Sub-Mode 1

Diagnostic Mode M2 has four sub-modes. The sub-modes are indicated by the display module segments:
sub-mode 1 BI-LEVEL
sub-mode 2 VENT
sub-mode 3 HEAT
sub-mode 4 HEAT/DEF
Voltage is applied to the air mix door servo motor by the Air Control Module to try to move the air mix door.

In Sub-Mode 1, the amount of voltage applied is in accordance with the preset temperature setting. While the air mix door is moving, the mode light will flash. When it stops flashing, the feedback voltage from the potentiometer on the air mix door will be displayed on the temperature digits [1]. Proper operating voltage output range is from 1.3 volts (full hot) to 4.0 volts (full cold).

NOTE: If the air mix door feedback circuit is either open or shorted to ground:
- The air mix door will not move.
- The four sub-modes cannot be performed.
- The display`s mode indicators will all remain unlit.
- The temperature digits will show "?".

Advance to sub-mode 2 by pressing the select switch right arrow once.


REMARKS
[1] There is no decimal point on this display. Example: 3.9 volts will be displayed as "39".