Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Electronic Manual Temperature Control (EMTC) System
The EMTC system heats or cools the vehicle depending on the HVAC module - EMTC control panel selection.
- The EMTC control panel selections determine heating or cooling, air distribution and enables blower motor operation.
- The temperature control setting determines the air temperature.
- The blower motor switch varies the blower motor speed.
- During A/C operation the system also reduces the relative humidity of the air.
The EMTC system operation is determined by the settings on the HVAC module - EMTC . The EMTC system is composed of the HVAC module - EMTC , blower motor resistor, mode door actuator, air inlet door actuator and temperature blend door actuator to control the various functions.
The blower motor switch:
- sets the blower motor speed.
- directs the blower motor path to ground through the blower motor resistor to allow blower motor operation in LO, MED-LO and MED-HI.
- directs the blower motor path directly to ground, bypassing the blower motor resistor, to allow blower motor operation in HI.
The A/C request button:
- can request the A/C compressor ON when the function selector switch is in PANEL, FLOOR/PANEL and FLOOR and when the A/C request switch is pressed. Indicator illuminates when A/C request switch is toggled ON.
- indicator illuminates when the function selector switch is in MAX A/C and cannot be toggled.
- indicator does not illuminate in OFF and cannot be toggled.
- indicator can be toggled ON or OFF in FLOOR/DEFROST and DEFROST. The A/C compressor will operate regardless of indicator status if the outside air temperature is above 6°C (43°F).
- is serviced only with the HVAC module - EMTC .
The function selector switch:
- selects airflow direction.
- is serviced only with the HVAC module - EMTC .
The temperature selector:
- selects fill WARM and full COOL as well as blended outlet temperatures.
- is serviced only with the HVAC module - EMTC .
The air recirculation button:
- selects either recirculated or outside air source.
- recirculates air in any mode except DEFROST, if requested.
- is disabled in MAX A/C or OFF mode where recirculated air only is used.
- is disabled in DEFROST mode where outside air only is used.
- is serviced only with the HVAC module - EMTC .
- my be a timed function in FLOOR/DEFROST and DEFROST.
The auxiliary climate controls:
- select the auxiliary blower motor speed.
- select the auxiliary airflow mode/temperature.
The HVAC module - EMTC also includes:
- a rear window defrost button, refer to GLASS, FRAMES AND MECHANISMS article.
- heated/cooled seat controls, refer to SEATING article.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.