Diagnostic Manual, Body and Accessories,
Volume 4.1
Diagnosis - Complaint Related Diagnostic Chart
| Complaint/Problem |
Possible cause |
Test step/Remedy 1) |
| Entire rear seat heater does not
operate. |
Rear HS control module (N25/6), voltage
supply. |
23  1.0 |
| Left rear seat cushion and backrest
heating does not operate. |
Rear HS control module (N25/6), voltage
supply.
Left rear seat heater switch (S51/3).
Left rear seat cushion heater element (R13/5) and left rear backrest heater
element (R13/6).
|
23 1.0
23
3.0
23
4.0 |
| Right rear seat cushion and backrest
heating does not operate. |
Rear HS control module (N25/6), voltage
supply.
Right rear seat heater switch (S51/4).
Right rear seat cushion heater element (R13/7) and right rear backrest heater
element (R13/8).
|
23 1.0
23
9.0
23
5.0 |
Indicator lamps in left rear seat
heater switch (S51/3) or right rear seat heater switch (S51/4) not operating.
Seat heater operates.
|
S51/3 indicator lamps.
S51/4 indicator lamps. |
23 7.0
23
12.0 |
Dimming of indicator lamps in left
rear seat heater switch (S51/3) or right rear seat heater switch (S51/4)
not operating.
|
S51/3 dimming.
S51/4 dimming. |
23 2.0, 8.0
23
2.0, 13.0 |
Illumination in left rear seat heater
switch (S51/3) or right rear seat heater switch (S51/4) not operating.
|
S51/3 illumination.
S51/4 illumination. |
23 6.0
23
10.0 |
Seat heating switches off with ignition:
OFF
When ignition is turned on again, the seat heaters are not switched
ON.
|
Rear HS control module (N25/6), voltage
supply. |
23 1.0 |
Only with 8 or 12 cylinder engines
CTP (idle) RPM does not increase with seat heaters in
stage II |
Left rear seat heater switch (S51/3),
Right rear seat heater switch (S51/4),
CTP (idle) RPM increase with seat heater switch in
stage II.
|
23 3.0
23
9.0
23
11.0 |
| 1) Observe Preparation
for Test, see 22. |
|
Printable
version
