B1918

Diagnostic Chart:

^ Refer to LH Front Heated Seat Schematics
^ Refer to RH Front Heated Seat Schematics
^ Refer to LH Rear Heated Seat Schematics
^ Refer to RH Rear Heated Seats Schematics

CIRCUIT DESCRIPTION
The heated seat temperature switch is normally open. When the temperature switch is pressed, it momentarily switches a battery positive voltage (B+) to the temperature input of the door module. The door module then momentarily grounds the temperature input of the heated seat module. The heated seat module examines the input to determine the change in the heated seat temperature setting.

CONDITIONS FOR RUNNING THE DTC
The door module must be powered and can not have B1328-Battery Voltage High or B1327-Battery Voltage Low 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 shorted to battery positive (B+) for 30 continuous seconds, the switch will be considered shorted and the DTC will set.

ACTION TAKEN WHEN DTC SETS
After the initial heated seat activation, no other heated seat switch activations shall be recognized as a result of this switch input staying active (shorted to voltage).

CONDITIONS FOR CLEARING THE DTC
The DTC automatically clears when the switch circuit setting the DTC is no longer active.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. Checks the existing state of the heated seat Heat/OFF switch by using the current state of the input parameter.