone.
Feels like the module needed some type of restart or something.
11-28-2021, 04:25 AM
#6
Junior Member
Thread Starter
Apparently the problem was not permanently solved. Sometimes the heated seats are working but most the time not.
I have checked all cabling at it seem to be fine.
However I found that my seats have 3 heater pads.
does anyone know what the resistance of each heater element should be?
I checked WIS but I don’t find any information of this, only how to replace them. However I am not very familiar with WIS so there might be information available but I can’t find it.
Otherwise might be some intermittent issue with the control module but I want to rule out the heater pads before buying new control module for test.
I have checked all cabling at it seem to be fine.
However I found that my seats have 3 heater pads.
does anyone know what the resistance of each heater element should be?
I checked WIS but I don’t find any information of this, only how to replace them. However I am not very familiar with WIS so there might be information available but I can’t find it.
Otherwise might be some intermittent issue with the control module but I want to rule out the heater pads before buying new control module for test.
01-03-2022, 06:10 AM
#7
Junior Member
Thread Starter
I have now also replaced the Control module without any success. The error code keeps coming intermittently.
I have located a break in one of the 3 driver seat heater elements and disconnected this one. The problem still persists.
Does anyone have an idea of what could be the cause of the “short circuit to positive” error code?
I have located a break in one of the 3 driver seat heater elements and disconnected this one. The problem still persists.
Does anyone have an idea of what could be the cause of the “short circuit to positive” error code?
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02-02-2022, 05:46 PM
#8
Junior Member
Thread Starter
does anyone know what the resistance of each heater element should be?
or what resistance is expected for the entire seat (heat elements are connected in parallel)?
I would appreciate this information if anyone have it available or can measure on their seats.
or what resistance is expected for the entire seat (heat elements are connected in parallel)?
I would appreciate this information if anyone have it available or can measure on their seats.
02-06-2022, 03:12 PM
#9
Junior Member
Thread Starter
I would really appreciate some support on this issue if there is any.
the issue is still intermittent.
when heating works and connected with Xentry the current withdrawal of the heating elements is displayed OK. But when the fault appears, usually just need to cycle the ignition once the current is displayed steadily at 25.4A, same value as when ignition is OFF.
Xentry information says the current value comes from rear SAM over LIN bus. But how can SAM read the current over the heater elements and why does it state 25.4A also when heater is OFF??
can there be a fault with the rear SAM?
the issue is still intermittent.
when heating works and connected with Xentry the current withdrawal of the heating elements is displayed OK. But when the fault appears, usually just need to cycle the ignition once the current is displayed steadily at 25.4A, same value as when ignition is OFF.
Xentry information says the current value comes from rear SAM over LIN bus. But how can SAM read the current over the heater elements and why does it state 25.4A also when heater is OFF??
can there be a fault with the rear SAM?
