Heated Seat Inoperative Driver
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Driver Seat Schematics Connector End View Reference: Power Seat Connector End Views | ||||
1 | Did you review the Heated Seat System Description and Operation and perform the necessary inspections? | -- | Go to Step 2 | Go to Symptoms - Seats |
2 |
Does the heated seat system operate normal? | -- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
3 | Do the low and high switch indicators operate normal? | -- | Go to Step 6 | Go to Step 4 |
4 |
Does the test lamp illuminate? | -- | Go to Step 5 | Go to Step 11 |
5 | Connect a test lamp from the ignition voltage supply circuit terminal to the ground circuit terminal in the heated seat switch harness connector. Does the test lamp illuminate? | -- | Go to Step 15 | Go to Step 12 |
6 |
Does the test lamp illuminate? | -- | Go to Step 7 | Go to Step 13 |
7 | Connect a test lamp from the battery voltage supply circuit terminal to the ground circuit terminal in the C319 seat harness connector. Does the test lamp illuminate? | -- | Go to Step 8 | Go to Step 14 |
8 |
Is the resistance at or near the specified values? | Hi 2.5K ohms Lo 4.9K ohms | Go to Step 10 | Go to Step 9 |
9 |
Did you find and correct the condition? | -- | Go to Step 21 | Go to Step 15 |
10 |
Is the resistance within the specified values? | 0.5-2 ohms | Go to Step 16 | Go to Step 17 |
11 | Repair the open or short to ground in the ignition voltage supply circuit to the heated seat switch. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 21 | -- |
12 | Repair the open or high resistance in heated seat switch ground circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 21 | -- |
13 | Repair the open or short to ground in the battery voltage supply circuit to the heated seat control module. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 21 | -- |
14 | Repair the open or high resistance in the heated seat control module ground circuit. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 21 | -- |
15 | Inspect for poor connections at the heated seat switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 21 | Go to Step 18 |
16 | Inspect for poor connections at the seat cushion heater element. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 21 | Go to Step 19 |
17 | Inspect for poor connections at the seat back heater element. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 21 | Go to Step 20 |
18 | Replace the heated seat switch. Refer to Lumbar Switch Replacement . Is the repair complete? | -- | Go to Step 21 | -- |
19 | Replace the seat cushion heater element. Refer to Driver Seat and Passenger Seat Cushion Heater Replacement . Is the repair complete? | -- | Go to Step 21 | -- |
20 | Replace the seat back heater element. Refer to Driver Seat and Passenger Seat Back Cushion Heater Replacement . Is the repair complete? | -- | Go to Step 21 | -- |
21 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 3 |
Heated Seat Inoperative Passenger
Circuit/System Description
The heated seat module controls the heated seat elements based on an input from the heated seat switch. B+ is applied to the heated seat module through the HTD/SEAT fuse. With the heated seat switch in the LOW or HIGH position, a voltage signal is sent to the heated sweat module. Based on this voltage signal, the heated seat module will apply a specific voltage to the seat back and seat cushion elements, causing them to warm. A thermistor located in the seat cushion element prevents the elements from becoming too hot.
Diagnostic Aids
The passenger heated seat will only operate when the passenger seatbelt is buckled.
Reference Information
Schematic Reference
Connector End View Reference
Power Seat Connector End Views
Description and Operation
Heated Seats Description and Operation
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
- Ignition ON, observe the scan tool Passenger Seat Belt Switch parameter while buckling and unbuckling the passenger seat belt. The reading should change between Buckled and Unbuckled.
- With the passenger seat belt buckled, place the heated seat switch in the HIGH or LOW position. The heated seat should begin to warm.
| ⇒ | If the reading does not change between the specified values, refer to Seat Belt Indicator Circuit Malfunction. |
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the passenger heated seat switch.
- Ignition ON, verify that a test lamp does not illuminates between the signal circuit terminal B and ground.
- Ignition OFF, test for less than 1.0 ohm of resistance between the ground circuit terminal E and ground.
- Ignition ON, verify a test lamp illuminates between the ignition circuit terminal C and ground.
- Connect the harness connector at the passenger heated seat switch.
- Disconnect the harness connector C318.
- Ignition OFF, test for less than 1.0 ohm of resistance between the ground circuit terminal B and ground.
- Ignition ON, verify a test lamp illuminates between the B+ circuit terminal A and ground.
- With the passenger seat belt buckled and the heated seat switch in the LOW position, test for B+ at the control circuit terminal C.
- With the passenger seat belt buckled and the heated seat switch in the HIGH position, test for B+ at the control circuit terminal C.
- Reconnect the harness connector C318.
- Disconnect the harness connector at the heated seat cushion element.
- Ignition OFF, test for less than 1.0 ohm of resistance between the thermistor ground circuit terminal and ground.
- gnition ON, with the passenger seat belt buckled and the heated seat switch in the HIGH position, verify that a test lamp illuminates between the thermistor control circuit terminal and ground.
- With the passenger seat belt buckled and the heated seat switch in the HIGH position, verify that a test lamp illuminates between the cushion element control circuit terminal and ground.
- Reconnect the harness connector at the seat cushion element.
- Disconnect the harness connector at the seat back element.
- Ignition OFF, test for less than 1.0 ohm of resistance between the ground circuit terminal A and ground.
- Ignition ON, with the passenger seat belt buckled and the heated seat switch in the HIGH position, test for B+ between the control circuit terminal B and ground.
- If all circuits test normal, test or replace the heated seat back element.
| ⇒ | If the test lamp illuminates, test the signal circuit for a short to voltage. |
| ⇒ | If greater than the specified value, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. |
| ⇒ | If greater than the specified value, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
| ⇒ | If not the specified value, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the passenger heated seat switch. |
| ⇒ | If not the specified value, test or replace the passenger heated seat switch. |
| ⇒ | If greater than the specified value, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If all circuits test normal, replace the heated seat module. |
| ⇒ | If greater than the specified value, test the ground circuit for an open/high resistance. |
| ⇒ | If less than the specified value, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the heated seat cushion element. |
Repair Instructions
