Use the Scan Tool Data Display Values and Definitions Information
in order to assist in diagnosing the electronic climate control (ECC) module
problems. Compare the vehicles actual scan tool data with the typical
data display value table information. Use the data information in
order to aid in understanding the nature of the problem when the vehicle
does not match with the typical data display values.
The scan tool data values were taken from a known good vehicle under
the following conditions:
• | The ignition switch is in the ON position. |
• | The engine is running at idle. |
• | The vehicle is in PARK. |
• | The windows are closed. |
• | The ambient air temperatures are at 22-27°C (70-80°F). |
The Outside Air Temperature (OAT) (Range: -40-80°C/-40-176°F): This data refers to the outside air temperature (C/F) measured
at the outside air temperature (OAT) sensor by the electronic climate control
(ECC) module. In order for this temperature data to update the electronic
climate control (ECC) module must receive a vehicle speed input via
the class 2 serial data line.
The Inside Air Temperature (Range: -40-80°C/-40-176°F): This data refers to the inside air temperature (C/F) measured at
the inside air temperature sensor by the electronic climate control (ECC)
module.
The A/C (Upper) Outlet Temperature (Range: -40-80°C/-40-176°F): This data refers to the discharged air temperature at the upper
outlet.
The Heater (Lower) Outlet Temperature (Range: -40-80°C/-40-176°F): This data refers to the discharged air temperature at the lower
outlet.
The Solar Load Sensor (Range: 0-255 Counts): This data refers to the amount of the heat load generated by the
sunlight measured by the sun load sensor. If the sunlight heat load is high
the display will show 100-200. Approximately 230 counts
are displayed when the sunlight heat load is minimum.
The Mix Door Position (Range: 0-256 Counts): This data refers to the maximum position of the air mix valve.
The Air Mix Door Commanded (Range: 0-256 Counts): This data refers to the commanded air mix valve position driven
by the electronic climate control (ECC) module.
The Air Mix Actual (Range: 0-256 Counts): This data refers to the actual air mix valve position monitored
via the feedback line (CKT 733) to the electronic climate control (ECC)
module.
The Mix Door Minimum Position (Range: 0-256 Counts): This data refers to the minimum position.
The Blower Motor PWM Speed (Range: 0-100%): This data refers to the blower motor fan speed. Zero (0) is displayed
when the blower motor is OFF. The blower motor at the maximum speed will display
96-99%.
The Mode Selection Position Upper (Display: Auto/Upper Outlet/Bi-Level/Floor/Defog/Defrost): This data refers to the position of the mode selection knob and
the direction of the discharge air flow through the floor, instrument panel
and windshield defroster outlet vents. The positions are displayed
as follows:
• | AUTO -- The electronic climate control (ECC) module control
the discharge of air flow through the heater and A/C control system. |
• | UPPER OUTLET -- The air is flowing out the 4 upper outlets. |
• | BI-LEVEL -- The air is flowing out the 4 panel vents and
the 2 floor vents. |
• | FLOOR -- The air is flowing out the 2 floor vents. |
• | DEFOG -- The air is flowing out the defrost vent at the top
of the instrument panel. |
• | DEFROST -- The air is flowing out the defrost vent at the
top of the instrument panel. |
The A/C Request (Display: Yes/No): This data refers to the operation of the A/C compressor clutch
message from the electronic climate control (ECC) module to the VCM/PCM. The
scan tool sends a message to the VCM/PCM in order to turn the A/C compressor
clutch on. This message does not affect the state of the A/C LED on
the electronic climate control (ECC) module.
The A/C LED On (Display: On/Off): This data refers to the illumination of the A/C push button switch
LED (Light Emitting Diode). The LED is mounted in the A/C push-button switch
is ON when the A/C push-button is pressed indicating that the air conditioning
is being requested. Pressing the A/C push-button while the LED is ON
will turn the LED OFF and signal the electronic climate control (ECC)
module that the air conditioning is not requested.
The Rear Defogger Switch (Display: On/Off): This data refers to the illumination of the rear defogger push-button
switch LED. The LED mounted in the rear defogger switch is ON when the rear
defogger button is pressed in order to indicate that the rear defogger
is being requested. Pressing the rear defogger push-button while the
LED is ON will turn the LED OFF and signal the electronic climate
control (ECC) that the rear defogger is not requested.