billw6560 Posted March 1 Report Share Posted March 1 Yesterday, the A/C was working fine, went to the car wash and went home. A few hours later, the wife took car, and mentioned that the car was only putting out heat. She also noticed that the outside temperature reading was minus -40. I also used to have a 2010 Fusion that had the same issue. Here, the A/C Evap sensor was bad (open), which was located under the dash. What a PITA! The $64,000 question is, as this appears to also be an open sensor, where is this located? I've seen very little on Google and YouTube, but it appears that it may be located under the front grill. I'm hoping this is the case, because I don't want to go dashboard diving again. Hope you folks can help. Thanks, Bill Quote Link to comment Share on other sites More sharing options...
Haz Posted March 2 Report Share Posted March 2 (edited) Welcome to the Forum, billw6560 ! From the 2018 Edge Workshop Manual... Placing your device cursor over underlined acronyms may yield their full-words description. Outside Air Temperature The Ambient Air Temperature (AAT) sensor is hardwired to the PCM through separate input and return circuits. The PCM provides a reference voltage to the Ambient Air Temperature (AAT) sensor and monitors the change in voltage resulting from changes in resistance as determined by outside air temperature. The PCM sends the ambient air temperature data to the GWM through the HS-CAN1 . The GWM sends the ambient air temperature message to the HVAC (part of the FCIM ) over the MS-CAN . The FCIM filters the data and sends the ambient air temperature filtered data back to the GWM over the MS-CAN . The GWM sends the ambient air temperature filtered message to the IPC over the HS-CAN3. The FCIM is programmed to update the messaged outside temperature data at different rates depending on several criteria to prevent false temperature displays due to a condition known as heat soaking. Heat soaking is where the outside air temperature is hotter in the location of the Ambient Air Temperature (AAT) sensor than the actual outside air temperature. The outside air temperature display update strategy requires a starting temperature to update from. This starting temperature is controlled based on the length of time the engine is off and the engine temperature. When the engine has been off for longer than 6 hours, the update strategy begins with the unfiltered ambient air temperature input to the PCM . If the engine has been off for less than 6 hours, and the engine coolant temperature is less than 49° C (120° F), the update strategy begins with the filtered ambient air temperature equal to the unfiltered ambient air temperature. If the engine has been off for less than 6 hours, and the engine coolant temperature is greater than 49° C (120° F), the update strategy begins at the stored previous outside air temperature value. When the sensed outside temperature rises and the vehicle speed is above 33 km/h (21 mph), the outside air temperature display updates after approximately 90 seconds. As the vehicle speed increases, the outside air temperature display updates at a faster rate that is proportional to the increase in vehicle speed. Once the vehicle speeds exceeds 81 km/h (50 mph), the display updates without any delay. If the vehicle speed drops below 33 km/h (21 mph), the update delays reset. When the sensed outside temperature drops, the display updates more quickly following the drop experienced by the Ambient Air Temperature (AAT) sensor. The Outside Air Temperature Display Is Inoperative or Incorrect Normal Operation and Fault Conditions If the air ambient temperature message is missing or invalid for less than 5 seconds, the IPC defaults the outside air temperature display to the last temperature reading, based upon the last message received. If the air ambient temperature message is missing or invalid for 5 seconds or longer from the PCM , the IPC displays all dashes (- - ) in the outside air temperature display area. Possible Sources Communication concern Ambient Air Temperature (AAT) sensor input to the PCM GWM concern FCIM concern PINPOINT TEST AE: THE OUTSIDE AIR TEMPERATURE DISPLAY IS INOPERATIVE OR INCORRECT AE1 PERFORM THE IPC (INSTRUMENT PANEL CLUSTER) SELF-TEST Ignition ON. Using a diagnostic scan tool, perform the IPC self-test. Are any Diagnostic Trouble Codes (DTCs) recorded? Yes REFER to DTC Chart: IPC in this section. No GO to AE2 AE2 PERFORM THE FCIM (FRONT CONTROLS INTERFACE MODULE) SELF-TEST Using a diagnostic scan tool, perform the FCIM module self-test. Are any Diagnostic Trouble Codes (DTCs) recorded? Yes Refer to the appropriate section in Group 415 for the procedure. No GO to AE3 AE3 CHECK THE GWM (GATEWAY MODULE A) DIAGNOSTIC TROUBLE CODES (DTCS) Using a diagnostic scan tool, check the GWM Continuous Memory Diagnostic Trouble Codes (DTCs). Are any Diagnostic Trouble Codes (DTCs) recorded? Yes REFER to: Communications Network (418-00 Module Communications Network, Diagnosis