Circuit Description
The power lumbar switches are inputs to the driver seat module (DSM). The seat module supplies the switch assembly with a battery positive switch supply circuit and monitor the switch signal circuits. In an inactive state the switch signal circuits are floating and when a switch is pressed the signal circuit is closed to the switch power circuit within the lumbar switch assembly. When battery voltage is present on the switch signal circuit the seat module determines the switch status to be active.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B1830 Driver Seat Lumbar Forward Switch Circuit |
| • | DTC B1835 Driver Seat Lumbar Rearward Switch Circuit |
Conditions for Running the DTC
Battery voltage to the seat module must be within 7-16 volts.
Conditions for Setting the DTC
A switch signal circuit to the seat module is active for more than 60 seconds.
Action Taken When the DTC Sets
The seat module will disable the power lumbar function for which the DTC has set.
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 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 scan tool display Idle? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
3 | Disconnect the power lumbar switch connector. Does the scan tool display Idle? | Go to Step 5 | Go to Step 4 |
4 | Test the switch signal circuit for which the DTC has set for a short to voltage. Refer to Circuit Testing and to Wiring Repairs. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
5 | Inspect for poor connections at the power lumbar switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs. Did you find and correct the condition? | Go to Step 9 | Go to Step 6 |
6 | Replace the lumbar switch. Refer to Front Seat Lumbar Control Switch Replacement . Is the repair complete? | Go to Step 9 | -- |
7 | 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 9 | Go to Step 8 |
8 | Replace the seat module. Refer to Control Module References for replacement, setup, and programming. Is the repair complete? | Go to Step 9 | -- |
9 |
Does the DTC reset? | Go to Step 2 | System OK |
