A/C Control Blend Door Input Shorted To Battery (Manual A/C)
NOTE:
After making any repairs, perform BODY VERIFICATION TEST
under VERIFICATION TESTS.
Monitored & Set Condition
- When Monitored: With ignition on.
- Set Condition: The BCM detects an abnormally high voltage on its blend request input.
Possible Causes:
- Control Head - Short To Voltage
- Temperature Select CKT Shorted To Voltage
- Body Control Module - Temperature Select Short To Voltage
Testing
- With the scan tool, erase BODY CONTROL DTC's. Turn ignition off. Disconnect the manual temp control head C1 harness connector. See Figure . Turn ignition on. Measure the voltage of the temperature select circuit. If the voltage is .3 volt or more, go to next step. If the voltage is .3 volt or less, replace the control head. See MANUAL A/C-HEATER SYSTEMS - CONCORDE & INTREPID article in HVAC.
- Disconnect BCM C2 harness connector. See Figure . Turn ignition On. Measure the voltage of the temperature select circuit. If there is any voltage present, repair the temperature select circuit for a short to voltage. If no voltage is present, go to next step.
- If there are no possible causes remaining, replace the BCM. See BODY CONTROL MODULE under REMOVAL & INSTALLATION.