HVAC Controls, Manual Three Zone
HVAC Controls, Manual Three Zone
• The front HVAC control utilizes integrated circuitry and information carried on the controller area network IHS bus to monitor many sensors and switch inputs throughout the vehicle. In response to those inputs, the internal circuitry and programming of the HVAC control allows it to control the electronic functions and features of the MTC HVAC system.
• The front HVAC control is diagnosed using a scan tool.
• Prior to replacing an HVAC control, check for any diagnostic trouble codes related to the HVAC systems and run the calibration procedure to verify that the concern is not a system issue.
• The front HVAC control cannot be repaired and must be replaced if inoperative or damaged.
• Computer logic that remembers the settings of the controls when the ignition is turned off and retains those settings after a restart. If the system is off when the ignition is turned off it will be off when the engine is restarted, etc.
The front HVAC control for the manual temperature control dual zone front and rear HVAC system allows the driver and front and rear seat passengers the ability to regulate air temperature as well as fan speed for their individual zones. Operation of the rear controls can be locked out by the front HVAC control. All controls are identified by the graphic symbols.
1 Manual dual zone HVAC control
• The front manual dual zone HVAC control and integral computer is located in the instrument panel.
2 Rotary temperature control
• Temperature control to select the separate temperature for the driver comfort zone.
3 Button Mode Controls
• Five push button mode controls to select the position of the discharged air for the driver and front passenger comfort zones.
• An indicator lamp illuminates in each of the controls when selected.
4 Rotary front fan speed control
• Control knob for front fan speed selection and turning the HVAC system off.
5 Button Mode Controls
• Five push button mode controls to select the position of the discharged air for the driver and front passenger comfort zones.
• An indicator lamp illuminates in each of the controls when selected.
6 Air recirculation control
• Push button air recirculation control.
• An indicator lamp illuminates in the control when selected.
7 Rotary temperature control
• Temperature control to select the separate temperature for the front passenger comfort zone.
8 Rear window defogger
• Push button rear window defogger on/off control.
• The rear window defogger system operates and the indicator lamp illuminates in the control even when the HVAC system is turned off.
• An indicator lamp illuminates in the control when selected.
9 Heated seat control
• Push button front heated seat control.
• An indicator lamp illuminates in the control when selected.
10 Rotary temperature control
• Temperature control to select the separate temperature for the rear passenger comfort zone.
11 Rotary front fan speed control
• Rotary control knob for rear fan speed selection and turning the rear HVAC system off.
• This control has a position for locking out the rear HVAC controls, allowing only the driver and front seat passenger control of the rear HVAC system.
12 Heated seat control
• Push button front heated seat control.
• An indicator lamp illuminates in the control when selected.
13 A/C on/off control
• Push button A/C on/off control.
• An indicator lamp illuminates in the control when the A/C system is in operation.