Without Scan Tool

To enter the "ACAC Diagnostic System Check," press the "TEMP " switch and the "OFF" switch on the control panel at the same time. Upon entry, a segment check will be performed and then the graphic display will show pointer number "-00". If the compressor clutch is being requested, the "EXT TEMP" graphics will be displayed. The "Blower Decrease" and "Blower Increase" switch can be used to increase and decrease the pointer number. The "MIDDLE" switch can be used to change from pointer -02 to DTC or parameter values for pointers "05-37"

To display HVAC DTCs, select pointer number "-02", and press the "MIDDLE" switch. At this time any current and history trouble codes will be displayed. A failure indicates that the control has detected an open, short to ground or faulty component in that circuit. While that failure is current, the H-A/C control will use a default value. When the graphic display is displaying numbers 200 to 299, they appear as numbers 100 through 199 with a "-" in front of them. For example, the value of 200 would be displayed as "-100".