If wiper and intermittent LEDs are flashing simultaneously, perform calibration test.
If wiper and intermittent LEDs are flashing alternately, level one codes are present. Wiper LED indicates display level. Each time wash button is pressed, display will cycle to next level.
One flash indicates fail codes. A 2-flash sequence indicates mode potentiometer test. A 3-flash sequence indicates blend potentiometer test. Intermittent LED indicates failure code (level 1) or potentiometer position (level 2 or 3). See FAILURE CODE VALUES table.
Temperature and mode potentiometers can be tested after calibration is complete by pressing wash button and cycling to level 2 or 3 as displayed by wiper LED. Press wash button once, wiper LED will begin a 2-flash sequence. Move mode selector switch from panel to defrost. Intermittent LED flash rate should decrease. Move mode selector switch from defrost to panel. Intermittent LED flash rate should increase.
Press wash button again, wiper LED will begin a 3-flash sequence. Move temperature selector lever from cold to hot. Intermittent LED flash rate should increase. Move temperature selector lever from hot to cold. Intermittent LED flash rate should decrease.
0Passed All Tests
1Mode Actuator Did Not Reach Defrost Position
2Mode Actuator Did Not Reach Panel Position
3Blend Actuator Did Not Reach Cold Stop
4Blend Actuator Did Not Reach Heat Stop
9Control Head Internal Failure
NOTE:Whenever heater control panel, heater unit, doors or door actuators are replaced, actuator calibration/diagnostics test must be performed.
Mode and blend door calibration compensates for mechanical differences in actuators, heater unit and its linkages. In-vehicle calibration is entered using switches and buttons on Heat Vent Air Conditioner (HVAC) front panel. If rear wiper and intermittent LEDs flash simultaneously when ignition is turned on, actuators have not been calibrated or a previous calibration failure occurred. Diagnostics will always occur during calibration.
To enter calibration/diagnostics test, set parking brake. Start and warm engine to normal operating temperature. With engine idling, turn blower switch to high. Turn mode switch to panel (air comes from instrument panel outlets). Move temperature lever to full cold. Press and hold rear wash and wiper buttons for 5 seconds (until all LEDs illuminate). Rear wiper and intermittent button LEDs will flash alternately during calibration test.
After approximately 60 seconds, if only wiper button LED is flashing, calibration is successful and system is okay.
To exit calibration/diagnostics test at any time, press rear wiper button or cycle ignition off and then on. Test will automatically terminate 15 minutes after calibration/diagnostics is entered.
Sunday, May 9th, 2010 AT 8:01 PM