When the RH side refreshing seat switch (seat heater switch) is operated, the air conditioning amplifier assembly receives the signal. The air conditioning amplifier assembly receives the signal and operates the RH side front seat heater.
If the battery voltage is low, the seat heater system may not operate. When "High Power Consumption Partial Limit on AC/Heater Operation" is displayed on the multi-information display in the combination meter assembly, inspect the battery, referring to On-vehicle Inspection for the charging system.
for M20C-FKS: Click herePower Source / Network>M20C-FKS (BATTERY / CHARGING)>CHARGING SYSTEM>ON-VEHICLE INSPECTION202409,999999,_57,_087045,_0418150,RM100000002NHRA,
for M20D-FKS: Click herePower Source / Network>M20D-FKS (BATTERY / CHARGING)>CHARGING SYSTEM>ON-VEHICLE INSPECTION202409,999999,_57,_083089,_0402337,RM100000002NHRF,
If the seat heater system is operated when the battery voltage is low, due to the electrical load limit control that gives voltage supply priority to the power steering system, the seat heater system may not operate. In this case, check the vehicle control history of the power steering system and check that "Battery Voltage Drop: X208F" is not stored before proceeding with troubleshooting.
Inspect the fuse related to this system before inspecting the suspected areas below.
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Body Electrical / Air Conditioner / Active Test.
Perform the Active Test according to the display on the GTS.
| Tester Display | Measurement Item | Control Range | Diagnostic Note |
|---|---|---|---|
| Front Right Seat Heater | RH side front seat heater operation | OFF/ON | - |
| Tester Display |
|---|
| Front Right Seat Heater |
RH side front seat heater operates normally.
| Proceed to |
|---|
| OK |
| NG |
OK
NG
Replace the refreshing seat switch (seat heater switch) with a new or known good one.
| Proceed to |
|---|
| NEXT |
NEXT
Check the RH side front seat heater operation.
RH side front seat heater operates normally.
| Proceed to |
|---|
| OK |
| NG |
OK
NG
| *a | Front view of wire harness connector
(to Seat Heater Control Sub-assembly RH) |
Disconnect the seat heater control sub-assembly RH connector.
Measure the voltage according to the value(s) in the table below.
| Tester Connection | Switch Condition | Specified Condition |
|---|---|---|
| S3-1 (B1) - Body ground | Engine switch on (IG) | 11 to 14 V |
| S3-1 (B1) - Body ground | Engine switch off | Below 1 V |
| Proceed to |
|---|
| OK |
| NG |
OK
NG
Disconnect the G48 air conditioning amplifier assembly connector.
Disconnect the S3 seat heater control sub-assembly RH connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| G48-12 (SM1R) - S3-5 (SWR) | Always | Below 1 Ω |
| G48-12 (SM1R) or S3-5 (SWR) - Other terminals and body ground | Always | 10 kΩ or higher |
| Proceed to |
|---|
| OK |
| NG |
OK
NG
Disconnect the S17 separate type front seat cushion cover RH (front seat cushion heater) connector.
Disconnect the S3 seat heater control sub-assembly RH connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| S17-6 - S3-10 (E1) | Always | Below 1 Ω |
| S17-6 or S3-10 (E1) - Other terminals and body ground | Always | 10 kΩ or higher |
| S17-1 - S3-7 (HIR) | Always | Below 1 Ω |
| S17-1 or S3-7 (HIR) - Other terminals and body ground | Always | 10 kΩ or higher |
| S17-2 - Body ground | Always | Below 1 Ω |
| Proceed to |
|---|
| OK |
| NG |
OK
NG
Remove the separate type front seat cushion cover RH (front seat cushion heater).
Inspect the separate type front seat cushion cover RH (front seat cushion heater).
| Proceed to |
|---|
| OK |
| NG |
OK
NG
Remove the separate type front seatback cover RH (front seatback heater).
Inspect the separate type front seatback cover RH (front seatback heater).
| Proceed to |
|---|
| OK |
| NG |
OK
NG
Replace the seat heater control sub-assembly RH with a new or known good one.
| Proceed to |
|---|
| NEXT |
NEXT
Check the RH side front seat heater operation.
RH side front seat heater operates normally.
| Proceed to |
|---|
| OK |
| NG |
OK
NG