Running the Auto AC self-test
Thanks to Scott Patterson for this self test procedure for the AC controls :
ELECTRONIC CLIMATE CONTROL - SELF DIAGNOSTIC TEST
The control assembly will detect electrical malfunctions occurring during the self test. 1. Make sure the coolant temperature is at least 120F (49C).
2. To display error codes, push the OFF and FLOOR buttons simultaneously and then the AUTOMATIC button within 2 seconds. The test may run as long as 20 seconds, during which time the display will be blank. If the display is blank for more than 20 seconds, consult the No Error Code Found Diagnosis and Testing chart.
3. The Self Diagnostic Test can be initiated at any time with the resulting error codes being displayed. Normal operation of the system stops when the Self Diagnostic Test is activated. To exit the self test and restart the system, push the COOLER button. The self test should be deactivated before powering the system down.
ERROR CODE KEY
1.. Replace control head
2.. Blend door problem
3.. In-car temp sensor open or short
4.. Ambient temp sensor open or short
5.. Sunload sensor short
6.. 888 Test complete - no failures (all segments on)