B1918

DTC B1918

CIRCUIT DESCRIPTION
The heated seat mode and temperature switches are normal open. When the switch is pressed, its contacts are closed to ground signaling the door control module of the heated seat command. The door control module then sends a GMLAN message to the memory seat module (MSM) indicating the heated seat request. The MSM then sends a pulse width modulation (PWM) signal to the climate control seat module (CCSM) indicating the heated seat request. In response to this signal, the CCSM activates the requested heated seat mode.

DTC DESCRIPTORS
This diagnostic procedure supports the following DTCs:
DTC B1913: Seat Heater Switch 1 Circuit High
DTC B1918: Seat Heater Switch 2 Circuit High

CONDITIONS FOR RUNNING THE DTC
The door module must be powered and cannot have B1327 - Battery Voltage Low or B1328 - Battery Voltage High set as an active DTC for this DTC to set.

CONDITIONS FOR SETTING THE DTC
If the door module detects that a heated seat switch input circuit is active for 30 continuous seconds, the switch will be considered shorted and the DTC will set.

ACTION TAKEN WHEN THE DTC SETS
After the initial heated seat activation, no other heated seat switch activations shall be recognized as a result of this switch circuit being active.

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The DTC automatically clears when the switch circuit setting the DTC is no longer active.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 number below refers to the step number on the diagnostic table.
2. This step checks the existing state of the heated seat mode BACK ONLY switch by using the current state of the input parameter.