Pinpoint Test N : The Air Conditioning (A/C) Is Always On - A/C Mode Always Commanded On
WARNING: This page is about a different car, the 2015 Lincoln MKT. However, it is still accessible from the selected car via links, so may be relevant.
- N1 CHECK THE A/C SWITCH STATUS (CC_SW_AC) PID WITH THE A/C OFF
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - FCIM.
- Monitor the CC_SW_AC FCIM PID
- Select PANEL, press and release the A/C button (indicator off) on the HVAC controls.
Does the PID read Active when pressed and Inactive when released?
Yes GO to N2. No For 8 Inch (203mm) Touchscreen, 10 Speakers, REFER to Information and Entertainment Systems - 8-Inch (203 mm) Touchscreen, 8 Speakers Symptom Chart. For THX, 8 Inch (203mm) Touchscreen, 14 Speakers, REFER to Information and Entertainment Systems - THX® 8-Inch (203 mm) Touchscreen, 14 Speakers Symptom Chart. - N2 CHECK THE AIR CONDITIONING REQUEST SIGNAL (AC_REQ) PID WITH THE A/C OFF
- Enter the following diagnostic mode on the scan tool: DataLogger - PCM.
- Deactivate the A/C using the HVAC controls.
- Monitor the AC_REQ PCM PID
Does the PID read OFF?
Yes GO to N4. No GO to N3. - N3 CHECK THE AIR CONDITIONING REQUEST SIGNAL (AC_REQ) PID WITH HVAC MODULE DISCONNECTED
- Ignition OFF.
- Disconnect: HVAC Module - DATC C228A .
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - PCM.
- Monitor the AC_REQ PCM PID
Does the AC_REQ PCM PID read OFF?
Yes GO to N4. No GO to N5. - N4 CHECK FOR CORRECT HVAC MODULE OPERATION
- Ignition OFF.
- Disconnect and inspect all HVAC module connectors.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
- Connect all HVAC module connectors. Make sure they seat and latch correctly.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no TSB addresses this concern, INSTALL a new HVAC module. REFER to Climate Control . No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues. - N5 CHECK FOR CORRECT PCM OPERATION
- Ignition OFF.
- Disconnect and inspect all PCM connectors.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
- Connect all PCM connectors. Make sure they seat and latch correctly.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no TSB addresses this concern, INSTALL a new PCM. REFER to Electronic Engine Controls . No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.