B1845 (With RPO Code AM3)

DTC B1845 (WITH RPO CODE AM3)

CIRCUIT DESCRIPTION
When the lumbar switches are pressed they send a 12 volt signal through the switch signal circuits to the memory seat module (MSM). The MSM commands the lumbar support to move in response to the switch inputs.

CONDITIONS FOR RUNNING THE DTC
- The MSM must be powered.
- DTC B1327 - Battery Voltage Low can not be current.

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.

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The DTC automatically clears when the switch circuit setting the DTC is no longer active.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

Steps 1-2:

Steps 3-7:

Steps 8-14:

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 seat switch parameters display active, possibly one of the lumbar switch signal circuits is shorted to voltage.
4. When the seat switch is disconnected, this step determines if the lumbar switch contacts are stuck closed or if one of the switch signal circuits is possibly shorted to voltage.
7. Determines if there is a short to battery positive voltage in the lumbar down output circuit of the massage module.
15. This step verifies the repair.