B1845 (With RPO Code AM3)
CIRCUIT DESCRIPTIONWhen the power seat switches are pressed they send a 12 V signal to the Memory Seat Module (MSM). The MSM commands the driver seat 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The DTC automatically clears when the switch circuit setting the DTC is no longer active.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 1-5:
Steps 6-15:
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 (B+) in the lumbar down output circuit of the massage module.
15. This step verifies the repair
"For the description of RPO code(s) shown in this article or any of the images therein, refer to the RPO code list found at the Vehicle/Application And ID." RPO Codes