Manual A/C System Test

Possible Causes:

• Manual A/C System Test

Testing

• Ensure there is vehicle communication with the BCM and the PCM before proceeding. If not, see DIAGNOSTIC TROUBLE CODE IDENTIFICATION  or SYMPTOM IDENTIFICATION  tables for related symptoms.
• With the scan tool, read engine DTC's. If any climate control related DTC's are present, see DIAGNOSTIC TROUBLE CODE IDENTIFICATION  or SYMPTOM IDENTIFICATION  tables for related symptoms.
• With the scan tool, read the body DTC's. If any climate control related codes are present, continue with testing. If no codes are present, recalibrate the doors and recheck the system. See MANUAL A/C-HEATER SYSTEMS - CONCORDE & INTREPID article in HVAC.
• Record and erase the code(s). Turn the blower ON, set the temperature control at mid position, start engine and with the scan tool read DTC's. If no code appears, slowly turn the temperature control from cold to hot, then back to cold while observing the scan tool. If a code appears, perform appropriate test. See DIAGNOSTIC TROUBLE CODE IDENTIFICATION  table.
• If a code still does not appear, turn the mode switch to each position, waiting 20 seconds between each one. Momentarily press the A/C and rear defogger buttons. Upon seeing the first code appear, stop and perform the appropriate test.
• If multiple codes appear, repair any that relate to a short circuit first. If a short to battery code is set, all 4 output shorted to battery codes will appear. It will then be necessary to isolate each circuit to determine which is at fault.
• If DTC's have appeared, see DIAGNOSTIC TROUBLE CODE IDENTIFICATION  table. If no codes have appeared, recalibrate the doors, reset the BCM and recheck the climate control system performance. See MANUAL A/C-HEATER SYSTEMS - CONCORDE & INTREPID article in HVAC.