GM Service Manual Online
For 1990-2009 cars only

The heated seat control module LO input terminal is momentarily grounded when the following conditions exist:

    • You press LO on the heated seat switch.
    • The ignition switch is in the RUN position.

When the heated seat control module is momentarily grounded, the heated seat control module turns on the heater in the seat. The heated seat control module monitors the seat surface temperature through a thermistor located in the center seat back. Select LO in order for the heated seat control module to remain at the seat surface temperature of approximately 37.5°C (98.5°F). The HI mode is similar to the LO mode. The HI mode allows the temperature to increase approximately 5 degrees. Press the OFF switch in order to momentarily ground the heated seat control module OFF input. The module will react by turning off the voltage that is applied to the seat heaters. The module will also turn off the heated seats whenever the ignition switch is turned OFF.