Circuit Description
The driver seat module (DSM) controls the voltage supply and the ground circuits to the seat heater elements. When a heated seat function is commanded active, the seat module will switch battery voltage to the heater element supply circuits, and ground is provided through low side drive control circuits. During heated seat operation both the seat back and cushion heater elements are supplied battery voltage. The seat module grounds the appropriate control circuits for back only or back and cushion heating modes, and opens or closes the active control circuits as necessary in order to maintain the desired seat temperature.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B2425 Driver Seat Heater Circuit |
| • | DTC B2430 Passenger Seat Heater Circuit |
Conditions for Running the DTC
| • | Battery voltage to the seat module must be within 7-16 volts. |
| • | Heated seat operation is attempted. |
Conditions for Setting the DTC
| • | One of the low side drive control circuits is shorted to voltage or ground. |
| • | One of the heater element voltage supply circuits is shorted to voltage or ground. |
Action Taken When the DTC Sets
The seat module will disable heated seat operation.
Conditions for Clearing the DTC
| • | The DTC will be stored as a history code when the fault is no longer present. |
| • | A history DTC will be cleared after completing 100 consecutive ignition cycles. |
Diagnostic Aids
If the DTC is only found in history, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Driver Seat Schematics and Passenger Seat Schematics Connector End View Reference: Power Seat Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Does the heated seat system operate normally? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
3 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 4 |
4 | Connect a test lamp from the seat back heater element control circuit terminal in the harness connector C4 to ground. Does the test lamp illuminate? | Go to Step 8 | Go to Step 5 |
5 | Connect a test lamp from battery voltage to the seat cushion heater element control circuit terminal in the harness connector C4. Does the test lamp illuminate? | Go to Step 9 | Go to Step 6 |
6 | Connect a test lamp from battery voltage to the seat back heater element control circuit terminal in the harness connector C4. Does the test lamp illuminate? | Go to Step 10 | Go to Step 11 |
7 | Repair the seat cushion heater element voltage supply or ground circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs. Is the repair complete? | Go to Step 13 | -- |
8 | Repair the seat back heater element voltage supply or ground circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs. Is the repair complete? | Go to Step 13 | -- |
9 | Repair the seat cushion heater element voltage supply or ground circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs. Is the repair complete? | Go to Step 13 | -- |
10 | Repair the seat back heater element voltage supply or ground circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs. Is the repair complete? | Go to Step 13 | -- |
11 | Inspect for poor connections at the seat module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs . Did you find and correct the condition? | Go to Step 13 | Go to Step 12 |
12 | Replace the seat module. Refer to Control Module References for replacement, setup, and programming. Is the repair complete? | Go to Step 13 | -- |
13 |
Does the DTC reset? | Go to Step 2 | System OK |
