B105C - Recirculation Door Travel Range Too Small: Notes

For a complete wiring diagram, refer to appropriate SYSTEM WIRING DIAGRAMS information.

Theory of Operation 

The A/C heater control calibrates each actuator individually. Automatic calibration occurs upon power up after installing a new A/C heater control. Manual calibration occurs by sending a command with the scan tool. The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C heater control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the measured calibration value is less than the expected range for this actuator, this DTC will set. Note that the control clears all stored calibration faults at the beginning of the calibration procedure.

• >>When Monitored:<< During actuator calibration.
• >>Set Condition:<< If the total span of the recirculation door is less than the low range limit.