Heated Seats not heating
#1
12-18-2010, 08:37 AM
Heated Seats not heating
Both seats don't heat up.
I had recently checked all fuses in the driver side door fuse panel, all good.
Do the seats have a 'check light'?
Do they have a separate fuses or relay?
Is VAGcom having anything on them?
I had recently checked all fuses in the driver side door fuse panel, all good.
Do the seats have a 'check light'?
Do they have a separate fuses or relay?
Is VAGcom having anything on them?
#3
12-19-2010, 06:55 PM
Could be an electrical connection thing I guess, but most times I've heard about busted seat heaters its a broken heating element. The wires that run through the seat are thin and get brittle over time. Kneeling on the seat or anything like that is enough to snap the wire and break the circuit that makes them heat up. I dunno if there's a way to fix them or not?
#4
12-19-2010, 06:56 PM
I will try to find the wiring diagram; will post as pdf if I find them.
In the meantime: aside from 'touch' how can I tell if they work? Are the wheels lighting up when turned from zero to 1(to 5)?
Mine is a 1996, but they sure look the same as in my 98 and even A6.
In the meantime: aside from 'touch' how can I tell if they work? Are the wheels lighting up when turned from zero to 1(to 5)?
Mine is a 1996, but they sure look the same as in my 98 and even A6.
#5
12-19-2010, 07:34 PM
#6
12-20-2010, 10:06 AM
Troubleshooting heated seats
I haven’t found a write up for troubleshooting non working seat heaters.
Basic causes for the failure are:
Second: check if adjuster wheel lights up (mine doesn’t).
Considering that both seat heaters are not working and based on the wiring diagrams, I plan to attack the issue in the following way, referring to driver’s seat diagram/locations:
1. Check fuses S5 (assume main panel location) and S244 (fuse 44; in ‘fuse holder’, also assume main panel). This would be a most likely cause, but I had checked all fuses recently, therefore I have little hope that this is it.
2. The adjusters (E94) have built in bulbs (to illuminate the adjustment wheel). In my case, both lights are not working. Since they seem to be independent of anything else, this may be an additional pointer. All they have is ground 135 (0.5mm brown) and dimmed voltage from the instrument cluster combination processor J218 (0.35mm Grey/blue).
3. There are actually 3 heating elements per seat: seat, backrest, side bolster. If non of the 3 work, it points towards a problem ‘upstream’. So let’s look there first. They are getting their voltage from the T6r wire connector, 6 point, white, left A pillar, which are connected with 2 wires to the E94 (left)/E95 (right) adjuster. Let’s start there.
4. Take the adjusters out of the dash.
5. The diagram shows 7 connections/wires. Since I don’t have heated steering wheel or multifunction steering wheel, one is not used.
7. The green 6 point wire connector under the driver seat (T6t) can be checked for:
9) Since the side bolster elements Z31 are not temperature controlled, they can be checked directly (resistance), either directly on the elements or indirectly between green wire connector T6t/4 and T6t/3.
10. The temperature sensor G59 seems to have 4 connections is likely physically close to the seat heating element Z6 itself. 3 wires Black/White (0.5mm), Black/yellow (1.5mm), Brown/black (0.5mm) and a wire to the T2a double wire connector that connects the backrest heating element Z7.
11. Elements Z6 and Z7 are in series, so if one fails, both go out.
Chime in with any comments/corrections/photos/suggestions.
I currently don’t have access to the car. I will start locating all the elements above and start checking them out as soon as I do later this week.
Basic causes for the failure are:
- fuses
- wires, ground
- connctors
- all side bolster elements shot (direct power) AND seat or backrest element shot (they are in series).
- adjuster module bad
- (if only the temperature sensors were bad, the side bolster would still warm up)
First: check if any of the elements heat up: side bolsters, seat, backrest (key on, adjuster wheel to various settings)Second: check if adjuster wheel lights up (mine doesn’t).
Considering that both seat heaters are not working and based on the wiring diagrams, I plan to attack the issue in the following way, referring to driver’s seat diagram/locations:
1. Check fuses S5 (assume main panel location) and S244 (fuse 44; in ‘fuse holder’, also assume main panel). This would be a most likely cause, but I had checked all fuses recently, therefore I have little hope that this is it.