and Testing). No GO to AE4 AE4 PERFORM THE PCM (POWERTRAIN CONTROL MODULE) SELF-TEST Using a diagnostic scan tool, perform the PCM self-test. Are any Diagnostic Trouble Codes (DTCs) recorded? Yes REFER to the appropriate 303-14 section. No GO to AE5 AE5 CHECK THE OUTSIDE AIR TEMPERATURE CONCERN Verify the customer outside air temperature display concern. Is the outside air temperature display concern for an incorrect temperature display? Yes GO to AE6 No VIN required to access Guided Routine (IPC) AE6 CHECK THE AMBIENT AIR TEMPERATURE INPUT TO THE PCM (POWERTRAIN CONTROL MODULE) Using an infrared temperature scanner or similar tool, measure and record the temperature of the ambient air temperature sensor body. Ignition ON. Using a diagnostic scan tool, view the PCM Parameter Identifications (PIDs). Select the ambient air temperature PID (AAT). Monitor the ambient air temperature PID and compare PID value with the recorded temperature of the ambient air temperature sensor body. Does the ambient air temperature PID match the recorded ambient air temperature sensor measurement within +/- 3° C (+/- 5° F)? Yes GO to AE7 No GO to AE8 AE7 CHECK THE OUTSIDE AIR TEMPERATURE DISPLAY UPDATE Drive the vehicle above 33 km/h (20 mph) to allow the outside air temperature display to update. Did the outside air temperature display update toward the actual ambient air temperature? Yes The system is operating correctly at this time. Explain to the customer the operation of the system as it relates to the update strategy. No VIN required to access Guided Routine (FCIM) . AE8 CHECK THE AMBIENT AIR TEMPERATURE SENSOR RESISTANCE Ignition OFF. Disconnect PCM C1381B (2.0L Engine). Disconnect PCM C1551B (2.7L Engine). Disconnect PCM C175B (3.5L Engine). Measure: 2.0L Engine Positive Lead Measurement / Action Negative Lead C1381B Pin 51 C1381B Pin 18 2.7L Engine Positive Lead Measurement / Action Negative Lead C1551B Pin 51 C1551B Pin 18 3.7L Engine Positive Lead Measurement / Action Negative Lead C175B Pin 47 C175B Pin 51 Compare the above ambient temperature sensor resistances using the table below. Outside Air Temperature Ambient Air Temperature Sensor Value Celsius Fahrenheit Resistance (K ohms) -1.1° to 4.4° 30° to 40° 27.49 to 33.47 4.4° to 10° 40° to 50° 22.06 to 28.86 10° to 15.6° 50° to 60° 16.63 to 23.10 15.6° to 21.1° 60° to 70° 11.74 to 17.32 21.1° to 26.7° 70° to 80° 9.34 to 12.14 26.7° to 32.2° 80° to 90° 8.49 to 9.62 32.2° to 37.8° 90° to 100° 5.93 to 7.87 37.8° to 43.3° 100° to 110° 4.78 to 6.11 Does the resistance match the table specifications above? Yes GO to AE10 No GO to AE9 AE9 CHECK THE AMBIENT AIR TEMPERATURE SENSOR RESISTANCE Disconnect Ambient Air Temperature Sensor C132. Measure: Positive Lead Measurement / Action Negative Lead C132 Pin 1 Component Side C132 Pin 2 Component Side Compare the ambient temperature sensor resistances using the table below. Outside Air Temperature Ambient Air Temperature Sensor Value Celsius Fahrenheit Resistance (K ohms) -1.1° to 4.4° 30° to 40° 27.49 to 33.47 4.4° to 10° 40° to 50° 22.06 to 28.86 10° to 15.6° 50° to 60° 16.63 to 23.10 15.6° to 21.1° 60° to 70° 11.74 to 17.32 21.1° to 26.7° 70° to 80° 9.34 to 12.14 26.7° to 32.2° 80° to 90° 8.49 to 9.62 32.2° to 37.8° 90° to 100° 5.93 to 7.87 37.8° to 43.3° 100° to 110° 4.78 to 6.11 Does the resistance match the table specifications above? Yes The ambient air temperature sensor is operating correctly. REPAIR the circuits for high circuit resistance. No GO to AE11 AE10 CHECK THE AMBIENT AIR TEMPERATURE (AAT) SENSOR FOR OBSTRUCTIONS OR DEBRIS Check the area around the Ambient Air Temperature (AAT) sensor for any obstructions or debris such as leaves or paper. Is the area around the Ambient Air Temperature (AAT) sensor free from any obstructions or debris? Yes GO to AE11 No CLEAR all debris or obstructions as necessary to allow for the free flow of air around the Ambient Air Temperature (AAT) sensor. AE11 CHECK THE AMBIENT AIR TEMPERATURE (AAT) SENSOR OPERATION Disconnect Ambient Air Temperature (AAT) Sensor C132. Inspect the connector and wiring: water intrusion corrosion damaged pins pushed-out pins Are there any signs of water intrusion, corrosion, damaged or pushed out pins? Yes REPAIR the Ambient Air Temperature (AAT) sensor connector or wiring for any water intrusion, corrosion, damaged or pushed out pins. No INSTALL a new ambient air temperature sensor. Ambient Air Temperature Sensor Location Document download links> Ambient Air Temperature Sensor - Removal and Installation - 2018 Edge Workshop Manual.pdf Front Bumper Cover - Removal and Installation - 2018 Edge Workshop Manual.pdf Link to this FordParts webpage Good luck! Edited March 2 by Haz 1 Quote Link to comment Share on other sites More sharing options...
billw6560 Posted March 2 Author Report Share Posted March 2 Thanks for your very detailed diags and description. Quote Link to comment Share on other sites More sharing options...
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