B1845

DTC B1830, B1835, B1840 or B1845

Circuit Description

When the power seat switches are pressed they send a 12-volt signal to the memory seat module (MSM). The MSM commands the driver seat to move in response to the switch inputs.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

* DTC B1830 Seat Lumbar Forward Switch Circuit
* DTC B1835 Seat Lumbar Rearward Switch Circuit
* DTC B1840 Seat Lumbar Up Switch Circuit
* DTC B1845 Seat Lumbar Down Switch Circuit

Conditions for Running the DTC

The MSM must be powered and can not have DTC B1327 - Device Power 1 Circuit Low as an active DTC for this DTC to set.

Conditions for Setting the DTC

* If a seat switch circuit continues to be active for 30 seconds after a motor controlled by that switch reaches the end of its travel, the switch will be considered shorted and the MSM will set the DTC.
* If a position sensor DTC is current and the associated switch is active for 30 continuous seconds, the switch will be considered shorted and the MSM will set a switch DTC.
* A switch DTC will not set if DTC B1327 is current.

Action Taken When the DTC Sets

* A motor output driven in response to a switch considered failed, is deactivated for both directions.
* All memory recall commands are ignored.
* The MSM will respond to any other switch input that has not set a DTC.

Conditions for Clearing the DTC

The DTC automatically clears when the switch circuit setting the DTC is no longer active.

Test Description

Step 1 - Step 10:

The numbers below refer to the step numbers on the diagnostic table.
2. Checks the existing state of the driver's seat lumbar switch by using the current state of the input parameter. If all of the lumbar switch parameters display active, possibly one of the lumbar switch signal circuits is shorted to voltage.
4. When the lumbar switch is disconnected, this step determines if the switch contacts are stuck closed, or if one of the switch signal circuits is possibly shorted to voltage.
10. This step verifies the repair.