2. The adjusters (E94) have built in bulbs (to illuminate the adjustment wheel). In my case, both lights are not working. Since they seem to be independent of anything else, this may be an additional pointer. All they have is ground 135 (0.5mm brown) and dimmed voltage from the instrument cluster combination processor J218 (0.35mm Grey/blue).
3. There are actually 3 heating elements per seat: seat, backrest, side bolster. If non of the 3 work, it points towards a problem ‘upstream’. So let’s look there first. They are getting their voltage from the T6r wire connector, 6 point, white, left A pillar, which are connected with 2 wires to the E94 (left)/E95 (right) adjuster. Let’s start there.
4. Take the adjusters out of the dash.
5. The diagram shows 7 connections/wires. Since I don’t have heated steering wheel or multifunction steering wheel, one is not used.
a. The grey/blue (6/58s) should show dimmable voltage with key on. Verify.
b. Check bulb at this time (mine are both not working). If dimmable voltage is present on 6/58s, then bulb is likely bad.
c. The black/red (5/15) should have switch power (from 5 amp fuse S5). Verify.
d. The red/white (1/30) one should have switch power (from 15 amp fuse S244 (number 44). Verify.
e. The brown (7/31) should be ground. Verify.
f. “4” should have nothing
g. Black/white “3” goes to the T6r white 6 point wire connector at left A pillar that connects to the temperature sensor G59 (monitors ONLY the sea (Z6) and backrest (Z7) temp, not the side bolsters (Z31). This is the ‘signal’ wire/voltage. Together with the position of the adjuster wheel (poti) and the temp sensor, it sends voltage to the heating elements and cuts voltage when selected temp is reached. Verify. If no voltage at any position of the adjuster wheel is present, the poti in the adjuster is bad.
h. “2” (black/yellow), thick 1.5mm, provides the heating power to the heating elements. The side bolsters get voltage when selector switch is moved out of zero position, bypassing the temperature sensor. Therefore, we should see battery voltage with key on and selector in 1-5 position. Verify. If all else above pans out, but no voltage on “2”, the transistor (?) in the adjuster is bad.
6. If the adjuster module E94 checks out, the problem is downstream.7. The green 6 point wire connector under the driver seat (T6t) can be checked for:
a. Black/white 0.5mm T6t/2 connects to the white 6 point connector “3” on the adjuster E94, see 5.g)
b. Black/yellow 1.5mm T6t/2 connects to the white 6 point connector “2” on the adjuster E94, see 5.h)
c. Brown/black 0.5mm T6t/1 should have ground.
d. Brown 1.5mm T6t/3 should have ground
8. If 7) pans out, its time to check the heating elements and the G59 temperature sensor 9) Since the side bolster elements Z31 are not temperature controlled, they can be checked directly (resistance), either directly on the elements or indirectly between green wire connector T6t/4 and T6t/3.
10. The temperature sensor G59 seems to have 4 connections is likely physically close to the seat heating element Z6 itself. 3 wires Black/White (0.5mm), Black/yellow (1.5mm), Brown/black (0.5mm) and a wire to the T2a double wire connector that connects the backrest heating element Z7.
11. Elements Z6 and Z7 are in series, so if one fails, both go out.
Chime in with any comments/corrections/photos/suggestions.
I currently don’t have access to the car. I will start locating all the elements above and start checking them out as soon as I do later this week.
#7
12-21-2010, 12:19 PM
Dash wheel removal
I need to remove the heated seat wheel from the dash, and are famous for braking the darn plastic tabs.
How do they come off without braking?
Bentley calls it 'adjuster for heated driver's seat'.
How do they come off without braking?
Bentley calls it 'adjuster for heated driver's seat'.
#8
12-21-2010, 01:15 PM
#9
04-03-2011, 05:28 PM
Yellow connector under seat
Does anyone know what the yellow connector under the front seats controls? The passenger side is yellow/brown and yellow/blue the drivers side is white/brown and white/blue. Both are not connected on my 98 A4 Avant.
#10
04-03-2011, 05:49 PM
Yellow are the airbag connectors. I finally got rid of the codes on my 98 but cutting the connectors our and solder/shrink tubing the wires together. Free length (by taking the connector out of its holder), zip tie, contact cleaner, etc. or anything else did not work.