Sub-Mode 4

In Sub-Mode 4, battery voltage is applied to the air mix door servo motor to rotate the air mix door back to the original position it was in before diagnostic mode M2 was selected. Once the door is in position, the total range of door movement will be computed according to the voltages that were previously measured. This range will be displayed in degrees on the set temperature digits as a number [1]. The normal operating range is between 45 and 75 degrees.
- If the range of travel is less that 45 degrees, check for a stuck air mix door, faulty servo motor, or a faulty potentiometer.
- If the air mix door moves but the voltage readings do not correspond with the door movement, check for a faulty potentiometer.


REMARKS:
[1] A "45 " displayed will equal 45 degrees total air mix door travel.